Photocatalytic degradation of organic pollutants using yttrium and copper co-doped nickel aluminate

Photocatalytic degradation of organic pollutants using yttrium and copper co-doped nickel aluminate | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Photocatalytic degradation of organic pollutants using yttrium and copper co-doped nickel aluminate Anju Nair, Ancy Kurian, Shanmugam Sumathi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5295270/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 20 Jan, 2025 Read the published version in Environmental Science and Pollution Research → Version 1 posted 6 You are reading this latest preprint version Abstract Spinel nickel aluminate was synthesized using the sol-gel process and citric acid as a capping agent. Parent nickel aluminate, yttrium-doped nickel aluminate, and yttrium-copper co-doped nickel aluminate were synthesized and calcined at 800 °C for 4 hours. The synthesized spinels were used to enhance photocatalytic activity and can convert harmful organic dyes into simpler, less harmful molecules like CO 2 and H 2 O. The synthesized nanoparticles were characterized by various techniques, including XRD, UV-DRS, XPS, and SEM-EDAX. X-ray diffraction analysis helped in understanding the purity of phases, the lattice parameter, and the determination of average crystallite size. UV-DRS gave vital information about electronic property, i.e., band gap, by utilizing the Tauc plot method. The morphology of the nanoparticles was characterized by SEM (scanning electron microscopy), whereas elemental confirmation in the nickel aluminate lattice was carried out by EDAX. XPS provided information on the oxidation states of the ions present in the spinels. Photocatalysis was conducted against the organic dye crystal violet. Yttrium-doped nickel aluminate exhibited a higher photocatalytic activity in comparison to undoped nickel aluminate. This suggested improved activity in photocatalysis due to the insertion of yttrium into the lattice. Parameters such as pH, the effect of catalyst dosage, and the effect of concentration of dye were analyzed. Nickel aluminate yttrium copper co-doped nickel aluminate photocatalytic activity crystal violet Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 1. Introduction The current situation of water pollution poses a significant threat to both human health and the environment (Moe and Rheingans, 2006 ). Improper sanitation poses numerous illnesses for the inhabitants. Various studies found that pollution is caused by human activities (Blaisdell et al., 2019 ). Water bodies containing organic impurities and minerals are due to anthropogenic activities (Warren-Vega et al., 2023 ). The textile industry is one of the major producers of organic dye as a contaminant (Nasser Mohammed Hosny et al., 2023). Wastewater generated, even in smaller proportions, can affect the quality of water for aquatic organisms. The dyes, which are non-biodegradable, stay in the atmosphere for a longer duration and sometimes function as carcinogens. (Hassaan, Nemr and El, 2017 ; Nasser Mohammed Hosny et al., 2023). The major issue affecting humans is respiratory difficulties due to the inhalation of dye particles. A condition called respiratory sensitization with symptoms like sneezing, asthma, watery eyes, coughing, etc., is noticed (Hassaan, Nemr and El, 2017 ). There are several types of dyes: cationic, anionic, and non-ionic; among them, cationic dyes are the most toxic. (Foroutan et al., 2020 ; Noreen et al., 2021 ; Salah Omer et al., 2022 ). Cationic dyes are carcinogenic, hazardous, allergic dermatitis, teratogenic, etc. (Grassi et al., 2020; Salah Omer et al., 2022 ) Crystal violet (CV), a type of cationic dye, is largely used in the textile industry. It is used as a purple color in fabrics, silk, and printing ink (Au et al., 1979 ). Resident water bodies absorb this harmful water, which then turns into toxic. In the long term, it can cause damage to the cornea, skin rashes, problems in the digestive tract, and sometimes kidney failure (Jones and Falkinham III, 2003; Srinivas et al., 2023 ; Thomas and MacPhee, 1984 ). It is extremely important to remove such a toxic dye from wastewater (Ahmad and Ejaz, 2023 ; Arab, El Kurdi and Patra, 2022 ). Various methods for the removal of dye have been practiced, including coagulation, chemical oxidation, advanced oxidation process, filtration, reverse osmosis, adsorption, photocatalytic degradation, etc. (Ahmad and Ejaz, 2023 ). Photocatalytic degradation has been established as an eco-friendly, sustainable, and inexpensive method for the removal of dyes and converting them to H 2 O and CO 2 (P. Kowsalya, S. Uma Bharathi and M. Chamundeeswari, 2023 ). Photocatalysis uses semiconductors along with a light source to produce species that are responsible for redox reactions (Nasser Mohammed Hosny et al., 2023). The synthesis of semiconductor nanomaterials can be achieved through various methods such as ball milling, auto-combustion, hydrothermal, chemical vapor synthesis, and sol-gel method. Sol-gel is a very simple technique that produces homogenous material with great structure and particle size (Luo et al., 2017 ). For photocatalysis, we need a material with a lower band gap, a large surface area, and a smaller particle size (Khalid et al., 2024 ; Luo et al., 2017 ). Hence, we synthesize a spinel type of photocatalyst that has mechanical resistance, thermal stability, and hydrophobic. Nickel aluminate, a partially inverse spinel, is an efficient photocatalyst (Rohan Samkaria and Sharma, 2013 ). Several research studies exhibited compounds that could degrade crystal violet dye by photocatalytic degradation. A study (Singh et al., 2022 ) showed Fe doped La 0.7 Sr 0.3 MnO 3 by the solid-state method with a degradation rate of 81.9% in their work. Whereas a study (S. Ben Ameur et al., 2019 ) showed a degradation of crystal violet of 91.3% within 210 minutes. Strontium doped tin oxide was synthesized (Kaur et al., 2023 ) via the sol-gel approach and found a degradation of 67.8%. Synthesis of nickel doped barium hexaferrite (G. Muhiuddin et al., 2023 ) for photocatalytic degradation of crystal violet dye with an efficiency of 97%. Another study (S. Gouthamsri et al., 2023 ) showed a degradation of 100% with the synthesized compound zirconium-doped zinc oxide via the same route followed by us sol-gel approach. Yttrium and zinc doping and co-doping on CeO 2 (Sharma & Pandey, 2022 ) by co-precipitation route and found the degradation percentage of CV to be 100% for both within a duration of 7 hours. For the present work, we have synthesized yttrium and copper, yttrium-co-doped nickel aluminate for photocatalytic degradation of crystal violet dye under ultraviolet light. 2. Experimental section 2.1 Materials & Methods Nickel nitrate (Ni(NO 3 ) 2 .6H 2 O, 99.0%), Aluminium nitrate (Al(NO 3 ) 3 .9H 2 O, 98.0%), Yttrium nitrate (Y(NO 3 ) 3 .6H 2 O, 99.9%), Cupric nitrate trihydrate (Cu(NO 3 ) 2 .3H 2 O, 99.5%), and Citric acid (C 6 H 8 O 7 , 99.5%) were used as starting materials for the synthesis of Nickel aluminate (NiAl 2 O 4 ), Yttrium-doped Nickel Aluminate (NiAl 2 − x Y x O 4 ) and Yttrium-copper co-doped nickel aluminate. These chemicals are sourced from SD fine chemicals. 2.2 Synthesis of Nickel aluminate, Yttrium-doped and Yttrium-Copper co-doped nickel aluminate by sol-gel method The catalyst was made by dissolving nickel nitrate in distilled water and then citric acid was added dropwise at 30°C for 30 minutes to the nickel nitrate solution and then stirred. In another beaker, aluminium nitrate, yttrium nitrate and copper nitrate were dissolved in water separately for the yttrium and copper doped nickel aluminate. These solutions were added to the nickel nitrate and citric acid mixture and heated at 60°C for 1 h. Then the temperature was increased to 80°C for 2 hours. Once the volume was reduced, the prepared gel was kept in the oven for drying at 120°C for 12 hours. It was ground well and kept in a muffle furnace for calcination at 800°C for 4 hours. The calcined material was ground, and the photocatalyst was formed (Fig. 1 ). The same procedure was followed with and without copper and yttrium for copper and pristine nickel aluminate. The prepared undoped, yttrium-doped, and (Cu, Y) co-doped nickel aluminate was analyzed by various characterization techniques. 2.5 Characterization The crystal structure identification of the synthesized photocatalyst is executed by X-ray powder diffraction (XRD-BRUKER D8 Advanced) instrument with diffraction angle of 10–70°. Optical properties were analyzed using the UV-Vis-NIR Spectrometer (UV-Visible Diffuse Reflectance) (JASCO V-670). Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDAX) of the spinels was done with the ZESIS EVO18 SEM instrument. Photocatalysis was done using (JASCO-730) UV-Vis Spectrophotometer. 2.6 Photocatalytic test The photocatalytic degradation of crystal violet (10 ppm) was considered against a photocatalyst (10 mg) under irradiation with 250 W UV light for 120 minutes. Before UV light irradiation, sample was subjected to dark conditions for 30 minutes to attain adsorption-desorption equilibrium. 50 ml of 10 ppm Crystal Violet dye was poured into a quartz tube, and 3 ml sample aliquot was taken every 30 minutes until 120 minutes. Aliquot was characterized by UV-Vis (JASCO V-730) spectrometer within 200–800 nm. The degradation was calculated using the below-given formula. % degradation = \(\:\:\:\frac{{C}_{0}-{C}_{t}}{{C}_{0}}\times\:100\) (1) Here, C 0 is the initial concentration, the final concentration given by C t at time t. 3. Result and Discussion 3.1 Structural Analysis The pattern of XRD (Fig. 2 ) shows the phase purity of the novel substituted spinel compound which includes increasing concentrations of yttrium and copper. There are no additional peaks due to the insertion of yttrium and copper into the lattice, suggesting the primary nickel-aluminate structure is retained. The peaks are indexed with ICDD No. 01-071-0965, and hence there is complete formation of NiAl 2 O 4 . The average crystallite size is calculated by the Debye-Scherrer formula by using the most intense peak (311). This provides information about the grain size and crystallinity of the spinel. The high intense peak (311) slightly shifted to lower angle due to the substitution of yttrium into the lattice. The shifting increases when copper is co-doped in yttrium substituted nickel aluminate. This could be due to the higher ionic radii copper and yttrium than nickel and aluminium (Anderson, Mehandru and Smialek, 1985 ; Elakkiya, Abhishekram and Sumathi, 2019 ). Also, the intensity of (440) peak increase due to co-doping of copper in the yttrium doped aluminate. The band gap of the nickel aluminate was calculated using the Tauc plot from the data obtained from UV-DRS. There is a significant decrease in the band gap in comparison to the parent nickel aluminate. The reduction signifies a shift in electronic structure and potentially enhanced photocatalytic activity. A smaller band gap facilitates the transition from the valence band to the conduction band and helps the reaction on the catalytic surface. This significant decrease in band gap implies the practical application of yttrium-doped and co-doped nickel aluminate in photocatalytic activity due to electronic transition. Table 1 Average crystallite size and bandgap NiAl 2 − x Y x O 4 Average crystallite size (nm) Band-Gap x = 0.0 9.35 2.271 x = 0.03 7.33 2.221 x = 0.05 6.38 2.213 x = 0.07 6.77 2.21 x = 0.1 6.04 2.189 NAY07C 20.30 1.546 NAY10C 28.55 1.422 $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:$$ $$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:D=\:\frac{k\lambda\:}{\beta\:cos\theta\:}$$ 2 Where D is the average crystallite size, λ is wavelength, θ is Bragg’s angle, β is (FWHM) full-width at half maximum and k take a value of 0.9. The Tauc-plot was used to find band gap energy which was calculated using Eq. ( 3 ) $$\:\alpha\:hv=A{(hv-{E}_{g})}^{1/2}$$ 3 Here α is absorption coefficient, h is Planck’s constant, E g is optical band-gap υ is photon frequency, and A is a constant. Band Gap was calculated by extrapolating on the x-axis, which gives the absorption energy (Fig. 3 ). The band gap was calculated to be 2.271, 2.221, 2.213, 2.21, 2.189, 1.546, and 1.422 eV for x = 0, x = 0.03. x = 0.05, x = 0.07, x = 0.1, NAY07C, and NAY10C, respectively. The decrease of the band gap helps in the larger mineralization of dye due to the generation of electron-hole pairs. Since the band gap for yttrium-doped nickel aluminate is in the Ultraviolet region, photocatalysis was conducted under UV light. Scanning electron microscopy (SEM) provides significant insights into the morphology of the synthesized compounds. SEM was recorded for selected compositions to understand the morphology Pristine compound showed heterogeneous shaped particles. In the case of yttrium doped compositions rock like structure with cavities were observed (Fig. 4 ). Field Emission Scanning Electron Microscopy images of copper and yttrium-co-doped nickel aluminate of Ni 0.9 Cu 0.1 Al 1.9 Y 0.1 O 4 showed slightly spherical shaped particles with agglomeration (Fig. 5 ). Further, elemental confirmation was done through energy dispersive X-ray spectroscopy (EDAX), which confirmed the elements nickel, aluminum, yttrium, and oxygen, thus validating the composition of the spinels. These characterizations not only confirm the phase and morphology but also give a deeper understanding of their applications. XPS was used to understand the oxidation states of synthesized copper and yttrium co-doped nickel aluminate NAY10C (Ni 0.9 Cu 0.1 Al 1.9 Y 0.1 O 4 ). X-ray photoelectron spectroscopy (XPS) shows the presence of nickel, aluminium, yttrium, copper, and oxygen in the spectra. Figure 6 a shows survey spectra of the co-doped sample. Nickel (Fig. 6 b) displays four peaks, among which the peaks at 855.80 eV and 873.26 eV represent Ni 2p 3/2 and Ni 2p 1/2 respectively (Prieto et al., 2012 ). The peaks at 862.17 eV, and 880.13 eV depict the satellite peaks corresponding to Ni 2p (Elakkiya, Abhishekram and Sumathi, 2019 ). Aluminium also shows four peaks in the XPS spectra at 68.27 eV, 74.01 eV, 75.00 eV (Kunde, Sehgal and Ganguli, 2021 ) and 77.28 eV which can be seen in Fig. 6 c (Irie et al., 2017 ; Kozlica, Kokalj and Milošev, 2021 ). Yttrium peaks were confirmed from the literature indicated in Fig. 6 d. Peak at 157.39 eV illustrates Y 3d 5/2 (Dhilleswara Rao Vaddi et al., 2023 ) whereas 158.17 eV and 159.15 eV describe the Y 3d 3/2 state of Y + 3 (Dhilleswara Rao Vaddi et al., 2023 ; S. Muruganandam et al., 2023 ). Cu 2p showed five peaks, as seen in Fig. 6 e. Binding energy 934.06 eV depicts 2p 3/2 of copper (Eléa Vernack et al., 2023 ) and that of 941.77 eV confirmed by the resource (Amun Amri et al., 2013) whereas 954.68 eV shows the 2p 1/2 that is Cu + 2 state and satellite peaks are illustrated at 943.67 eV, and 962.41 eV (Kirankumar, Mayank and Sumathi, 2019 ). Oxygen 1s peaks are shown in Fig. 6 f. There are two peaks that are confirmed from the literature, which includes 530.86 eV and 533.72 eV of O-H hydroxyl group and O 1s, respectively (Hany, Khalaf and Ibrahim M.A. Mohamed, 2024). 3.2 Photocatalytic activity The photocatalytic activity of nickel aluminate and nickel aluminate doped with yttrium and copper was taken into consideration. Catalytic activity against the organic pollutant crystal violet was demonstrated under UV light. Degradation efficiency was calculated using Eq. 1. 3.2.1 Effect of insertion of metal ion into the lattice Photodegradation was performed using yttrium-doped nickel aluminate NiAl 1 − x Y x O 4 (x = 0, 0.03, 0.05, 0.07, and 0.1). 250 W UV lamp was used to irradiate 50 ml of 10 ppm crystal violet dye with 10 mg of the catalyst. Before irradiation the mixture was kept under dark condition with stirring for 30 minutes. The sample was withdrawn in an interval of 30 minutes and UV-Vis spectrum was recorded after centrifugation. After 120 minutes of photodegradation, the parent nickel aluminate exhibited 83.54% degradation efficiency. As illustrated in Fig. 7 , the highest yttrium concentration (x = 0.1) demonstrated a remarkable degradation rate of 97.40% for the crystal violet dye, indicating its superior catalytic efficiency. The catalytic activity was increased with increased in the dopant concentration. The high level of degradation suggests that yttrium-doped nickel aluminate is a more effective catalyst compared to its undoped counterpart. The enhanced photocatalytic performance is likely due to the reduction in band gap, which facilitates better absorption of UV light. Consequently, the mineralization of the crystal violet dye under UV light is significantly improved. Table 2 Photocatalytic degradation of crystal violet. NiAl 2 − x Y x O 4 Degradation percentage (%) x = 0 83.54 x = 0.03 88.21 x = 0.05 92.04 x = 0.07 93.78 x = 0.1 97.40 3.2.2 Effect of catalyst dosage The best dopant concentration was identified and the photocatalytic activity of NiAl 0.9 Y 0.1 O 4 was carried out using 10 ppm of CV dye with 5 mg, 10 mg, and 20 mg of catalyst. The degradation percentage observed with a 10 mg catalyst was 97.39%, but 5 mg of the catalyst yielded a degradation of 95.96%. The degradation efficiency 97.76% was recorded with a 20 mg of the catalyst. Due to the minimal differences in performance between the 10 mg and 20 mg catalysts, the 10 mg dosage was selected for further optimization. (Fig. 8 ). This choice balances high efficiency with practical considerations, such as cost and ease of handling. As a result, using 10 mg of catalyst strikes a balance between performance and feasibility for ongoing studies. 3.2.3 Effect of concentration of crystal violet dye To investigate the impact of varying dye concentrations on degradation efficiency, solutions with concentrations of 25 ppm and 50 ppm were prepared and subjected to UV irradiation using 10 mg of NiAl 0.9 Y 0.1 O 4 . The results indicated that the 25 ppm dye solution achieved a degradation rate of 89.61%. In contrast, the 50 ppm dye solution exhibited a significantly lower degradation rate of 54%. This reduction in degradation efficiency with increasing dye concentration suggests that higher pollutant levels reduce the photocatalyst's effectiveness. The decreased degradation at higher concentrations is likely due to the increased number of dye molecules, which may lead to competitive adsorption on the catalyst surface and reduce the availability of active sites (Ajithkumar, Mohana and Sumathi, 2019 ). Consequently, this trend underscores the challenge of achieving high degradation rates in solutions with elevated pollutant concentrations. (Fig. 9 ). The findings highlight the need for optimizing catalyst dosage and concentration to enhance the photocatalytic performance. 3.2.4 Effect of pH The effect of pH plays a vital role in the degradation of dyes; it can either increase or decrease the activity of the catalyst. pH was adjusted to 4, 7 and 11 using HCl and NaOH respectively, using a pH meter. From Fig. 10 we can understand that with the increase in pH, the activity was increased. pH 4 indicated an 81% deterioration as exterior sites became positively charged. At pH = 7 resulted in 84% degradation, but pH = 11 resulted in a significant increase in photocatalytic activity of 96%, this is considered the optimum degradation state due to an increase in OH − ions. We can see that there has been a rise in OH − , which increases efficiency (Ajithkumar, Mohana and Sumathi, 2019 ). 3.2.5 Effect of scavengers The key role in photocatalysis is the production of reactive species including holes (h + ), hydroxide radical (OH.), electron (e − ), and superoxide radical (O 2 − .), which helps in breaking pollutant into smaller fragments. It is of foremost importance to understand the mechanism of photocatalytic degradation of CV against the synthesized photocatalyst. Initially, 10 ppm of CV was stirred in a dark condition, after which 1mM of scavengers were added to this solution and irradiated with 250 W UV light. Aliquots of the sample were taken for every 30 minutes and continued to 2 hours. Addition of Isopropyl alcohol (OH.) and EDTA (h + ) showed not much change in degradation, suggesting that OH. and h + was not involved in the reaction. The degradation efficiency of crystal violet was observed to decrease slightly in the presence of benzoquinone (O 2 − .) and silver nitrate (e − ) in 120 minutes. The reduction in efficiency highlights that O 2 − . radicals and electrons (e − ) play a significant role in the photocatalytic degradation process. (Fig. 11 ). The presence of these scavengers indicates that both superoxide radicals and electrons are crucial for the effective breakdown of the dye. Their interaction with the crystal violet molecules facilitates the degradation mechanism. 3.2.7 Optimized condition for copper yttrium co-doped nickel aluminate Using the optimized conditions such as 10 ppm, 10 mg of the catalyst, pH = 11 (alkaline condition) the photocatalytic activity of copper and yttrium doped nickel aluminate NAY10C (Ni 0.9 Cu 0.1 Al 1.9 Y 0.1 O 4 ) was carried out. Under these conditions, the photocatalysis was conducted under 250 W UV light. The co-doped catalyst NAY10C achieved a remarkable degradation rate of 96.32% in 90 min itself, surpassing the performance of yttrium-doped nickel aluminate (Fig. 12 ). This suggests that the co-doped catalyst offers superior photocatalytic activity under the optimized conditions. 3.2.6 Recyclability studies To understand the stability of the prepared photocatalyst, it is vital to carry out reusability studies. 10 mg of (x = 0.1) of yttrium-doped nickel aluminate was studied against 10 ppm of crystal violet dye. The photocatalysis was carried out for 120 minutes under a 250 W UV lamp (Fig. 13 ). After 1st cycle the photocatalyst was washed with ethanol (C 2 H 5 OH) for desorption and it was washed with distilled water. The washed catalyst was dried and went through another cycle. Degradation after 1st cycle was found to be 98.65%. The percentage degradation in the second cycle was 97.19%, and in the third cycle, it was 95%. This decrease in degradation efficiency demonstrates the photocatalyst's stability and reusability over multiple cycles. The minimal reduction in performance indicates that the prepared catalyst maintains its high efficiency even after repeated use. These results highlight the robustness and durability of the catalyst in photocatalytic applications. 3.6 Possible mechanism for degradation of CV The photocatalytic degradation mechanism involving yttrium-doped nickel aluminate begins with the absorption of photons (hν), leading to the excitation of electrons (e − ) from the valence band (VB) to the conduction band (CB), resulting in the formation of electron-hole pairs (e − (CB) and h + (VB)). The excited electron in the conduction band interacts with nearby oxygen molecules. This interaction leads to the formation of superoxide radicals (.O₂⁻). The superoxide radicals subsequently react with protons (H⁺), facilitating a chemical transformation. This reaction results in the production of hydrogen peroxide (H 2 O 2 ), which is a key intermediate in oxidation processes. Hydrogen peroxide undergoes reduction, in the presence of catalyst, breaking down into hydroxyl radicals. These hydroxyl radicals (OH•) are highly reactive species that contribute to further oxidative reactions, significantly influencing the degradation of organic compounds. In the final stage, the superoxide radicals (.O₂⁻) directly interact with the crystal violet dye (CV). These reactions lead to the breakdown of the dye molecules into smaller degradation products, ultimately resulting in the decolorization and mineralization of the dye. This series of reactions highlights the role of superoxide radicals and hydroxyl radicals in the photocatalytic degradation process (Singh et al., 2022 ). 4. Conclusion Yttrium-doped and copper-yttrium co-doped nickel aluminate was synthesized via a very simple sol-gel method with a calcination temperature of 800°C for 4 hours. SEM results showed an agglomerated structure in the samples. Parent nickel aluminate, along with doped and co-doped samples were analyzed by XRD, UV-DRS, SEM-EDAX, XPS, and FE-SEM. Insertion of yttrium and copper decreased the band gap, and we can see a shift in peaks towards the lower angle in the XRD. The cationic dye crystal violet is used to understand the photocatalytic activity of the prepared photocatalyst. Parameters including pH, catalyst dosage, and dye concentration were analyzed. With increasing pH, there is greater degradation efficiency in doped and co-doped samples. Based on the reactions performed, it is evident that both yttrium-doped and co-doped catalysts exhibit promising photocatalytic efficiency. We can conclude that both yttrium-doped and copper co-doped samples hold significant potential as viable catalysts for photodegradation applications. Declarations Acknowledgments: We would like to thank the VIT university management for providing all necessary facilities and permission for research and to carry out the experiments. Ethical approval- Not applicable. Consent to Participate- Not applicable. Consent to Publish- We give our consent to publish the paper in this journal. Data availability statement- All data analyzed during the study has been submitted in this manuscript. Authors Contributions - Material synthesis, formal analysis, methodology, and writing original draft was conducted by Anju Nair. Review and writing were made by Ancy Kurian and Abima S. Conceptualization, Validation, and Supervision was made by Shanmugam Sumathi. Funding - No external funding is involved. Competing Interests - The authors declare no competing interests. References Ahmad R, Ejaz MO (2023) Efficient adsorption of crystal violet (CV) dye onto benign chitosan-modified l-cysteine/bentonite (CS-Cys/Bent) bionanocomposite: Synthesis, characterization and experimental studies. Dyes Pigm [online] 216:111305. https://doi.org/10.1016/j.dyepig.2023.111305 Ajithkumar P, Mohana S, Sumathi S (2019) Synthesis, characterization, optical and photocatalytic activity of yttrium and copper co-doped zinc ferrite under visible light. J Mater Sci: Mater Electron 31(2):1168–1182. https://doi.org/10.1007/s10854-019-02628-8 Amun Amri, Duan X, Yin C, Zhong Tao Jiang M, Mahbubur Rahman, Pryor T (2013) Solar absorptance of copper–cobalt oxide thin film coatings with nano-size, grain-like morphology: Optimization and synchrotron radiation XPS studies. Appl Surf Sci 275:127–135. https://doi.org/10.1016/j.apsusc.2013.01.081 Anderson AB, Mehandru SP, Smialek JL (1985) Dopant Effect of Yttrium and the Growth and Adherence of Alumina on Nickel-Aluminum Alloys. J Electrochem Soc 132(7):1695–1701. https://doi.org/10.1149/1.2114193 Arab C, El Kurdi R, Patra D (2022) Zinc curcumin oxide nanoparticles for enhanced adsorption of Congo red: kinetics and adsorption isotherms study. Mater Today Chem 23:100701. https://doi.org/10.1016/j.mtchem.2021.100701 Au W, Butler MA, Bloom SE, Matney TS (1979) Further study of the genetic toxicity of gentian violet. Mutat Research/Genetic Toxicol 66(2):103–112. https://doi.org/10.1016/0165-1218(79)90054-5 Blaisdell J, Turyk ME, Almberg KS, Jones RM, Stayner LT (2019) Prenatal exposure to nitrate in drinking water and the risk of congenital anomalies. Environ Res 176:108553. https://doi.org/10.1016/j.envres.2019.108553 Vaddi DR, Vinukonda K, Patnala RK, Kanithi Y, Gurugubelli TR, Bae J, Koutavarapu R, Lee D-Y, Shim J (2023) Effect of yttrium doping on the crystal structure, optical, and photocatalytic properties of hydrothermally synthesized ZnO nanorods. Mater Sci Engineering: B 296:116664–116664. https://doi.org/10.1016/j.mseb.2023.116664 Eléa Vernack S, Zanna, Seyeux A, Costa D, Chiter F, Tingaut P, Marcus P (2023) ToF-SIMS, XPS and DFT study of the adsorption of 2-mercaptobenzothiazole on copper in neutral aqueous solution and corrosion protection in chloride solution. Corros Sci 210:110854–110854. https://doi.org/10.1016/j.corsci.2022.110854 Foroutan R, Mohammadi R, Sohrabi N, Sahebi S, Farjadfard S, Esvandi Z, Ramavandi B (2020) Calcined alluvium of agricultural streams as a recyclable and cleaning tool for cationic dye removal from aqueous media. Environ Technol Innov 17:100530. https://doi.org/10.1016/j.eti.2019.100530 Muhiuddin G, Bibi I, Nazeer Z, Majid F, Kamal S, Kausar A, Raza Q, Alwadai N, Ezzine S, Iqbal M (2023) Synthesis of Ni doped barium hexaferrite by microemulsion route to enhance the visible light-driven photocatalytic degradation of crystal violet dye. Ceram Int 49(3):4342–4355. https://doi.org/10.1016/j.ceramint.2022.09.319 Grassi P, Drumm FC, Spannemberg SS, jordana georgin, Tonato D, Mazutti M, Gonçalves Janaína, Leandro M Guilherme Luiz Dotto and Sérgio Luiz Jahn (2020) Solid wastes from the enzyme production as a potential biosorbent to treat colored effluents containing crystal violet dye. Environ Sci Pollut Res, 27(10):10484–10494. https://doi.org/10.1007/s11356-020-07664-0 Hany, Khalaf MM, Ibrahim MA, Mohamed (2024) XPS analysis, voltammetric, and impedance characteristics of novel heterogeneous biphosphates based on Cu/Ni for tri(ammonium) phosphate oxidation: A new direction for material processing in fuel technology. Fuel 356:129618–129618. https://doi.org/10.1016/j.fuel.2023.129618 Hassaan M, Nemr A, El A (2017) Health and Environmental Impacts of Dyes: Mini Review. Nemr Health Environ Impacts Dyes: Mini Rev Am J Environ Sci Eng [online] 1(3):64–67. https://doi.org/10.11648/j.ajese.20170103.11 Irie Y, Maruo Y, Kataoka N, Tanaka H, Kinoshita K, Kishida S (2017) AFM and XPS study from surfaces of native oxide/Al-metal. Procedia Eng 216:182–189. https://doi.org/10.1016/j.proeng.2018.04.001 Jones JJ, Falkinham III, J.O (2003) Decolorization of Malachite Green and Crystal Violet by Waterborne Pathogenic Mycobacteria. Antimicrob Agents Chemother [online] 47(7):2323–2326. https://doi.org/10.1128/aac.47.7.2323-2326.2003 Kaur M, Prasher D, Dhiman V, Murugesan P, Ghosh D, Sharma R (2023) Green energy induced photocatalytic decomposition of methylene blue and crystal violet dyes by strontium doped tin oxide nanoparticles and its antibacterial activity. Physica B 661:414924–414924. https://doi.org/10.1016/j.physb.2023.414924 Khalid H, Haq Aul, Zahoor AF, Irfan A, Zaki A (2024) An investigation of Ca-doped MgO nanoparticles for the improved catalytic degradation of thiamethoxam pesticide subjected to visible light irradiation. Sci Rep 14(1). https://doi.org/10.1038/s41598-024-51738-9 Kirankumar VS, Mayank N, Sumathi S (2019) Photocatalytic performance of cerium doped copper aluminate nanoparticles under visible light irradiation. J Taiwan Inst Chem Eng 95:602–615. https://doi.org/10.1016/j.jtice.2018.09.020 Kozlica DK, Kokalj A, Milošev I (2021) Synergistic effect of 2-mercaptobenzimidazole and octylphosphonic acid as corrosion inhibitors for copper and aluminium – An electrochemical, XPS, FTIR and DFT study. Corros Sci 182:109082–109082. https://doi.org/10.1016/j.corsci.2020.109082 Kunde GB, Sehgal B, Ganguli AK (2021) Modified EISA synthesis of NiAl 2 O 4 /MWCNT composite mesoporous free-standing film as a potential electrochemical capacitor material. J Alloys Compd 856:158019–158019. https://doi.org/10.1016/j.jallcom.2020.158019 Luo J, Wang S, Liu W, Tian C, Wu J, Zu X, Zhou W, Yuan X, Xiang X (2017) Influence of different aluminum salts on the photocatalytic properties of Al doped TiO2 nanoparticles towards the degradation of AO7 dye. Sci Rep 7(1). https://doi.org/10.1038/s41598-017-08216-2 Moe CL, Rheingans RD (2006) Global challenges in water, sanitation and health. J Water Health 4(S1):41–57. https://doi.org/10.2166/wh.2006.0043 Gomaa NMH, Elmahgary I, M.G. and, Ibrahim M (2023) ZnO doped C: Facile synthesis, characterization and photocatalytic degradation of dyes. Sci Rep 13(1). https://doi.org/10.1038/s41598-023-41106-4 Noreen S, Tahira M, Ghamkhar M, Hafiz I, Bhatti HN, Nadeem R, Murtaza MA, Yaseen M, Sheikh AA, Naseem Z, Younas F (2021) Treatment of textile wastewater containing acid dye using novel polymeric graphene oxide nanocomposites (GO/PAN,GO/PPy, GO/PSty). J Mater Res Technol 14:25–35. https://doi.org/10.1016/j.jmrt.2021.06.007 Kowsalya P, Uma Bharathi S, Chamundeeswari M (2023) Photocatalytic treatment of textile effluents by biosynthesized photo-smart catalyst: an eco-friendly and cost-effective approach. Environment, Development and Sustainability . https://doi.org/10.1007/s10668-023-03172-6 Prieto P, Nistor V, Nouneh K, Oyama M, Abd-Lefdil M, Díaz R (2012) XPS study of silver, nickel and bimetallic silver–nickel nanoparticles prepared by seed-mediated growth. Appl Surf Sci 258(22):8807–8813. https://doi.org/10.1016/j.apsusc.2012.05.095 Rohan Samkaria, Sharma V (2013) Effect of rare earth yttrium substitution on the structural, dielectric and electrical properties of nanosized nickel aluminate. Mater Sci Engineering: B 178(20):1410–1415. https://doi.org/10.1016/j.mseb.2013.08.017 Ben Ameur S, BelHadjltaief H, Duponchel B, Leroy G, Amlouk M, Hajer Guermazi and Samir Guermazi (2019) Enhanced photocatalytic activity against crystal violet dye of Co and In doped ZnO thin films grown on PEI flexible substrate under UV and sunlight irradiations. Heliyon 5(6):e01912–e01912. https://doi.org/10.1016/j.heliyon.2019.e01912 Gouthamsri S, Malla Ramanaiah K, Basavaiah, Jaya Rao K (2023) Zr-doped ZnO nanohybrid via Glycine mediated sol-gel approach as benign supporter for degradation of Crystal violet and antibacterial performance. Results Chem 6:101080–101080. https://doi.org/10.1016/j.rechem.2023.101080 Muruganandam S, Kannan S, Anishia SR, Krishnan P (2023) Electrochemical performance of Yttrium doped SnO 2 –NiO nanocomposite for energy storage applications. J Phys Chem Solids 179:111420–111420. https://doi.org/10.1016/j.jpcs.2023.111420 salah omer A, Naeem AE, Abd-Elhamid G, Farahat AIOM, El-Bardan OA, Soliman AMA, H. and, Nayl AA (2022) Adsorption of crystal violet and methylene blue dyes using a cellulose-based adsorbent from sugarcane bagasse: characterization, kinetic and isotherm studies. J Mater Res Technol 19:3241–3254. https://doi.org/10.1016/j.jmrt.2022.06.045 Sharma PK, Pandey OP (2022) Enhanced photocatalytic activity with metal ion doping and co-doping in CeO 2 nanoparticles. Solid State Sci 126:106846. https://doi.org/10.1016/j.solidstatesciences.2022.106846 Singh B, Singh P, Siddiqui S, Singh D, Gupta M (2022) Wastewater treatment using Fe-doped perovskite manganites by photocatalytic degradation of methyl orange, crystal violet and indigo, carmine dyes in tungsten bulb/sunlight. J Rare Earths 1311–1322. https://doi.org/10.1016/j.jre.2022.09.010 Srinivas S, Durga Abhishay A, Kusuma A, Gowthami Y, Gummadi Sowgandh and Meena Vangalapati (2023) Optimization, kinetics and thermodynamics for the removal of crystal violet dye using synthesized FeNPs from Carica papaya leaves extract. Materials Today: Proceedings . https://doi.org/10.1016/j.matpr.2023.04.035 Thomas SM, MacPhee DG (1984) Crystal violet: a direct-acting frameshift mutagen whose mutagenicity is enhanced by mammalian metabolism. Mutat Res Lett [online] 140(4):165–167. https://doi.org/10.1016/0165-7992(84)90071-x Elakkiya V, Abhishekram. R, Sumathi S (2019) Copper doped nickel aluminate: Synthesis, characterisation, optical and colour properties. Chin J Chem Eng 27(10):2596–2605. https://doi.org/10.1016/j.cjche.2019.01.008 Warren-Vega WM, Campos-Rodríguez A, Zárate-Guzmán AI, Romero-Cano LA (2023) A Current Review of Water Pollutants in American Continent: Trends and Perspectives in Detection, Health Risks, and Treatment Technologies. Int J Environ Res Public Health [online] 20(5):4499–4499. https://doi.org/10.3390/ijerph20054499 Supplementary Files floatimage1.jpeg Cite Share Download PDF Status: Published Journal Publication published 20 Jan, 2025 Read the published version in Environmental Science and Pollution Research → Version 1 posted Editorial decision: Major Revision 22 Nov, 2024 Reviewers agreed at journal 29 Oct, 2024 Reviewers invited by journal 28 Oct, 2024 Editor invited by journal 28 Oct, 2024 Editor assigned by journal 25 Oct, 2024 First submitted to journal 24 Oct, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5295270","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":371418891,"identity":"033a92fc-4eeb-407c-b923-c562d09c83af","order_by":0,"name":"Anju Nair","email":"","orcid":"","institution":"Vellore Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Anju","middleName":"","lastName":"Nair","suffix":""},{"id":371418892,"identity":"5b864942-05a2-4a05-91ac-7305adeba7a4","order_by":1,"name":"Ancy Kurian","email":"","orcid":"","institution":"Vellore Institute of Technology","correspondingAuthor":false,"prefix":"","firstName":"Ancy","middleName":"","lastName":"Kurian","suffix":""},{"id":371418893,"identity":"2fb31faa-6895-46aa-878d-61fc825671aa","order_by":2,"name":"Shanmugam Sumathi","email":"data:image/png;base64,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","orcid":"","institution":"VIT University","correspondingAuthor":true,"prefix":"","firstName":"Shanmugam","middleName":"","lastName":"Sumathi","suffix":""}],"badges":[],"createdAt":"2024-10-19 15:37:56","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5295270/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5295270/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s11356-025-35913-7","type":"published","date":"2025-01-20T15:57:50+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":68445355,"identity":"3398d409-4d77-49df-960b-b205ebfd0f82","added_by":"auto","created_at":"2024-11-07 10:34:26","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":83198,"visible":true,"origin":"","legend":"\u003cp\u003eSol-gel synthesis approach\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/4d8f6071dede5cf472f1e22b.png"},{"id":68445035,"identity":"f6d2cee6-cca8-4a75-b919-8b5acccdb097","added_by":"auto","created_at":"2024-11-07 10:26:26","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":199692,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns for NiAl2-xYxO4 and copper co-doped (NAY07C (Ni0.9Cu0.1Al1.93Y0.07O4) and NAY10C (Ni0.9Cu0.1Al1.9Y0.1O4) samples\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/7dde112d934e3286b287a151.png"},{"id":68445357,"identity":"2431f9c2-0be8-4756-aabf-dbc71500c53e","added_by":"auto","created_at":"2024-11-07 10:34:26","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":194708,"visible":true,"origin":"","legend":"\u003cp\u003eBand gap of the NiAl2-xYxO4 and copper co-doped samples (NAY07C and NAY10C)\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/2fa5171328b797c0a1ff0f40.png"},{"id":68445034,"identity":"71809795-7747-4cc6-ae88-e5dd89e994ee","added_by":"auto","created_at":"2024-11-07 10:26:26","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":99884,"visible":true,"origin":"","legend":"\u003cp\u003eScanning Electron Microscopy (SEM)-EDAX of \u003cstrong\u003e(a)\u003c/strong\u003e x=0 \u003cstrong\u003e(b)\u003c/strong\u003e x=0.03 \u003cstrong\u003e(c) \u003c/strong\u003ex=0.1\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/0c6f6b96062535d30d081794.png"},{"id":68445360,"identity":"9328bca6-5e44-4466-86e8-78fd6a50002d","added_by":"auto","created_at":"2024-11-07 10:34:26","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":185077,"visible":true,"origin":"","legend":"\u003cp\u003eFE-SEM images of NAY10C (Yttrium, Copper) co-doped nickel aluminate\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/373c34882aa7bc4e5dbebd60.png"},{"id":68445356,"identity":"b114ff15-6af0-4f00-aecf-79c1860e2b07","added_by":"auto","created_at":"2024-11-07 10:34:26","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":435630,"visible":true,"origin":"","legend":"\u003cp\u003eXPS spectra (\u003cstrong\u003ea\u003c/strong\u003e) Survey scan (\u003cstrong\u003eb\u003c/strong\u003e) deconvoluted Ni 2p (\u003cstrong\u003ec\u003c/strong\u003e) deconvoluted Al 2p (\u003cstrong\u003ed\u003c/strong\u003e) deconvoluted Y 3d (\u003cstrong\u003ee\u003c/strong\u003e) deconvoluted Cu 2p (\u003cstrong\u003ef\u003c/strong\u003e) deconvoluted O 1s\u003c/p\u003e","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/2efd5a9ac8a08e1dfbbc0cd8.png"},{"id":68445036,"identity":"1c681cbd-5203-4010-9ddb-c10699063f96","added_by":"auto","created_at":"2024-11-07 10:26:26","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":202047,"visible":true,"origin":"","legend":"\u003cp\u003ePhotocatalytic degradation of crystal violet\u003cstrong\u003e \u003c/strong\u003eunder UV light\u003c/p\u003e","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/600064512636736f0c01009a.png"},{"id":68445358,"identity":"2f8b4e3d-1a7a-4c48-9ddc-2c353c168e5f","added_by":"auto","created_at":"2024-11-07 10:34:26","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":105983,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of the catalyst dosage on the photocatalytic degradation\u003c/p\u003e","description":"","filename":"floatimage9.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/3e6ea624b1c4c89624deaf44.png"},{"id":68446154,"identity":"68aedff6-027e-40bf-b15b-1c342fa37bab","added_by":"auto","created_at":"2024-11-07 10:42:26","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":271909,"visible":true,"origin":"","legend":"\u003cp\u003eCrystal violet dye with 10 ppm, 25 ppm and 50 ppm\u003c/p\u003e","description":"","filename":"floatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/e1b912448e616fe5d8eacdc2.png"},{"id":68445039,"identity":"59bd9a68-bf06-455f-927e-58de01506ada","added_by":"auto","created_at":"2024-11-07 10:26:26","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":1290448,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of pH on degradation of crystal violet\u003c/p\u003e","description":"","filename":"floatimage11.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/caed41f7e63bd2afa0e0d4eb.png"},{"id":68445047,"identity":"9dc5e72a-5925-4baa-a7e9-6fd0368c657d","added_by":"auto","created_at":"2024-11-07 10:26:26","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":139065,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of scavengers on the degradation of Crystal violet\u003c/p\u003e","description":"","filename":"floatimage12.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/2740bcfb0352215adcb0c2a3.png"},{"id":68445044,"identity":"f4a7feef-d1f8-4d83-9c6f-340c7b6f0adf","added_by":"auto","created_at":"2024-11-07 10:26:26","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":167281,"visible":true,"origin":"","legend":"\u003cp\u003eDegradation of crystal violet under optimized conditions\u003c/p\u003e","description":"","filename":"floatimage13.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/9ddb7fbd1d1e56ef4e6d2048.png"},{"id":68445362,"identity":"7812fc9d-d1b5-488d-8597-6c1bae8a43eb","added_by":"auto","created_at":"2024-11-07 10:34:26","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":194154,"visible":true,"origin":"","legend":"\u003cp\u003eReusability of yttrium-doped nickel aluminate.\u003c/p\u003e","description":"","filename":"floatimage14.png","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/b3492dac5704173c5dce2b28.png"},{"id":74858631,"identity":"d0e8809a-b154-416e-a115-9ac0aeda3ec3","added_by":"auto","created_at":"2025-01-27 16:12:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":4434981,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/dd088f18-bf23-43c2-b8fb-39965564126f.pdf"},{"id":68446155,"identity":"a4bade2f-0831-4964-8039-8bbf40232c1c","added_by":"auto","created_at":"2024-11-07 10:42:26","extension":"jpeg","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":2045748,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-5295270/v1/3f35cba11ad4b12e67125a53.jpeg"}],"financialInterests":"","formattedTitle":"Photocatalytic degradation of organic pollutants using yttrium and copper co-doped nickel aluminate","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe current situation of water pollution poses a significant threat to both human health and the environment (Moe and Rheingans, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2006\u003c/span\u003e). Improper sanitation poses numerous illnesses for the inhabitants. Various studies found that pollution is caused by human activities (Blaisdell et al., \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Water bodies containing organic impurities and minerals are due to anthropogenic activities (Warren-Vega et al., \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). The textile industry is one of the major producers of organic dye as a contaminant (Nasser Mohammed Hosny et al., 2023). Wastewater generated, even in smaller proportions, can affect the quality of water for aquatic organisms. The dyes, which are non-biodegradable, stay in the atmosphere for a longer duration and sometimes function as carcinogens. (Hassaan, Nemr and El, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Nasser Mohammed Hosny et al., 2023). The major issue affecting humans is respiratory difficulties due to the inhalation of dye particles. A condition called respiratory sensitization with symptoms like sneezing, asthma, watery eyes, coughing, etc., is noticed (Hassaan, Nemr and El, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). There are several types of dyes: cationic, anionic, and non-ionic; among them, cationic dyes are the most toxic. (Foroutan et al., \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Noreen et al., \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Salah Omer et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Cationic dyes are carcinogenic, hazardous, allergic dermatitis, teratogenic, etc. (Grassi et al., 2020; Salah Omer et al., \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2022\u003c/span\u003e)\u003c/p\u003e \u003cp\u003eCrystal violet (CV), a type of cationic dye, is largely used in the textile industry. It is used as a purple color in fabrics, silk, and printing ink (Au et al., \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e1979\u003c/span\u003e). Resident water bodies absorb this harmful water, which then turns into toxic. In the long term, it can cause damage to the cornea, skin rashes, problems in the digestive tract, and sometimes kidney failure (Jones and Falkinham III, 2003; Srinivas et al., \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Thomas and MacPhee, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e1984\u003c/span\u003e). It is extremely important to remove such a toxic dye from wastewater (Ahmad and Ejaz, \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Arab, El Kurdi and Patra, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Various methods for the removal of dye have been practiced, including coagulation, chemical oxidation, advanced oxidation process, filtration, reverse osmosis, adsorption, photocatalytic degradation, etc. (Ahmad and Ejaz, \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Photocatalytic degradation has been established as an eco-friendly, sustainable, and inexpensive method for the removal of dyes and converting them to H\u003csub\u003e2\u003c/sub\u003eO and CO\u003csub\u003e2\u003c/sub\u003e (P. Kowsalya, S. Uma Bharathi and M. Chamundeeswari, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Photocatalysis uses semiconductors along with a light source to produce species that are responsible for redox reactions (Nasser Mohammed Hosny et al., 2023).\u003c/p\u003e \u003cp\u003eThe synthesis of semiconductor nanomaterials can be achieved through various methods such as ball milling, auto-combustion, hydrothermal, chemical vapor synthesis, and sol-gel method. Sol-gel is a very simple technique that produces homogenous material with great structure and particle size (Luo et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). For photocatalysis, we need a material with a lower band gap, a large surface area, and a smaller particle size (Khalid et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2024\u003c/span\u003e; Luo et al., \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2017\u003c/span\u003e). Hence, we synthesize a spinel type of photocatalyst that has mechanical resistance, thermal stability, and hydrophobic. Nickel aluminate, a partially inverse spinel, is an efficient photocatalyst (Rohan Samkaria and Sharma, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2013\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eSeveral research studies exhibited compounds that could degrade crystal violet dye by photocatalytic degradation. A study (Singh et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) showed Fe doped La\u003csub\u003e0.7\u003c/sub\u003eSr\u003csub\u003e0.3\u003c/sub\u003eMnO\u003csub\u003e3\u003c/sub\u003e by the solid-state method with a degradation rate of 81.9% in their work. Whereas a study (S. Ben Ameur et al., \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) showed a degradation of crystal violet of 91.3% within 210 minutes. Strontium doped tin oxide was synthesized (Kaur et al., \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) via the sol-gel approach and found a degradation of 67.8%. Synthesis of nickel doped barium hexaferrite (G. Muhiuddin et al., \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) for photocatalytic degradation of crystal violet dye with an efficiency of 97%. Another study (S. Gouthamsri et al., \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) showed a degradation of 100% with the synthesized compound zirconium-doped zinc oxide via the same route followed by us sol-gel approach. Yttrium and zinc doping and co-doping on CeO\u003csub\u003e2\u003c/sub\u003e (Sharma \u0026amp; Pandey, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) by co-precipitation route and found the degradation percentage of CV to be 100% for both within a duration of 7 hours. For the present work, we have synthesized yttrium and copper, yttrium-co-doped nickel aluminate for photocatalytic degradation of crystal violet dye under ultraviolet light.\u003c/p\u003e"},{"header":"2. Experimental section","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 \u003cem\u003eMaterials \u0026amp; Methods\u003c/em\u003e\u003c/h2\u003e \u003cp\u003eNickel nitrate (Ni(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e.6H\u003csub\u003e2\u003c/sub\u003eO, 99.0%), Aluminium nitrate (Al(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e.9H\u003csub\u003e2\u003c/sub\u003eO, 98.0%), Yttrium nitrate (Y(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e.6H\u003csub\u003e2\u003c/sub\u003eO, 99.9%), Cupric nitrate trihydrate (Cu(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e.3H\u003csub\u003e2\u003c/sub\u003eO, 99.5%), and Citric acid (C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e8\u003c/sub\u003eO\u003csub\u003e7\u003c/sub\u003e, 99.5%) were used as starting materials for the synthesis of Nickel aluminate (NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e), Yttrium-doped Nickel Aluminate (NiAl\u003csub\u003e2\u0026thinsp;\u0026minus;\u0026thinsp;x\u003c/sub\u003eY\u003csub\u003ex\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e) and Yttrium-copper co-doped nickel aluminate. These chemicals are sourced from SD fine chemicals.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 \u003cem\u003eSynthesis of Nickel aluminate, Yttrium-doped and Yttrium-Copper co-doped nickel aluminate by sol-gel method\u003c/em\u003e\u003c/h2\u003e \u003cp\u003eThe catalyst was made by dissolving nickel nitrate in distilled water and then citric acid was added dropwise at 30\u0026deg;C for 30 minutes to the nickel nitrate solution and then stirred. In another beaker, aluminium nitrate, yttrium nitrate and copper nitrate were dissolved in water separately for the yttrium and copper doped nickel aluminate. These solutions were added to the nickel nitrate and citric acid mixture and heated at 60\u0026deg;C for 1 h. Then the temperature was increased to 80\u0026deg;C for 2 hours. Once the volume was reduced, the prepared gel was kept in the oven for drying at 120\u0026deg;C for 12 hours. It was ground well and kept in a muffle furnace for calcination at 800\u0026deg;C for 4 hours. The calcined material was ground, and the photocatalyst was formed (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). The same procedure was followed with and without copper and yttrium for copper and pristine nickel aluminate. The prepared undoped, yttrium-doped, and (Cu, Y) co-doped nickel aluminate was analyzed by various characterization techniques.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.5 \u003cem\u003eCharacterization\u003c/em\u003e\u003c/h2\u003e \u003cp\u003eThe crystal structure identification of the synthesized photocatalyst is executed by X-ray powder diffraction (XRD-BRUKER D8 Advanced) instrument with diffraction angle of 10\u0026ndash;70\u0026deg;. Optical properties were analyzed using the UV-Vis-NIR Spectrometer (UV-Visible Diffuse Reflectance) (JASCO V-670). Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray spectroscopy (EDAX) of the spinels was done with the ZESIS EVO18 SEM instrument. Photocatalysis was done using (JASCO-730) UV-Vis Spectrophotometer.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.6 \u003cem\u003ePhotocatalytic test\u003c/em\u003e\u003c/h2\u003e \u003cp\u003eThe photocatalytic degradation of crystal violet (10 ppm) was considered against a photocatalyst (10 mg) under irradiation with 250 W UV light for 120 minutes. Before UV light irradiation, sample was subjected to dark conditions for 30 minutes to attain adsorption-desorption equilibrium. 50 ml of 10 ppm Crystal Violet dye was poured into a quartz tube, and 3 ml sample aliquot was taken every 30 minutes until 120 minutes. Aliquot was characterized by UV-Vis (JASCO V-730) spectrometer within 200\u0026ndash;800 nm. The degradation was calculated using the below-given formula.\u003c/p\u003e \u003cp\u003e \u003cem\u003e% degradation =\u003c/em\u003e \u003cspan class=\"InlineEquation\"\u003e \u003cspan class=\"mathinline\"\u003e\\(\\:\\:\\:\\frac{{C}_{0}-{C}_{t}}{{C}_{0}}\\times\\:100\\)\u003c/span\u003e \u003c/span\u003e (1)\u003c/p\u003e \u003cp\u003eHere, \u003cem\u003eC\u003c/em\u003e\u003csub\u003e\u003cem\u003e0\u003c/em\u003e\u003c/sub\u003e is the initial concentration, the final concentration given by \u003cem\u003eC\u003c/em\u003e\u003csub\u003e\u003cem\u003et\u003c/em\u003e\u003c/sub\u003e at time t.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Result and Discussion","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.1 Structural Analysis\u003c/h2\u003e \u003cp\u003eThe pattern of XRD (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) shows the phase purity of the novel substituted spinel compound which includes increasing concentrations of yttrium and copper. There are no additional peaks due to the insertion of yttrium and copper into the lattice, suggesting the primary nickel-aluminate structure is retained. The peaks are indexed with ICDD No. 01-071-0965, and hence there is complete formation of NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e. The average crystallite size is calculated by the Debye-Scherrer formula by using the most intense peak (311). This provides information about the grain size and crystallinity of the spinel. The high intense peak (311) slightly shifted to lower angle due to the substitution of yttrium into the lattice. The shifting increases when copper is co-doped in yttrium substituted nickel aluminate. This could be due to the higher ionic radii copper and yttrium than nickel and aluminium (Anderson, Mehandru and Smialek, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e1985\u003c/span\u003e; Elakkiya, Abhishekram and Sumathi, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Also, the intensity of (440) peak increase due to co-doping of copper in the yttrium doped aluminate.\u003c/p\u003e \u003cp\u003eThe band gap of the nickel aluminate was calculated using the Tauc plot from the data obtained from UV-DRS. There is a significant decrease in the band gap in comparison to the parent nickel aluminate. The reduction signifies a shift in electronic structure and potentially enhanced photocatalytic activity. A smaller band gap facilitates the transition from the valence band to the conduction band and helps the reaction on the catalytic surface. This significant decrease in band gap implies the practical application of yttrium-doped and co-doped nickel aluminate in photocatalytic activity due to electronic transition.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAverage crystallite size and bandgap\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eNiAl\u003c/em\u003e\u003csub\u003e\u003cem\u003e2\u0026thinsp;\u0026minus;\u0026thinsp;x\u003c/em\u003e\u003c/sub\u003e\u003cem\u003eY\u003c/em\u003e\u003csub\u003e\u003cem\u003ex\u003c/em\u003e\u003c/sub\u003e\u003cem\u003eO\u003c/em\u003e\u003csub\u003e\u003cem\u003e4\u003c/em\u003e\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eAverage crystallite size (nm)\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eBand-Gap\u003c/em\u003e\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.271\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.221\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.213\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.21\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.189\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNAY07C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.546\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNAY10C\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e28.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.422\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003cdiv id=\"Equa\" class=\"Equation\"\u003e \u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:$$\u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Equ1\" class=\"Equation\"\u003e \u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:\\:D=\\:\\frac{k\\lambda\\:}{\\beta\\:cos\\theta\\:}$$\u003c/div\u003e \u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eWhere D is the average crystallite size, λ is wavelength, θ is Bragg\u0026rsquo;s angle, β is (FWHM) full-width at half maximum and k take a value of 0.9.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe Tauc-plot was used to find band gap energy which was calculated using Eq.\u0026nbsp;(\u003cspan refid=\"Equ2\" class=\"InternalRef\"\u003e3\u003c/span\u003e)\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:\\alpha\\:hv=A{(hv-{E}_{g})}^{1/2}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eHere \u003cem\u003eα\u003c/em\u003e is absorption coefficient, \u003cem\u003eh\u003c/em\u003e is Planck\u0026rsquo;s constant, \u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003eg\u003c/em\u003e\u003c/sub\u003e is optical band-gap \u003cem\u003eυ\u003c/em\u003e is photon frequency, and \u003cem\u003eA\u003c/em\u003e is a constant. Band Gap was calculated by extrapolating on the x-axis, which gives the absorption energy (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The band gap was calculated to be 2.271, 2.221, 2.213, 2.21, 2.189, 1.546, and 1.422 eV for x\u0026thinsp;=\u0026thinsp;0, x\u0026thinsp;=\u0026thinsp;0.03. x\u0026thinsp;=\u0026thinsp;0.05, x\u0026thinsp;=\u0026thinsp;0.07, x\u0026thinsp;=\u0026thinsp;0.1, NAY07C, and NAY10C, respectively. The decrease of the band gap helps in the larger mineralization of dye due to the generation of electron-hole pairs. Since the band gap for yttrium-doped nickel aluminate is in the Ultraviolet region, photocatalysis was conducted under UV light.\u003c/p\u003e \u003cp\u003eScanning electron microscopy (SEM) provides significant insights into the morphology of the synthesized compounds. SEM was recorded for selected compositions to understand the morphology Pristine compound showed heterogeneous shaped particles. In the case of yttrium doped compositions rock like structure with cavities were observed (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Field Emission Scanning Electron Microscopy images of copper and yttrium-co-doped nickel aluminate of Ni\u003csub\u003e0.9\u003c/sub\u003eCu\u003csub\u003e0.1\u003c/sub\u003eAl\u003csub\u003e1.9\u003c/sub\u003eY\u003csub\u003e0.1\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e showed slightly spherical shaped particles with agglomeration (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). Further, elemental confirmation was done through energy dispersive X-ray spectroscopy (EDAX), which confirmed the elements nickel, aluminum, yttrium, and oxygen, thus validating the composition of the spinels. These characterizations not only confirm the phase and morphology but also give a deeper understanding of their applications.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eXPS was used to understand the oxidation states of synthesized copper and yttrium co-doped nickel aluminate NAY10C (Ni\u003csub\u003e0.9\u003c/sub\u003eCu\u003csub\u003e0.1\u003c/sub\u003eAl\u003csub\u003e1.9\u003c/sub\u003eY\u003csub\u003e0.1\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e). X-ray photoelectron spectroscopy (XPS) shows the presence of nickel, aluminium, yttrium, copper, and oxygen in the spectra. Figure\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ea shows survey spectra of the co-doped sample. Nickel (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb) displays four peaks, among which the peaks at 855.80 eV and 873.26 eV represent Ni 2p\u003csub\u003e3/2\u003c/sub\u003e and Ni 2p\u003csub\u003e1/2\u003c/sub\u003e respectively (Prieto et al., \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). The peaks at 862.17 eV, and 880.13 eV depict the satellite peaks corresponding to Ni 2p (Elakkiya, Abhishekram and Sumathi, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Aluminium also shows four peaks in the XPS spectra at 68.27 eV, 74.01 eV, 75.00 eV (Kunde, Sehgal and Ganguli, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) and 77.28 eV which can be seen in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ec (Irie et al., \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Kozlica, Kokalj and Milošev, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Yttrium peaks were confirmed from the literature indicated in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ed. Peak at 157.39 eV illustrates Y 3d\u003csub\u003e5/2\u003c/sub\u003e (Dhilleswara Rao Vaddi et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) whereas 158.17 eV and 159.15 eV describe the Y 3d\u003csub\u003e3/2\u003c/sub\u003e state of Y\u003csup\u003e+\u0026thinsp;3\u003c/sup\u003e (Dhilleswara Rao Vaddi et al., \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; S. Muruganandam et al., \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Cu 2p showed five peaks, as seen in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ee. Binding energy 934.06 eV depicts 2p\u003csub\u003e3/2\u003c/sub\u003e of copper (El\u0026eacute;a Vernack et al., \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) and that of 941.77 eV confirmed by the resource (Amun Amri et al., 2013) whereas 954.68 eV shows the 2p\u003csub\u003e1/2\u003c/sub\u003e that is Cu\u003csup\u003e+\u0026thinsp;2\u003c/sup\u003e state and satellite peaks are illustrated at 943.67 eV, and 962.41 eV (Kirankumar, Mayank and Sumathi, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Oxygen 1s peaks are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ef. There are two peaks that are confirmed from the literature, which includes 530.86 eV and 533.72 eV of O-H hydroxyl group and O 1s, respectively (Hany, Khalaf and Ibrahim M.A. Mohamed, 2024).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Photocatalytic activity\u003c/h2\u003e \u003cp\u003eThe photocatalytic activity of nickel aluminate and nickel aluminate doped with yttrium and copper was taken into consideration. Catalytic activity against the organic pollutant crystal violet was demonstrated under UV light. Degradation efficiency was calculated using Eq.\u0026nbsp;1.\u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e3.2.1 Effect of insertion of metal ion into the lattice\u003c/h2\u003e \u003cp\u003ePhotodegradation was performed using yttrium-doped nickel aluminate NiAl\u003csub\u003e1\u0026thinsp;\u0026minus;\u0026thinsp;x\u003c/sub\u003eY\u003csub\u003ex\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e (x\u0026thinsp;=\u0026thinsp;0, 0.03, 0.05, 0.07, and 0.1). 250 W UV lamp was used to irradiate 50 ml of 10 ppm crystal violet dye with 10 mg of the catalyst. Before irradiation the mixture was kept under dark condition with stirring for 30 minutes. The sample was withdrawn in an interval of 30 minutes and UV-Vis spectrum was recorded after centrifugation. After 120 minutes of photodegradation, the parent nickel aluminate exhibited 83.54% degradation efficiency. As illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e, the highest yttrium concentration (x\u0026thinsp;=\u0026thinsp;0.1) demonstrated a remarkable degradation rate of 97.40% for the crystal violet dye, indicating its superior catalytic efficiency. The catalytic activity was increased with increased in the dopant concentration. The high level of degradation suggests that yttrium-doped nickel aluminate is a more effective catalyst compared to its undoped counterpart. The enhanced photocatalytic performance is likely due to the reduction in band gap, which facilitates better absorption of UV light. Consequently, the mineralization of the crystal violet dye under UV light is significantly improved.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhotocatalytic degradation of crystal violet.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNiAl\u003csub\u003e2\u0026thinsp;\u0026minus;\u0026thinsp;x\u003c/sub\u003eY\u003csub\u003ex\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDegradation percentage\u003c/p\u003e \u003cp\u003e(%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e83.54\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e88.21\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e92.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e93.78\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ex\u0026thinsp;=\u0026thinsp;0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e97.40\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section3\"\u003e \u003ch2\u003e3.2.2 Effect of catalyst dosage\u003c/h2\u003e \u003cp\u003eThe best dopant concentration was identified and the photocatalytic activity of NiAl\u003csub\u003e0.9\u003c/sub\u003eY\u003csub\u003e0.1\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e was carried out using 10 ppm of CV dye with 5 mg, 10 mg, and 20 mg of catalyst. The degradation percentage observed with a 10 mg catalyst was 97.39%, but 5 mg of the catalyst yielded a degradation of 95.96%. The degradation efficiency 97.76% was recorded with a 20 mg of the catalyst. Due to the minimal differences in performance between the 10 mg and 20 mg catalysts, the 10 mg dosage was selected for further optimization. (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e). This choice balances high efficiency with practical considerations, such as cost and ease of handling. As a result, using 10 mg of catalyst strikes a balance between performance and feasibility for ongoing studies.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section3\"\u003e \u003ch2\u003e3.2.3 Effect of concentration of crystal violet dye\u003c/h2\u003e \u003cp\u003eTo investigate the impact of varying dye concentrations on degradation efficiency, solutions with concentrations of 25 ppm and 50 ppm were prepared and subjected to UV irradiation using 10 mg of NiAl\u003csub\u003e0.9\u003c/sub\u003eY\u003csub\u003e0.1\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e. The results indicated that the 25 ppm dye solution achieved a degradation rate of 89.61%. In contrast, the 50 ppm dye solution exhibited a significantly lower degradation rate of 54%. This reduction in degradation efficiency with increasing dye concentration suggests that higher pollutant levels reduce the photocatalyst's effectiveness. The decreased degradation at higher concentrations is likely due to the increased number of dye molecules, which may lead to competitive adsorption on the catalyst surface and reduce the availability of active sites (Ajithkumar, Mohana and Sumathi, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Consequently, this trend underscores the challenge of achieving high degradation rates in solutions with elevated pollutant concentrations. (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e). The findings highlight the need for optimizing catalyst dosage and concentration to enhance the photocatalytic performance.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section3\"\u003e \u003ch2\u003e3.2.4 Effect of pH\u003c/h2\u003e \u003cp\u003eThe effect of pH plays a vital role in the degradation of dyes; it can either increase or decrease the activity of the catalyst. pH was adjusted to 4, 7 and 11 using HCl and NaOH respectively, using a pH meter. From Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003e we can understand that with the increase in pH, the activity was increased. pH 4 indicated an 81% deterioration as exterior sites became positively charged. At pH\u0026thinsp;=\u0026thinsp;7 resulted in 84% degradation, but pH\u0026thinsp;=\u0026thinsp;11 resulted in a significant increase in photocatalytic activity of 96%, this is considered the optimum degradation state due to an increase in OH\u003csup\u003e\u0026minus;\u003c/sup\u003eions. We can see that there has been a rise in OH\u003csup\u003e\u0026minus;\u003c/sup\u003e, which increases efficiency (Ajithkumar, Mohana and Sumathi, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2019\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section3\"\u003e \u003ch2\u003e3.2.5 Effect of scavengers\u003c/h2\u003e \u003cp\u003eThe key role in photocatalysis is the production of reactive species including holes (h\u003csup\u003e+\u003c/sup\u003e), hydroxide radical (OH.), electron (e\u003csup\u003e\u0026minus;\u003c/sup\u003e), and superoxide radical (O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e.), which helps in breaking pollutant into smaller fragments. It is of foremost importance to understand the mechanism of photocatalytic degradation of CV against the synthesized photocatalyst. Initially, 10 ppm of CV was stirred in a dark condition, after which 1mM of scavengers were added to this solution and irradiated with 250 W UV light. Aliquots of the sample were taken for every 30 minutes and continued to 2 hours. Addition of Isopropyl alcohol (OH.) and EDTA (h\u003csup\u003e+\u003c/sup\u003e) showed not much change in degradation, suggesting that OH. and h\u003csup\u003e+\u003c/sup\u003e was not involved in the reaction. The degradation efficiency of crystal violet was observed to decrease slightly in the presence of benzoquinone (O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e.) and silver nitrate (e\u003csup\u003e\u0026minus;\u003c/sup\u003e) in 120 minutes. The reduction in efficiency highlights that O\u003csub\u003e2\u003c/sub\u003e\u003csup\u003e\u0026minus;\u003c/sup\u003e. radicals and electrons (e\u003csup\u003e\u0026minus;\u003c/sup\u003e) play a significant role in the photocatalytic degradation process. (Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e11\u003c/span\u003e). The presence of these scavengers indicates that both superoxide radicals and electrons are crucial for the effective breakdown of the dye. Their interaction with the crystal violet molecules facilitates the degradation mechanism.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section3\"\u003e \u003ch2\u003e3.2.7 Optimized condition for copper yttrium co-doped nickel aluminate\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eUsing the optimized conditions such as 10 ppm, 10 mg of the catalyst, pH\u0026thinsp;=\u0026thinsp;11 (alkaline condition) the photocatalytic activity of copper and yttrium doped nickel aluminate NAY10C (Ni\u003csub\u003e0.9\u003c/sub\u003eCu\u003csub\u003e0.1\u003c/sub\u003eAl\u003csub\u003e1.9\u003c/sub\u003eY\u003csub\u003e0.1\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e) was carried out. Under these conditions, the photocatalysis was conducted under 250 W UV light. The co-doped catalyst NAY10C achieved a remarkable degradation rate of 96.32% in 90 min itself, surpassing the performance of yttrium-doped nickel aluminate (Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e12\u003c/span\u003e). This suggests that the co-doped catalyst offers superior photocatalytic activity under the optimized conditions.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section3\"\u003e \u003ch2\u003e3.2.6 Recyclability studies\u003c/h2\u003e \u003cp\u003eTo understand the stability of the prepared photocatalyst, it is vital to carry out reusability studies. 10 mg of (x\u0026thinsp;=\u0026thinsp;0.1) of yttrium-doped nickel aluminate was studied against 10 ppm of crystal violet dye. The photocatalysis was carried out for 120 minutes under a 250 W UV lamp (Fig.\u0026nbsp;\u003cspan refid=\"Fig13\" class=\"InternalRef\"\u003e13\u003c/span\u003e). After 1st cycle the photocatalyst was washed with ethanol (C\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH) for desorption and it was washed with distilled water. The washed catalyst was dried and went through another cycle. Degradation after 1st cycle was found to be 98.65%. The percentage degradation in the second cycle was 97.19%, and in the third cycle, it was 95%. This decrease in degradation efficiency demonstrates the photocatalyst's stability and reusability over multiple cycles. The minimal reduction in performance indicates that the prepared catalyst maintains its high efficiency even after repeated use. These results highlight the robustness and durability of the catalyst in photocatalytic applications.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003e3.6 Possible mechanism for degradation of CV\u003c/h2\u003e \u003cp\u003eThe photocatalytic degradation mechanism involving yttrium-doped nickel aluminate begins with the absorption of photons (hν), leading to the excitation of electrons (e\u003csup\u003e\u0026minus;\u003c/sup\u003e) from the valence band (VB) to the conduction band (CB), resulting in the formation of electron-hole pairs (e\u003csup\u003e\u0026minus;\u003c/sup\u003e (CB) and h\u003csup\u003e+\u003c/sup\u003e (VB)). The excited electron in the conduction band interacts with nearby oxygen molecules. This interaction leads to the formation of superoxide radicals (.O₂⁻). The superoxide radicals subsequently react with protons (H⁺), facilitating a chemical transformation. This reaction results in the production of hydrogen peroxide (H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e), which is a key intermediate in oxidation processes. Hydrogen peroxide undergoes reduction, in the presence of catalyst, breaking down into hydroxyl radicals. These hydroxyl radicals (OH\u0026bull;) are highly reactive species that contribute to further oxidative reactions, significantly influencing the degradation of organic compounds. In the final stage, the superoxide radicals (.O₂⁻) directly interact with the crystal violet dye (CV). These reactions lead to the breakdown of the dye molecules into smaller degradation products, ultimately resulting in the decolorization and mineralization of the dye. This series of reactions highlights the role of superoxide radicals and hydroxyl radicals in the photocatalytic degradation process (Singh et al., \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2022\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eYttrium-doped and copper-yttrium co-doped nickel aluminate was synthesized via a very simple sol-gel method with a calcination temperature of 800\u0026deg;C for 4 hours. SEM results showed an agglomerated structure in the samples. Parent nickel aluminate, along with doped and co-doped samples were analyzed by XRD, UV-DRS, SEM-EDAX, XPS, and FE-SEM. Insertion of yttrium and copper decreased the band gap, and we can see a shift in peaks towards the lower angle in the XRD. The cationic dye crystal violet is used to understand the photocatalytic activity of the prepared photocatalyst. Parameters including pH, catalyst dosage, and dye concentration were analyzed. With increasing pH, there is greater degradation efficiency in doped and co-doped samples. Based on the reactions performed, it is evident that both yttrium-doped and co-doped catalysts exhibit promising photocatalytic efficiency. We can conclude that both yttrium-doped and copper co-doped samples hold significant potential as viable catalysts for photodegradation applications.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u003c/strong\u003e We would like to thank the VIT university management for providing all necessary facilities and permission for research and to carry out the experiments.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval-\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate-\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish-\u0026nbsp;\u003c/strong\u003eWe give our consent to publish the paper in this journal.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement-\u0026nbsp;\u003c/strong\u003eAll data analyzed during the study has been submitted in this manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors Contributions\u003c/strong\u003e- Material synthesis, formal analysis, methodology, and writing original draft was conducted by Anju Nair. Review and writing were made by Ancy Kurian and Abima S. Conceptualization, Validation, and Supervision was made by Shanmugam Sumathi.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e- No external funding is involved.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e- The authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAhmad R, Ejaz MO (2023) Efficient adsorption of crystal violet (CV) dye onto benign chitosan-modified l-cysteine/bentonite (CS-Cys/Bent) bionanocomposite: Synthesis, characterization and experimental studies. Dyes Pigm [online] 216:111305. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.dyepig.2023.111305\u003c/span\u003e\u003cspan address=\"10.1016/j.dyepig.2023.111305\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAjithkumar P, Mohana S, Sumathi S (2019) Synthesis, characterization, optical and photocatalytic activity of yttrium and copper co-doped zinc ferrite under visible light. J Mater Sci: Mater Electron 31(2):1168\u0026ndash;1182. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10854-019-02628-8\u003c/span\u003e\u003cspan address=\"10.1007/s10854-019-02628-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAmun Amri, Duan X, Yin C, Zhong Tao Jiang M, Mahbubur Rahman, Pryor T (2013) Solar absorptance of copper\u0026ndash;cobalt oxide thin film coatings with nano-size, grain-like morphology: Optimization and synchrotron radiation XPS studies. Appl Surf Sci 275:127\u0026ndash;135. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.apsusc.2013.01.081\u003c/span\u003e\u003cspan address=\"10.1016/j.apsusc.2013.01.081\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnderson AB, Mehandru SP, Smialek JL (1985) Dopant Effect of Yttrium and the Growth and Adherence of Alumina on Nickel-Aluminum Alloys. J Electrochem Soc 132(7):1695\u0026ndash;1701. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1149/1.2114193\u003c/span\u003e\u003cspan address=\"10.1149/1.2114193\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArab C, El Kurdi R, Patra D (2022) Zinc curcumin oxide nanoparticles for enhanced adsorption of Congo red: kinetics and adsorption isotherms study. Mater Today Chem 23:100701. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.mtchem.2021.100701\u003c/span\u003e\u003cspan address=\"10.1016/j.mtchem.2021.100701\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAu W, Butler MA, Bloom SE, Matney TS (1979) Further study of the genetic toxicity of gentian violet. Mutat Research/Genetic Toxicol 66(2):103\u0026ndash;112. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/0165-1218(79)90054-5\u003c/span\u003e\u003cspan address=\"10.1016/0165-1218(79)90054-5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBlaisdell J, Turyk ME, Almberg KS, Jones RM, Stayner LT (2019) Prenatal exposure to nitrate in drinking water and the risk of congenital anomalies. Environ Res 176:108553. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.envres.2019.108553\u003c/span\u003e\u003cspan address=\"10.1016/j.envres.2019.108553\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVaddi DR, Vinukonda K, Patnala RK, Kanithi Y, Gurugubelli TR, Bae J, Koutavarapu R, Lee D-Y, Shim J (2023) Effect of yttrium doping on the crystal structure, optical, and photocatalytic properties of hydrothermally synthesized ZnO nanorods. Mater Sci Engineering: B 296:116664\u0026ndash;116664. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.mseb.2023.116664\u003c/span\u003e\u003cspan address=\"10.1016/j.mseb.2023.116664\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEl\u0026eacute;a Vernack S, Zanna, Seyeux A, Costa D, Chiter F, Tingaut P, Marcus P (2023) ToF-SIMS, XPS and DFT study of the adsorption of 2-mercaptobenzothiazole on copper in neutral aqueous solution and corrosion protection in chloride solution. Corros Sci 210:110854\u0026ndash;110854. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.corsci.2022.110854\u003c/span\u003e\u003cspan address=\"10.1016/j.corsci.2022.110854\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eForoutan R, Mohammadi R, Sohrabi N, Sahebi S, Farjadfard S, Esvandi Z, Ramavandi B (2020) Calcined alluvium of agricultural streams as a recyclable and cleaning tool for cationic dye removal from aqueous media. Environ Technol Innov 17:100530. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.eti.2019.100530\u003c/span\u003e\u003cspan address=\"10.1016/j.eti.2019.100530\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMuhiuddin G, Bibi I, Nazeer Z, Majid F, Kamal S, Kausar A, Raza Q, Alwadai N, Ezzine S, Iqbal M (2023) Synthesis of Ni doped barium hexaferrite by microemulsion route to enhance the visible light-driven photocatalytic degradation of crystal violet dye. Ceram Int 49(3):4342\u0026ndash;4355. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.ceramint.2022.09.319\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2022.09.319\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGrassi P, Drumm FC, Spannemberg SS, jordana georgin, Tonato D, Mazutti M, Gon\u0026ccedil;alves Jana\u0026iacute;na, Leandro M Guilherme Luiz Dotto and S\u0026eacute;rgio Luiz Jahn (2020) Solid wastes from the enzyme production as a potential biosorbent to treat colored effluents containing crystal violet dye. Environ Sci Pollut Res, 27(10):10484\u0026ndash;10494. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s11356-020-07664-0\u003c/span\u003e\u003cspan address=\"10.1007/s11356-020-07664-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHany, Khalaf MM, Ibrahim MA, Mohamed (2024) XPS analysis, voltammetric, and impedance characteristics of novel heterogeneous biphosphates based on Cu/Ni for tri(ammonium) phosphate oxidation: A new direction for material processing in fuel technology. Fuel 356:129618\u0026ndash;129618. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.fuel.2023.129618\u003c/span\u003e\u003cspan address=\"10.1016/j.fuel.2023.129618\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHassaan M, Nemr A, El A (2017) Health and Environmental Impacts of Dyes: Mini Review. Nemr Health Environ Impacts Dyes: Mini Rev Am J Environ Sci Eng [online] 1(3):64\u0026ndash;67. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.11648/j.ajese.20170103.11\u003c/span\u003e\u003cspan address=\"10.11648/j.ajese.20170103.11\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIrie Y, Maruo Y, Kataoka N, Tanaka H, Kinoshita K, Kishida S (2017) AFM and XPS study from surfaces of native oxide/Al-metal. Procedia Eng 216:182\u0026ndash;189. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.proeng.2018.04.001\u003c/span\u003e\u003cspan address=\"10.1016/j.proeng.2018.04.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJones JJ, Falkinham III, J.O (2003) Decolorization of Malachite Green and Crystal Violet by Waterborne Pathogenic Mycobacteria. Antimicrob Agents Chemother [online] 47(7):2323\u0026ndash;2326. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1128/aac.47.7.2323-2326.2003\u003c/span\u003e\u003cspan address=\"10.1128/aac.47.7.2323-2326.2003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKaur M, Prasher D, Dhiman V, Murugesan P, Ghosh D, Sharma R (2023) Green energy induced photocatalytic decomposition of methylene blue and crystal violet dyes by strontium doped tin oxide nanoparticles and its antibacterial activity. Physica B 661:414924\u0026ndash;414924. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.physb.2023.414924\u003c/span\u003e\u003cspan address=\"10.1016/j.physb.2023.414924\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhalid H, Haq Aul, Zahoor AF, Irfan A, Zaki A (2024) An investigation of Ca-doped MgO nanoparticles for the improved catalytic degradation of thiamethoxam pesticide subjected to visible light irradiation. Sci Rep 14(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-024-51738-9\u003c/span\u003e\u003cspan address=\"10.1038/s41598-024-51738-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKirankumar VS, Mayank N, Sumathi S (2019) Photocatalytic performance of cerium doped copper aluminate nanoparticles under visible light irradiation. J Taiwan Inst Chem Eng 95:602\u0026ndash;615. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jtice.2018.09.020\u003c/span\u003e\u003cspan address=\"10.1016/j.jtice.2018.09.020\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKozlica DK, Kokalj A, Milošev I (2021) Synergistic effect of 2-mercaptobenzimidazole and octylphosphonic acid as corrosion inhibitors for copper and aluminium \u0026ndash; An electrochemical, XPS, FTIR and DFT study. Corros Sci 182:109082\u0026ndash;109082. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.corsci.2020.109082\u003c/span\u003e\u003cspan address=\"10.1016/j.corsci.2020.109082\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKunde GB, Sehgal B, Ganguli AK (2021) Modified EISA synthesis of NiAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003e/MWCNT composite mesoporous free-standing film as a potential electrochemical capacitor material. J Alloys Compd 856:158019\u0026ndash;158019. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jallcom.2020.158019\u003c/span\u003e\u003cspan address=\"10.1016/j.jallcom.2020.158019\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuo J, Wang S, Liu W, Tian C, Wu J, Zu X, Zhou W, Yuan X, Xiang X (2017) Influence of different aluminum salts on the photocatalytic properties of Al doped TiO2 nanoparticles towards the degradation of AO7 dye. Sci Rep 7(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-017-08216-2\u003c/span\u003e\u003cspan address=\"10.1038/s41598-017-08216-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMoe CL, Rheingans RD (2006) Global challenges in water, sanitation and health. J Water Health 4(S1):41\u0026ndash;57. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2166/wh.2006.0043\u003c/span\u003e\u003cspan address=\"10.2166/wh.2006.0043\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGomaa NMH, Elmahgary I, M.G. and, Ibrahim M (2023) ZnO doped C: Facile synthesis, characterization and photocatalytic degradation of dyes. Sci Rep 13(1). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41598-023-41106-4\u003c/span\u003e\u003cspan address=\"10.1038/s41598-023-41106-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNoreen S, Tahira M, Ghamkhar M, Hafiz I, Bhatti HN, Nadeem R, Murtaza MA, Yaseen M, Sheikh AA, Naseem Z, Younas F (2021) Treatment of textile wastewater containing acid dye using novel polymeric graphene oxide nanocomposites (GO/PAN,GO/PPy, GO/PSty). J Mater Res Technol 14:25\u0026ndash;35. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jmrt.2021.06.007\u003c/span\u003e\u003cspan address=\"10.1016/j.jmrt.2021.06.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKowsalya P, Uma Bharathi S, Chamundeeswari M (2023) Photocatalytic treatment of textile effluents by biosynthesized photo-smart catalyst: an eco-friendly and cost-effective approach. \u003cem\u003eEnvironment, Development and Sustainability\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10668-023-03172-6\u003c/span\u003e\u003cspan address=\"10.1007/s10668-023-03172-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePrieto P, Nistor V, Nouneh K, Oyama M, Abd-Lefdil M, D\u0026iacute;az R (2012) XPS study of silver, nickel and bimetallic silver\u0026ndash;nickel nanoparticles prepared by seed-mediated growth. Appl Surf Sci 258(22):8807\u0026ndash;8813. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.apsusc.2012.05.095\u003c/span\u003e\u003cspan address=\"10.1016/j.apsusc.2012.05.095\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRohan Samkaria, Sharma V (2013) Effect of rare earth yttrium substitution on the structural, dielectric and electrical properties of nanosized nickel aluminate. Mater Sci Engineering: B 178(20):1410\u0026ndash;1415. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.mseb.2013.08.017\u003c/span\u003e\u003cspan address=\"10.1016/j.mseb.2013.08.017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBen Ameur S, BelHadjltaief H, Duponchel B, Leroy G, Amlouk M, Hajer Guermazi and Samir Guermazi (2019) Enhanced photocatalytic activity against crystal violet dye of Co and In doped ZnO thin films grown on PEI flexible substrate under UV and sunlight irradiations. Heliyon 5(6):e01912\u0026ndash;e01912. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.heliyon.2019.e01912\u003c/span\u003e\u003cspan address=\"10.1016/j.heliyon.2019.e01912\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGouthamsri S, Malla Ramanaiah K, Basavaiah, Jaya Rao K (2023) Zr-doped ZnO nanohybrid via Glycine mediated sol-gel approach as benign supporter for degradation of Crystal violet and antibacterial performance. Results Chem 6:101080\u0026ndash;101080. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.rechem.2023.101080\u003c/span\u003e\u003cspan address=\"10.1016/j.rechem.2023.101080\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMuruganandam S, Kannan S, Anishia SR, Krishnan P (2023) Electrochemical performance of Yttrium doped SnO\u003csub\u003e2\u003c/sub\u003e\u0026ndash;NiO nanocomposite for energy storage applications. J Phys Chem Solids 179:111420\u0026ndash;111420. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jpcs.2023.111420\u003c/span\u003e\u003cspan address=\"10.1016/j.jpcs.2023.111420\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003esalah omer A, Naeem AE, Abd-Elhamid G, Farahat AIOM, El-Bardan OA, Soliman AMA, H. and, Nayl AA (2022) Adsorption of crystal violet and methylene blue dyes using a cellulose-based adsorbent from sugarcane bagasse: characterization, kinetic and isotherm studies. J Mater Res Technol 19:3241\u0026ndash;3254. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jmrt.2022.06.045\u003c/span\u003e\u003cspan address=\"10.1016/j.jmrt.2022.06.045\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSharma PK, Pandey OP (2022) Enhanced photocatalytic activity with metal ion doping and co-doping in CeO\u003csub\u003e2\u003c/sub\u003e nanoparticles. Solid State Sci 126:106846. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.solidstatesciences.2022.106846\u003c/span\u003e\u003cspan address=\"10.1016/j.solidstatesciences.2022.106846\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSingh B, Singh P, Siddiqui S, Singh D, Gupta M (2022) Wastewater treatment using Fe-doped perovskite manganites by photocatalytic degradation of methyl orange, crystal violet and indigo, carmine dyes in tungsten bulb/sunlight. J Rare Earths 1311\u0026ndash;1322. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jre.2022.09.010\u003c/span\u003e\u003cspan address=\"10.1016/j.jre.2022.09.010\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSrinivas S, Durga Abhishay A, Kusuma A, Gowthami Y, Gummadi Sowgandh and Meena Vangalapati (2023) Optimization, kinetics and thermodynamics for the removal of crystal violet dye using synthesized FeNPs from Carica papaya leaves extract. \u003cem\u003eMaterials Today: Proceedings\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.matpr.2023.04.035\u003c/span\u003e\u003cspan address=\"10.1016/j.matpr.2023.04.035\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThomas SM, MacPhee DG (1984) Crystal violet: a direct-acting frameshift mutagen whose mutagenicity is enhanced by mammalian metabolism. Mutat Res Lett [online] 140(4):165\u0026ndash;167. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/0165-7992(84)90071-x\u003c/span\u003e\u003cspan address=\"10.1016/0165-7992(84)90071-x\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eElakkiya V, Abhishekram. R, Sumathi S (2019) Copper doped nickel aluminate: Synthesis, characterisation, optical and colour properties. Chin J Chem Eng 27(10):2596\u0026ndash;2605. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.cjche.2019.01.008\u003c/span\u003e\u003cspan address=\"10.1016/j.cjche.2019.01.008\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWarren-Vega WM, Campos-Rodr\u0026iacute;guez A, Z\u0026aacute;rate-Guzm\u0026aacute;n AI, Romero-Cano LA (2023) A Current Review of Water Pollutants in American Continent: Trends and Perspectives in Detection, Health Risks, and Treatment Technologies. Int J Environ Res Public Health [online] 20(5):4499\u0026ndash;4499. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/ijerph20054499\u003c/span\u003e\u003cspan address=\"10.3390/ijerph20054499\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"environmental-science-and-pollution-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"espr","sideBox":"Learn more about [Environmental Science and Pollution Research](https://www.springer.com/journal/11356)","snPcode":"11356","submissionUrl":"https://submission.nature.com/new-submission/11356/3","title":"Environmental Science and Pollution Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Nickel aluminate, yttrium copper co-doped nickel aluminate, photocatalytic activity, crystal violet","lastPublishedDoi":"10.21203/rs.3.rs-5295270/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5295270/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSpinel nickel aluminate was synthesized using the sol-gel process and\u0026nbsp;citric acid as a capping agent. Parent nickel aluminate, yttrium-doped nickel aluminate, and yttrium-copper co-doped nickel aluminate were synthesized and calcined at 800 °C for 4 hours. The synthesized spinels were used to enhance photocatalytic activity and can convert harmful organic dyes into simpler, less harmful molecules like CO\u003csub\u003e2\u003c/sub\u003e and H\u003csub\u003e2\u003c/sub\u003eO. The synthesized nanoparticles were characterized by various techniques, including XRD, UV-DRS, XPS, and SEM-EDAX. X-ray diffraction analysis helped in understanding the purity of phases, the lattice parameter, and the determination of average crystallite size. UV-DRS gave vital information about electronic property, i.e., band gap, by utilizing the Tauc plot method. The morphology of the nanoparticles was characterized by SEM (scanning electron microscopy), whereas elemental confirmation in the nickel aluminate lattice was carried out by EDAX. XPS provided information on the oxidation states of the ions present in the spinels. Photocatalysis was conducted against the organic dye crystal violet. Yttrium-doped nickel aluminate exhibited a higher photocatalytic activity in comparison to undoped nickel aluminate. This suggested improved activity in photocatalysis due to the insertion of yttrium into the lattice. Parameters such as pH, the effect of catalyst dosage, and the effect of concentration of dye were analyzed.\u003c/p\u003e","manuscriptTitle":"Photocatalytic degradation of organic pollutants using yttrium and copper co-doped nickel aluminate","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-11-07 10:26:21","doi":"10.21203/rs.3.rs-5295270/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revision","date":"2024-11-22T07:09:58+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2024-10-29T04:09:06+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2024-10-28T19:19:25+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"Environmental Science and Pollution Research","date":"2024-10-28T13:36:36+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2024-10-25T04:19:01+00:00","index":"","fulltext":""},{"type":"submitted","content":"Environmental Science and Pollution Research","date":"2024-10-24T07:55:28+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"environmental-science-and-pollution-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"espr","sideBox":"Learn more about [Environmental Science and Pollution Research](https://www.springer.com/journal/11356)","snPcode":"11356","submissionUrl":"https://submission.nature.com/new-submission/11356/3","title":"Environmental Science and Pollution Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a29b900d-7592-4288-b477-ed7be64ac904","owner":[],"postedDate":"November 7th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-01-27T16:06:45+00:00","versionOfRecord":{"articleIdentity":"rs-5295270","link":"https://doi.org/10.1007/s11356-025-35913-7","journal":{"identity":"environmental-science-and-pollution-research","isVorOnly":false,"title":"Environmental Science and Pollution Research"},"publishedOn":"2025-01-20 15:57:50","publishedOnDateReadable":"January 20th, 2025"},"versionCreatedAt":"2024-11-07 10:26:21","video":"","vorDoi":"10.1007/s11356-025-35913-7","vorDoiUrl":"https://doi.org/10.1007/s11356-025-35913-7","workflowStages":[]},"version":"v1","identity":"rs-5295270","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5295270","identity":"rs-5295270","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}