Biosynthesis of Cu-doped TiO2 nanoparticles with Aloe vera extract for air purification and disinfection

Biosynthesis of Cu-doped TiO2 nanoparticles with Aloe vera extract for air purification and disinfection | 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 Biosynthesis of Cu-doped TiO 2 nanoparticles with Aloe vera extract for air purification and disinfection Niloofar Arefipour, Hassan Koohestani, Hedayat Gholami This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5925522/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The use of plant extracts for the synthesis of nanoparticles has attracted much attention due to its simplicity, environmental friendliness, and cost-effectiveness. This study synthesized titanium dioxide (TiO2) nanoparticles using Aloe vera and Salvia extracts. Its doping with copper was also investigated to reduce the electron/hole pair recombination rate and improve the photocatalytic activity of titania. Biosynthesized titania (TiO 2 ) nanoparticles were characterized by X-ray diffraction (XRD), Diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). XRD reported the formation of crystals with sizes of 4–7 nm by the Scherrer method and 5–27 nm by the Williamson-Hall method. FE-SEM and TEM analysis showed the formation of spherical particles. Spectroscopic results showed that adding copper element reduced the band gap energy from 3.10 eV to 2.89 eV. These results increased the removal efficiency of suspended particles, Escherichia coli bacteria, and coronavirus by titania nanoparticles. Therefore, Cu-TiO 2 nanoparticles biosynthesized with Aloe vera extract showed increased photocatalytic and antibacterial activity that can be used for air purification. TiO2 Biosynthesis Copper Doping Air Purification Aloe Vera Extract Sage Extract Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction As the need for a clean environment grows, so must pollutant removal standards. Thus, new methods for purifying water and air are increasingly important. Titania (TiO 2 ) is widely used as a photocatalyst for degrading toxic organic compounds in the aqueous and gas phases [ 1 , 2 ]. Titania nanoparticles can react with OH and O 2 , providing oxygen and hydroxyl free radicals for oxidation-reduction reactions. Due to the increased surface area of ​​the nanoparticles, the surface area for interaction with pathogenic bacteria increases, making them suitable as antimicrobial agents. The small size of the particles enables them to easily enter the surface of bacteria and cause damage to them [ 3 , 4 ]. Titania has three different phases: anatase, rutile, and brookite. Titania has a wide energy band gap of 3-3.2 eV that is excited only by UV light with wavelengths below 400 nm. In addition, only a small fraction (less than 5%) of the solar spectrum at the Earth’s surface is UV light [ 5 , 6 ]. Therefore, considerable efforts have been made in recent years to improve the catalytic activity of titania using visible light by modifying its properties, such as specific surface area and energy band gap (E g ). Doping titania with nonmetallic (C, N, S, I) and metallic (Cr, Mn, Fe, Ni) ions is a practical and attractive way to reduce the band gap and thus extend its photocatalytic response to the visible region of the solar spectrum. Adding a dopant changes the electronic structure of titania, such that by increasing the valence band level and/or decreasing the conduction band energy, its band gap decreases, and its absorption ability shifts to the visible region [ 7 – 9 ]. Several methods, such as sol-gel [ 10 , 11 ], co-precipitation [ 1 ], liquid phase precipitation [ 12 ], and hydrothermal [ 13 ] have been used to synthesize titania nanoparticles. In comparison, biological synthesis is an environmentally friendly protocol that involves the use of various parts and types of biogenic natural sources such as bacteria (intracellular and extracellular), fungi, yeasts, viruses, and various parts of green plants (flowers, stems, roots, leaves, and fruits). Biological sources, both as reducing agents and stabilizing agents, can prevent the overall growth of nanoparticles during the synthesis process. In addition, titania nanoparticles obtained by this method are safe, non-toxic, environmentally friendly, and require minimal energy [ 3 , 5 , 14 ]. Due to the diversity of plants, the synthesis of nanoparticles from plants is an interesting topic worldwide, as different plant species are rapidly being investigated and used to synthesize nanoparticles. Studies for the biosynthesis of titania nanoparticles using plants such as Azadirachta indica, Nyctanthes tristis-arbor, Hibiscus flower, and Catharanthus roseus with leaves, fruits, bark, flowers, etc., have been reported [ 15 – 18 ]. Sage and Aloe vera are among the oldest medicinal plants, with antimicrobial properties and the ability to purify ambient air. Carboxylic acids, terpenoids, flavonoids, and proteins present in Aloe vera leaf extract help form titania nanoparticles and act as a capping agent and reducing agent in the biosynthesis process [ 19 ]. For this reason, Sage and Aloe vera were used in this study to synthesize titania and copper-doped titania. Various analyses then characterized the nanoparticles and evaluated their performance in air purification. 2. Materials and Methods 2 − 1. Materials For this work, titanium tetraisopropoxide (99.9%) (C 12 H 28 O 4 Ti) was purchased from Dae Jung, and copper sulfate pentahydrate (99.9%) was purchased from Sigma Aldrich. Aloe vera and Sage were obtained from different regions of Iran. 2–2. Extract preparation To prepare the extract, a certain amount of plant (50 g fresh Aloe vera leaves, 25 g dried Sage plant) was added to 250 ml deionized water and stirred at 90°C for 2 h. Finally, the resulting mixture was filtered using filter paper to remove the plant residue. 2–3. Green Synthesis of Titania Nanoparticles A 0.1 M titanium solution was prepared by adding 2.96 cc of titanium tetraisopropoxide (TTIP) to 100 mL of deionized water. 100 mL of plant extract was added dropwise to the solution with continuous stirring for 4 h at room temperature. Then, it was centrifuged at 4000 rpm for 15 min to remove undissolved biological components. The precipitate was washed repeatedly with water to remove by-products. The nanoparticles were dried at 100 ℃ for 12 h, then calcined in an oven at 500 ℃ for 4 h, and then characterized and evaluated. 2–4. Copper Doping To improve the photocatalytic properties of the nanoparticles, the copper element was doped into titania. In this way, in the nanoparticle synthesis stage, 2.56 g of copper sulfate pentahydrate (preparation of 0.1 M solution of titanium and copper) was added. Doping was done from 1–3% by increasing the copper content and stabilizing the TTIP content. The amount of copper sulfate pentahydrate added increased relative to the mass of TTIP for pure TiO 2 . 2–5. Characterization To determine the phases, crystallite size, and strain in the structure of nanoparticles, X-ray analysis (XRD) was used with a Bruker D8 Advance model with Cu-Kα radiation with λ = 0.1544 nm and 2θ = 10–80 °. The energy bands of the samples were determined using Diffuse reflectance spectroscopy (DRS) analysis performed with a Malvern Nano-ZS90 device. The weight and temperature changes of the samples were examined using thermogravimetric analysis (TGA). The morphology and size of the particles were studied by SEM analysis with a Nova Nano-SEM 450 device and TEM analysis with a Philips EM 208S TEM device. 3. Results and Discussion The XRD pattern of TiO 2 nanoparticles synthesized with Sage plant extract is shown in Fig. 1 . Its diffraction pattern shows no sharp peaks. So, the particles have an amorphous structure. The amorphous phase will not have photocatalytic activity due to the high concentration of structural defects because the defects in the crystal structure can act as recombination centers [ 20 ]. Therefore, using this plant to synthesize titania nanoparticles is not suitable for the conditions of this research. To determine the appropriate calcination temperature in the green synthesis of titania nanoparticles with aloe vera extract, weight changes with temperature were measured using TGA analysis from room temperature to 1000°C. According to the TGA spectrum in Fig. 2 , the weight loss of titania nanoparticles occurred in two stages. The first weight loss stage occurred at room temperature up to 407°C. This weight loss was about 7.3% due to the decomposition of residual organic compounds. The second weight loss occurred at 407°C to 1000°C, which was about 8.5%, and was due to the formation of different TiO 2 phases. Also, the phase transformation of anatase to rutile at temperatures above 450°C is another reason for the weight loss. The insignificant weight change continues from 400°C to 1000°C. Since there is no significant change in weight after 400°C, it is considered the optimal temperature for calcination [ 21 , 22 ]. Therefore, 500, 550, and 600°C calcination temperatures were investigated to synthesize TiO 2 nanoparticles. Figure 3 shows the XRD pattern of 2% Cu-doped titania synthesized with Aloe vera extract and calcined at different temperatures. The peaks observed at 25.34, 37.92, 48.04, and 62.87° correspond to the (101), (004), (200), and (204) planes, respectively, which are in good agreement with the standard data (JCPDS 21-1272) [ 15 , 23 ]. The XRD pattern of TiO 2 nanoparticles calcined at 500°C showed dominant peaks at 25.44° and 54.44°, corresponding to the (101) anatase and (211) rutile phase planes of TiO 2 nanoparticles, respectively. Using Eq. 1, the crystal composition consists of 89% rutile and 11% anatase [ 24 , 25 ]: Where W R is the percentage of the rutile phase, I A is the most intense peak of the anatase phase related to the (101) plane, and I R is the most intense peak of the rutile phase related to the (211) plane. Calcination at 550°C and 650°C has increased the percentage of rutile phase. The crystallite size can be calculated by the Scherrer equation (Eq. 2) and Williamson-Hall equation (Eq. 3) [ 26 ]: where D is the crystallite size, k is a constant equal to 0.94, λ is the wavelength of the radiation (1.5406 Å for CuKα radiation), β is the peak full width at half maximum intensity (FWHM), θ is the diffraction angle, and ε is the strain due to crystal defects and distortion. The crystallite sizes calculated by these methods are presented in Table 1 . According to XRD results, in the structure of TiO 2 nanoparticles, with increasing calcination temperature (500–600°C), the anatase phase gradually decreased, and the rutile phase increased. With increasing calcination temperature, the intensity of the peaks at the corresponding angles increased, and the crystallite size increased from 3.76 nm to 6.62 nm. The reason for this increase is due to the elimination of grain boundaries between the crystals, which leads to the connection of the crystals with each other and, as a result, the formation of crystals with larger sizes [ 27 ]. A study with increasing calcination temperature from 300 to 800°C showed that the percentage of the anatase phase decreases, and the anatase phase completely converts to the rutile phase at 800°C. Also, with increasing temperature, due to aggregation, the crystallite size of the rutile and anatase phases increases [ 28 ]. Table 1 Results were obtained from the XRD pattern using the Scherrer and Williamson-Hall methods. Sample D, nm ε × 10 − 2 Scherrer Williamson-Hall TiO 2 3.59 27.85 0.33 2TC-500 3.76 11.97 0.08 2TC-600 6.62 19.05 0.76 1TC-550 3.59 10.34 0.27 2TC-550 4.03 9.11 0.04 3TC-550 3.43 4.83 1.17 Figure 4 shows the XRD spectra of titania doped with different amounts of copper. All samples show peaks for the formation of the anatase phase. This indicates that the copper doping maintains the anatase structure at about 550°C. In addition, the presence of copper oxide was not observed in the samples. The almost identical ionic radii of copper and titanium (0.72 Å for Cu and 0.68 Å for Ti) allow the dopant to be well intercalated into the titania lattice. Cu can be located in the intercalated sites because r Ti < r Cu causes strain on the titania lattice and therefore causes a small shift of the FWHM in the XRD pattern [ 23 , 29 , 30 ]. A slight shift in the peaks is observed due to the presence of copper. The addition of copper broadens the peaks, indicating smaller crystallite sizes and its effects on the nucleation and growth of crystal nuclei [ 31 ]Table 1 shows the crystallite sizes calculated by these methods. Copper's ionic radius is larger than that of titanium's, so when Cu 2+ ions are placed in the titania lattice, a lattice density is created in copper-doped titanium dioxide. According to the results, the crystallite size calculated by the Scherrer formula was reduced from 3.59 to 3.43 nm by adding impurities and from 27.85 to 4.83 nm by the Williamson-Hall formula. The energy of the photo-generated radicals increases with the decrease in crystallite size due to the quantum confinement effect, which improves the photocatalyst performance. In addition, the decrease in crystallite size leads to a larger surface area, thus enhancing the adsorption of reactants and subsequently increasing the photoreactivity [ 32 ]. FESEM and TEM analyses were performed to investigate the effect of copper doping on the morphology and particle size of TiO 2 nanoparticles. Figure 5 shows the FESEM images and size distribution diagram of TiO 2 nanoparticles synthesized using Aloe vera plant and containing different amounts of copper dopant. FESEM images indicate the formation of spherical particles. Figure 6 shows TEM images and size distribution diagrams of TiO 2 nanoparticles with different percentages of copper. These images also confirm that the biosynthesized nanoparticles have a spherical shape with a smooth surface. The average particle size of TiO 2 nanoparticles with 1, 2, and 3% Cu was obtained as 55, 56, and 71 nm, respectively. As can be seen, a bright halo around the nanoparticles is related to the plant extract because the density of the extract is lower than the density of the nanoparticles in the image compared to the light transmission. Figure 7 shows the UV-Vis DRS absorption spectrum of TiO 2 nanoparticles in the 200–1200 nm range. The absorption edges of the Cu-containing nanoparticles are shifted towards longer wavelengths compared to the pure TiO 2 nanoparticles. This shift of the absorption edges towards longer wavelengths indicates that the doped sample can absorb more visible light [ 5 ]. This is attributed to the transition from the valence band (O 2p) to the conduction band (Ti 3d, Ti 4+ orbitals) of the material and the lattice strain. When Cu 2+ ions are doped into the TiO 2 lattice, the optical absorption edge is shifted from the UV to the visible region [ 10 ]. To find the nanoparticles' energy band gap, we used a Tauc plot. We drew a tangent line to the curve's vertical part and found its intersection with a horizontal reference line. The E g values ​​of the synthesized nanoparticles are summarized in Table 2 . It is observed that copper doping resulted in a decrease in the band gap energy. Such that the band gap energy of pure TiO 2 nanoparticles containing 1, 2, and 3% Cu decreased from 3.10 to 2.96, 2.93, and 2.89 eV, respectively. The photocatalyst levels were significantly improved because the charge separation increased, and they prevented the recombination of electron/hole pairs [ 5 ]. Meanwhile, increasing the calcination temperature to 600℃ increases the band gap energy from 2.88 to 2.97 eV. This result was expressed by Sharma et al. as follows: The band gap energy for the sample increased in the temperature range of 300℃ to 600℃, and when the temperature increased to 700℃ and 800℃, the band gap decreased [ 28 ]. Table 2 Calculated band gap for titania nanoparticles. Sample E g (eV) TiO 2 3.10 2TC-500 2.88 2TC-600 2.97 1TC-550 2.96 2TC-550 2.93 3TC-550 2.89 Table 3 shows the results of the antimicrobial test evaluation on different samples. The removal of microdust increases from 89–94% by increasing the calcination temperature from 500 to 550°C. Also, as the temperature rises, the sample resists Escherichia coli more. But, it is less than the P25 sample. To improve the performance of nanoparticles, the copper element was used as an impurity to improve the visible light absorption property and antimicrobial activity. Biomolecules such as flavonoids, alkaloids, polysaccharides, alcohols, and phenolic compounds present in plant materials can play a role in nanoparticle formation, stabilization, and bio-reduction. Therefore, these biomolecules can coat nanoparticles, resulting in a synergistic effect in biomedical applications [ 20 , 33 ]. Titania nanoparticles can react with OH and O 2 to generate oxygen and hydroxyl free radicals adsorbed on the surface. This nanoscale nature implies a significant increase in surface area to volume ratio, which provides maximum contact with ambient water and oxygen and a minimum size that can easily penetrate the cell wall and cell membrane, causing increased intracellular oxidative damage [ 34 ]. The high antibacterial activity of TiO 2 synthesized by plant extracts may be due to the presence and association of reactive oxygen species (ROS) produced by TiO 2 photocatalytic reactions, which are directly involved in the oxidation process leading to the destruction of microorganisms and improved adsorption and surface hydrophilic properties. In addition, the modification of surface charges due to titanium monoxide (TiO) formation on nanoparticles should also be considered. ROS production causes oxidative damage to the organism, indicating that the cell membrane is the main site of ROS attack. Cell membrane damage directly leads to leakage of minerals, proteins, and genetic material, which is the main cause of cell death [ 35 ]. Matsunaga et al. [ 36 ] found that TiO 2 powder catalysts killed 99% of E. coli bacteria in 0.27 h of UV irradiation (1800 µE.m − 2 s − 1 ). Many studies have been conducted to observe the effect of TiO 2 nanoparticle catalysts on various bacteria. Mannes et al. found that ROS formed on TiO 2 surfaces and caused lipid peroxidation reactions and cell death of K − 12 E. coli [ 5 , 19 , 37 ]. Table 3 Results of antimicrobial tests. Test Sample %Reduction Microparticle Testing P25 94 2TC-500 89 2TC-550 91 Microorganism Testing P25 99 2TC-500 92 2TC-550 94 It was shown that copper doping changes the level of the band gap of TiO 2 . Therefore, the crystallite size is reduced and more pollutants can be adsorbed on the TiO 2 surface [ 10 ]. Anpo et al. [ 38 ] first reported anatase particle size's effect on propyne's photocatalytic hydrogenation. It has been pointed out that the energy of photogenerated radicals increases with the decrease in crystallite size due to the quantum confinement effect, which improves photocatalytic performance. In addition, the decrease in crystallite size leads to the creation of a larger surface area, thus improving the adsorption of reactants and subsequently increasing the photon reactivity [ 39 ]. This study also proved that the crystallite size decreases with added copper dopant. So, the photocatalytic activity increases with the added copper. The results of removing pollutants in the air in Table 4 also prove this. Adding copper dopant increases the photocatalytic activity, and the pollutant removal efficiency also increases. Also, the efficiency of carbon monoxide, sulfur dioxide, nitrogen dioxide, and benzene removal related to titanium dioxide nanoparticles doped with 1, 2, and 3% Cu, and on average, the removal of total suspended particles has increased. Table 4 Results of removal of airborne pollutants. Parameter Removal efficiency (%) P25 1TC-550 2TC-550 3TC-550 Average total particulate matter removal 99 91 92 94 CO 66 62 63 64 SO 2 70 67 68 68 NO 2 65 63 64 66 Benzene 68 69 70 71 Escherichia coli (E. coli) and coronavirus were used to investigate the antimicrobial properties. TiO 2 nanoparticles exhibit environmentally friendly bio-properties attributed to their strong oxidizing potential. These nanoparticles have been used against various infectious microbes, including various strains of bacteria, fungi, algae, protozoa, viruses, and microbial toxins [ 40 ]. The antibacterial activity of TiO 2 is related to the production of reactive oxygen species, especially hydroxyl and peroxide free radicals formed under UV irradiation through oxidative and reductive pathways. In suspension, TiO 2 nanoparticles are trapped on the surface of bacteria, which leads to the adsorption of TiO 2 particles on the bacterial surface and can lead to the inactivation of bacteria along with a photocatalytic oxidation reaction. There are several possible mechanisms to explain the bactericidal effect of TiO 2 nanoparticles. TiO 2 exhibits antimicrobial activity due to its strong oxidizing properties when exposed to sunlight or ultraviolet radiation. The microbial surface was the primary target of the initial oxidative attack when the irradiated TiO 2 particles came into contact with microbes [ 41 ]. According to what was said earlier and the results of Table 5 , increasing the percentage of copper also increased the photocatalytic activity and the removal efficiency of Escherichia coli and coronavirus. Table 5 Results of microorganism removal. Parameter Removal efficiency (%) P25 1TC-550 2TC-550 3TC-550 E. Coli 99 93 94 96 Coronavirus 95 90 91 91 Conclusion In this study, the green synthesis of copper-doped TiO 2 nanoparticles using Aloe vera extract was investigated and represents a serious approach for using nanoparticles for antibacterial and air purification purposes. XRD, DRS, FE-SEM, and TEM techniques determined the crystal size, morphology, and band gap energy. Titania nanoparticles have a spherical crystal structure with a rutile and anatase crystal composition. DRS measurements showed increased adsorption capacity and consequently increased the photocatalytic activity of Cu-doped TiO 2 nanoparticles. The doped nanoparticles were better than the undoped ones. They had superior photocatalytic and antimicrobial activity against bacteria and airborne pollutants. It was observed that, under light, increasing the dopant from 1–3% raised the bacterial removal rate from 93–96% and the particulate matter removal from 91–94%. The results showed that Cu-doped TiO 2 nanoparticles synthesized with Aloe vera could act as a candidate for photocatalytic air purification. Declarations Author Contribution H.Koohestani and H.Gholami designed and performed the experiments. N.Arefipour carried out the experiment. N.Arefipour and H.Koohestani wrote the manuscript. Funding Declaration: The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. References Ambrus, Z., et al., Synthesis, structure and photocatalytic properties of Fe(III)-doped TiO2 prepared from TiCl3. Applied Catalysis B: Environmental, 2008. 81 (1): p. 27-37. Koohestani, H., S.K. Sadrnezhaad, and A. Kheilnejad, Investigation of photocatalytic performance of TiO2 network and fiber geometries. Desalination and Water Treatment, 2016. 57 (50): p. 23644-23650. Subhapriya, S. and P.G.P. Ponnaiah, Green synthesis of titanium dioxide (TiO2) nanoparticles by Trigonella foenum-graecum extract and its antimicrobial properties. Microbial pathogenesis, 2018. 116 . Suh, M., et al., Reactions of Hydroxyl Radicals on Titania, Silica, Alumina, and Gold Surfaces. Journal of Physical Chemistry B - J PHYS CHEM B, 2000. 104 . Ramzan, M., et al., Green synthesis of Cu@TiO2 via cedrus deodara leaf extract: A novel composite with high photocatalytic and antibacterial activity. Current Research in Green and Sustainable Chemistry, 2021. 4 : p. 100137. Koohestani, H., et al., Investigation of photocatalytic performance of natural zeolite/TiO2 composites. Micro & Nano Letters, 2019. 14 (6): p. 669-673. Binas, V., et al., Modified TiO2 based photocatalysts for improved air and health quality. Journal of Materiomics, 2017. 3 (1): p. 3-16. Piątkowska, A., et al., C-,N- and S-Doped TiO2 Photocatalysts: A Review. Catalysts, 2021. 11 (1): p. 144. Zaleska-Medynska, A., Doped-TiO2: a review. Recent Patents on Engineering, 2008. 2 : p. 157-164. Raguram, T. and K.S. Rajni, Synthesis and characterisation of Cu - Doped TiO2 nanoparticles for DSSC and photocatalytic applications. International Journal of Hydrogen Energy, 2022. 47 (7): p. 4674-4689. Lin, J.C.-T., et al., Application of visible light on copper-doped titanium dioxide catalyzing degradation of chlorophenols. Separation and Purification Technology, 2018. 191 : p. 233-243. Dahlan, D., et al., Synthesis of two-dimensional nanowall of Cu-Doped TiO2 and its application as photoanode in DSSCs. Physica E: Low-dimensional Systems and Nanostructures, 2017. 91 : p. 185-189. Pirsaheb, M., et al., Solar degradation of malachite green using nickel-doped TiO2 nanocatalysts. Desalination and Water Treatment, 2016. 57 (21): p. 9881-9888. Koohestani, H., M. Nabilo, and A. Balooch, Biosynthesis and investigation of antibacterial properties of green silver nanoparticles using fruit extracts of Wild barberry, Medlar (Mespilus germanica L.), and Hawthorn. Food Chemistry Advances, 2024: p. 100850. Raorane, D., et al., Green and Rapid Synthesis of Copper-Doped TiO2 Nanoparticles with Increased Photocatalytic Activity. Advances in Chemical Science, 2017. 6 : p. 13. Kumar, P.S.M., Biosynthesized and Chemically Synthesized Titania Nanoparticles: Comparative Analysis of Antibacterial Activity. Journal of Environmental Nanotechnology, 2014. 3 : p. 73-81. Sundrarajan, M. and S. Gowri, Green synthesis of titanium dioxide nanoparticles by nyctanthes arbor-tristis leaves extract. Chalcogenide Letters, 2011. 8 . Villagrán, Z., et al., Plant-Based Extracts as Reducing, Capping, and Stabilizing Agents for the Green Synthesis of Inorganic Nanoparticles. Resources, 2024. 13 (6): p. 70. Rajkumari, J., et al., Synthesis of titanium oxide nanoparticles using Aloe barbadensis mill and evaluation of its antibiofilm potential against Pseudomonas aeruginosa PAO1. Journal of Photochemistry and Photobiology B: Biology, 2019. 201 : p. 111667. Syamsol Bahri, S., et al., Review on recent advance biosynthesis of TiO2 nanoparticles from plant-mediated materials: characterization, mechanism and application. IOP Conference Series: Materials Science and Engineering, 2021. 1142 (1): p. 012005. Saikumari, N., S.M. Dev, and S.A. Dev, Effect of calcination temperature on the properties and applications of bio extract mediated titania nano particles. Scientific Reports, 2021. 11 (1): p. 1734. Kandregula, G.R., Green Synthesis of TiO2 Nanoparticles Using Aloe Vera Extract. International Journal of Advanced Research in Physical Science, 2015. 2 : p. 28-34. López, R., R. Gómez, and M.E. Llanos, Photophysical and photocatalytic properties of nanosized copper-doped titania sol–gel catalysts. Catalysis Today, 2009. 148 (1): p. 103-108. Velardi, L., et al., Effect of temperature on the physical, optical and photocatalytic properties of TiO2 nanoparticles. SN Applied Sciences, 2020. 2 (4): p. 707. Koohestani, H. and S.K. Sadrnezhaad, Improvement in TiO2 photocatalytic performance by ZrO2 nanocompositing and immobilizing. Desalination and Water Treatment, 2016. 57 (58): p. 28450-28459. Khorsand Zak, A., et al., Synthesis, magnetic properties and X-ray analysis of Zn0.97X0.03O nanoparticles (X = Mn, Ni, and Co) using Scherrer and size–strain plot methods. Solid State Sciences, 2012. 14 : p. 488-494. Rezaee, O., H. Chenari, and F. Ghodsi, Synthesis, characterization and photocatalytic activity study of tungsten trioxide nanoparticles calcined at different temperatures. Modern Research Physics, 2018. 2 : p. 45-58. Lal, M., P. Sharma, and C. Ram, Calcination temperature effect on titanium oxide (TiO2) nanoparticles synthesis. Optik, 2021. 241 : p. 166934. Pedroza-Herrera, G., et al., Evaluation of the Photocatalytic Activity of Copper Doped TiO2 nanoparticles for the Purification and/or Disinfection of Industrial Effluents. Catalysis Today, 2020. 341 : p. 37-48. Thakur, B., A. Kumar, and D. Kumar, Green synthesis of titanium dioxide nanoparticles using Azadirachta indica leaf extract and evaluation of their antibacterial activity. South African Journal of Botany, 2019. 124 : p. 223-227. Prathna, T.C., et al., Biomimetic synthesis of silver nanoparticles by Citrus limon (lemon) aqueous extract and theoretical prediction of particle size. Colloids and Surfaces B: Biointerfaces, 2011. 82 (1): p. 152-159. Wang, X., et al., The influence of crystallite size and crystallinity of anatase nanoparticles on the photo-degradation of phenol. Journal of Catalysis, 2014. 310 : p. 100-108. Taleb Safa, M.A. and H. Koohestani, Green synthesis of silver nanoparticles with green tea extract from silver recycling of radiographic films. Results in Engineering, 2024. 21 : p. 101808. Carol López de, D., et al., Antimicrobial Effect of Titanium Dioxide Nanoparticles , in Antimicrobial Resistance , M. Mihai, et al., Editors. 2020, IntechOpen: Rijeka. p. Ch. 5. Maurya, A., et al., Surface Functionalization of TiO 2 with Plant Extracts and their Combined Antimicrobial Activities Against E. faecalis and E. Coli. Journal of Research Updates in Polymer Science, 2012. 1 : p. 43-51. Matsunaga, T. and M. Okochi, TiO2-Mediated Photochemical Disinfection of Escherichia coli Using Optical Fibers. Environ Sci Technol, 1995. 29 (2): p. 501-5. Verma, V., et al., A Review on Green Synthesis of TiO2 NPs: Photocatalysis and Antimicrobial Applications. Polymers, 2022. 14 (7): p. 1444. Anpo, M., et al., Photocatalytic hydrogenation of propyne with water on small-particle titania: size quantization effects and reaction intermediates. The Journal of Physical Chemistry, 1987. 91 (16): p. 4305-4310. Wang, X., et al., The influence of crystallite size and crystallinity of anatase nanoparticles on the photo-degradation of phenol. Journal of Catalysis, 2014. 310 : p. 100–108. Nadeem, M., et al., The current trends in the green syntheses of titanium oxide nanoparticles and their applications. Green Chemistry Letters and Reviews, 2018. 11 (4): p. 492-502. Santhoshkumar, T., et al., Green synthesis of titanium dioxide nanoparticles using Psidium guajava extract and its antibacterial and antioxidant properties. Asian Pacific Journal of Tropical Medicine, 2014. 7 (12): p. 968-976. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted 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. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-5925522","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":409581622,"identity":"19d9b64f-3a41-4f22-877c-c62bfad7956f","order_by":0,"name":"Niloofar Arefipour","email":"","orcid":"","institution":"Semnan University","correspondingAuthor":false,"prefix":"","firstName":"Niloofar","middleName":"","lastName":"Arefipour","suffix":""},{"id":409581623,"identity":"26902ba9-80c2-4e22-8613-d1dcc77cac90","order_by":1,"name":"Hassan Koohestani","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIie2PrW7DMBRGbxTJIa5KIy0P4aggqxTVDzKSKFKR3ScoMDLyNLq+ReDGHFnKyKrRwo4HtKwgVeeqpKDOVjbgw+7P0XcvgMfzDyGAAAJxKfTuaoJ/Vc4bzevdSuhcuyYDVG73bzml0boxeZ8/ZdFaw2EJSSZuK1OBTLr6nJcKLwrD5Zy/q0URqBZwoh2H6Ug+jKQpMDBiuDC81ozASACOXb9clBPF446Yx/7E66+OBMdBBbVW0YGKbQogzesNI+FgikFVupJVqTYdaZ5lZRUbl7SxW/mQ6XYvZzR6YZPdoZ/Zw1j63S1z6lIgvNXUAE7B4/F4PH/gBzzwWOIUS7xKAAAAAElFTkSuQmCC","orcid":"","institution":"Semnan University","correspondingAuthor":true,"prefix":"","firstName":"Hassan","middleName":"","lastName":"Koohestani","suffix":""},{"id":409581624,"identity":"9626ce18-6e1d-4e2f-ac1f-b2ab71732184","order_by":2,"name":"Hedayat Gholami","email":"","orcid":"","institution":"University of Tehran","correspondingAuthor":false,"prefix":"","firstName":"Hedayat","middleName":"","lastName":"Gholami","suffix":""}],"badges":[],"createdAt":"2025-01-29 16:23:08","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5925522/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5925522/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":75447449,"identity":"9ed25b61-2b9a-42b9-8e0a-91ea3122c009","added_by":"auto","created_at":"2025-02-04 16:56:00","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":96982,"visible":true,"origin":"","legend":"\u003cp\u003eXRD pattern of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles synthesized using \u003cem\u003eSage\u003c/em\u003e plant extract.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/cca6b3094668ca4f33b666db.png"},{"id":75447450,"identity":"4894faf0-f0ab-4649-b541-3613aa42ba8d","added_by":"auto","created_at":"2025-02-04 16:56:00","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":15475,"visible":true,"origin":"","legend":"\u003cp\u003eTGA spectrum of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles biosynthesized with \u003cem\u003eAloe vera\u003c/em\u003e plant extract.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/fc50b5ffd5e2c652bd2abf7c.png"},{"id":75447451,"identity":"398bb7ec-c970-4d04-8422-434b59adc05f","added_by":"auto","created_at":"2025-02-04 16:56:00","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":134022,"visible":true,"origin":"","legend":"\u003cp\u003eXRD pattern of samples synthesized with \u003cem\u003eAloe vera\u003c/em\u003e extract and calcined at different temperatures (A: anatase and R: rutile).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/50a6bea64b4ff635df778246.png"},{"id":75447456,"identity":"7ebe99ed-7786-474a-ae98-93db3aba2e4b","added_by":"auto","created_at":"2025-02-04 16:56:00","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":82576,"visible":true,"origin":"","legend":"\u003cp\u003eXRD pattern of nanoparticles synthesized using \u003cem\u003eAloe vera\u003c/em\u003e extract and doped with different amounts of copper (A: anatase and R: rutile).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/af916907840cccb8cf08b654.png"},{"id":75447467,"identity":"131d8bf6-3e5c-4ac2-a7e6-a766f92db3bd","added_by":"auto","created_at":"2025-02-04 16:56:00","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":283597,"visible":true,"origin":"","legend":"\u003cp\u003eFESEM images of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles doped with a) 1, b) 2, and c) 3% Cu.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/757aec51467f426ab088a1ab.png"},{"id":75447461,"identity":"a741bb0c-4064-4b51-8094-cf5bd4d620d9","added_by":"auto","created_at":"2025-02-04 16:56:00","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":216595,"visible":true,"origin":"","legend":"\u003cp\u003eTEM images of biosynthesized Cu-dopped TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles with a) 1% Cu, b) 2% Cu, and c) 3% Cu.\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/db2e8468d341bae7e38c2bc5.png"},{"id":75448239,"identity":"ee02ce2f-6014-464c-93ef-42d6a471c7bb","added_by":"auto","created_at":"2025-02-04 17:12:00","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":55711,"visible":true,"origin":"","legend":"\u003cp\u003eDRS spectra of biosynthesized TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles a) with different percentages of Cu and b) at different calcination temperatures.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/0e3da7fa53a2c853081d5038.png"},{"id":76405823,"identity":"ab4454c3-eced-4efe-a14a-fcf0c2f94799","added_by":"auto","created_at":"2025-02-16 19:46:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1656180,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5925522/v1/c45d5423-c099-4a4d-9cea-fa41ddcca512.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eBiosynthesis of Cu-doped TiO\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e\u003cstrong\u003e nanoparticles with \u003c/strong\u003e\u003cem\u003e\u003cstrong\u003eAloe vera\u003c/strong\u003e\u003c/em\u003e\u003cstrong\u003e extract for air purification and disinfection\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eAs the need for a clean environment grows, so must pollutant removal standards. Thus, new methods for purifying water and air are increasingly important. Titania (TiO\u003csub\u003e2\u003c/sub\u003e) is widely used as a photocatalyst for degrading toxic organic compounds in the aqueous and gas phases [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Titania nanoparticles can react with OH and O\u003csub\u003e2\u003c/sub\u003e, providing oxygen and hydroxyl free radicals for oxidation-reduction reactions. Due to the increased surface area of ​​the nanoparticles, the surface area for interaction with pathogenic bacteria increases, making them suitable as antimicrobial agents. The small size of the particles enables them to easily enter the surface of bacteria and cause damage to them [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTitania has three different phases: anatase, rutile, and brookite. Titania has a wide energy band gap of 3-3.2 eV that is excited only by UV light with wavelengths below 400 nm. In addition, only a small fraction (less than 5%) of the solar spectrum at the Earth\u0026rsquo;s surface is UV light [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Therefore, considerable efforts have been made in recent years to improve the catalytic activity of titania using visible light by modifying its properties, such as specific surface area and energy band gap (E\u003csub\u003eg\u003c/sub\u003e). Doping titania with nonmetallic (C, N, S, I) and metallic (Cr, Mn, Fe, Ni) ions is a practical and attractive way to reduce the band gap and thus extend its photocatalytic response to the visible region of the solar spectrum. Adding a dopant changes the electronic structure of titania, such that by increasing the valence band level and/or decreasing the conduction band energy, its band gap decreases, and its absorption ability shifts to the visible region [\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSeveral methods, such as sol-gel [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], co-precipitation [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], liquid phase precipitation [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], and hydrothermal [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] have been used to synthesize titania nanoparticles. In comparison, biological synthesis is an environmentally friendly protocol that involves the use of various parts and types of biogenic natural sources such as bacteria (intracellular and extracellular), fungi, yeasts, viruses, and various parts of green plants (flowers, stems, roots, leaves, and fruits). Biological sources, both as reducing agents and stabilizing agents, can prevent the overall growth of nanoparticles during the synthesis process. In addition, titania nanoparticles obtained by this method are safe, non-toxic, environmentally friendly, and require minimal energy [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Due to the diversity of plants, the synthesis of nanoparticles from plants is an interesting topic worldwide, as different plant species are rapidly being investigated and used to synthesize nanoparticles. Studies for the biosynthesis of titania nanoparticles using plants such as Azadirachta indica, Nyctanthes tristis-arbor, Hibiscus flower, and Catharanthus roseus with leaves, fruits, bark, flowers, etc., have been reported [\u003cspan additionalcitationids=\"CR16 CR17\" citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003cem\u003eSage\u003c/em\u003e and \u003cem\u003eAloe vera\u003c/em\u003e are among the oldest medicinal plants, with antimicrobial properties and the ability to purify ambient air. Carboxylic acids, terpenoids, flavonoids, and proteins present in Aloe vera leaf extract help form titania nanoparticles and act as a capping agent and reducing agent in the biosynthesis process [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. For this reason, Sage and Aloe vera were used in this study to synthesize titania and copper-doped titania. Various analyses then characterized the nanoparticles and evaluated their performance in air purification.\u003c/p\u003e"},{"header":"2. Materials and Methods","content":"\n\u003ch3\u003e2 − 1. Materials\u003c/h3\u003e\n\u003cp\u003eFor this work, titanium tetraisopropoxide (99.9%) (C\u003csub\u003e12\u003c/sub\u003eH\u003csub\u003e28\u003c/sub\u003eO\u003csub\u003e4\u003c/sub\u003eTi) was purchased from Dae Jung, and copper sulfate pentahydrate (99.9%) was purchased from Sigma Aldrich. \u003cem\u003eAloe vera\u003c/em\u003e and \u003cem\u003eSage\u003c/em\u003e were obtained from different regions of Iran.\u003c/p\u003e\n\u003ch3\u003e2–2. Extract preparation\u003c/h3\u003e\n\u003cp\u003eTo prepare the extract, a certain amount of plant (50 g fresh \u003cem\u003eAloe vera\u003c/em\u003e leaves, 25 g dried \u003cem\u003eSage\u003c/em\u003e plant) was added to 250 ml deionized water and stirred at 90\u0026deg;C for 2 h. Finally, the resulting mixture was filtered using filter paper to remove the plant residue.\u003c/p\u003e\n\u003ch3\u003e2–3. Green Synthesis of Titania Nanoparticles\u003c/h3\u003e\n\u003cp\u003eA 0.1 M titanium solution was prepared by adding 2.96 cc of titanium tetraisopropoxide (TTIP) to 100 mL of deionized water. 100 mL of plant extract was added dropwise to the solution with continuous stirring for 4 h at room temperature. Then, it was centrifuged at 4000 rpm for 15 min to remove undissolved biological components. The precipitate was washed repeatedly with water to remove by-products. The nanoparticles were dried at 100 ℃ for 12 h, then calcined in an oven at 500 ℃ for 4 h, and then characterized and evaluated.\u003c/p\u003e\n\u003ch3\u003e2–4. Copper Doping\u003c/h3\u003e\n\u003cp\u003eTo improve the photocatalytic properties of the nanoparticles, the copper element was doped into titania. In this way, in the nanoparticle synthesis stage, 2.56 g of copper sulfate pentahydrate (preparation of 0.1 M solution of titanium and copper) was added. Doping was done from 1\u0026ndash;3% by increasing the copper content and stabilizing the TTIP content. The amount of copper sulfate pentahydrate added increased relative to the mass of TTIP for pure TiO\u003csub\u003e2\u003c/sub\u003e.\u003c/p\u003e\n\u003ch3\u003e2–5. Characterization\u003c/h3\u003e\n\u003cp\u003eTo determine the phases, crystallite size, and strain in the structure of nanoparticles, X-ray analysis (XRD) was used with a Bruker D8 Advance model with Cu-Kα radiation with λ\u0026thinsp;=\u0026thinsp;0.1544 nm and 2θ\u0026thinsp;=\u0026thinsp;10\u0026ndash;80 \u0026deg;. The energy bands of the samples were determined using Diffuse reflectance spectroscopy (DRS) analysis performed with a Malvern Nano-ZS90 device. The weight and temperature changes of the samples were examined using thermogravimetric analysis (TGA). The morphology and size of the particles were studied by SEM analysis with a Nova Nano-SEM 450 device and TEM analysis with a Philips EM 208S TEM device.\u003c/p\u003e"},{"header":"3. Results and Discussion","content":"\u003cp\u003eThe XRD pattern of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles synthesized with \u003cem\u003eSage\u003c/em\u003e plant extract is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Its diffraction pattern shows no sharp peaks. So, the particles have an amorphous structure. The amorphous phase will not have photocatalytic activity due to the high concentration of structural defects because the defects in the crystal structure can act as recombination centers [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Therefore, using this plant to synthesize titania nanoparticles is not suitable for the conditions of this research.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo determine the appropriate calcination temperature in the green synthesis of titania nanoparticles with aloe vera extract, weight changes with temperature were measured using TGA analysis from room temperature to 1000°C. According to the TGA spectrum in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, the weight loss of titania nanoparticles occurred in two stages. The first weight loss stage occurred at room temperature up to 407°C. This weight loss was about 7.3% due to the decomposition of residual organic compounds. The second weight loss occurred at 407°C to 1000°C, which was about 8.5%, and was due to the formation of different TiO\u003csub\u003e2\u003c/sub\u003e phases. Also, the phase transformation of anatase to rutile at temperatures above 450°C is another reason for the weight loss. The insignificant weight change continues from 400°C to 1000°C. Since there is no significant change in weight after 400°C, it is considered the optimal temperature for calcination [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Therefore, 500, 550, and 600°C calcination temperatures were investigated to synthesize TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the XRD pattern of 2% Cu-doped titania synthesized with \u003cem\u003eAloe vera\u003c/em\u003e extract and calcined at different temperatures. The peaks observed at 25.34, 37.92, 48.04, and 62.87° correspond to the (101), (004), (200), and (204) planes, respectively, which are in good agreement with the standard data (JCPDS 21-1272) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. The XRD pattern of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles calcined at 500°C showed dominant peaks at 25.44° and 54.44°, corresponding to the (101) anatase and (211) rutile phase planes of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles, respectively. Using Eq.\u0026nbsp;1, the crystal composition consists of 89% rutile and 11% anatase [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]:\u003c/p\u003e\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"194\" height=\"59\"\u003e\u003c/p\u003e\u003cp\u003eWhere W\u003csub\u003eR\u003c/sub\u003e is the percentage of the rutile phase, I\u003csub\u003eA\u003c/sub\u003e is the most intense peak of the anatase phase related to the (101) plane, and I\u003csub\u003eR\u003c/sub\u003e is the most intense peak of the rutile phase related to the (211) plane. Calcination at 550°C and 650°C has increased the percentage of rutile phase. The crystallite size can be calculated by the Scherrer equation (Eq.\u0026nbsp;2) and Williamson-Hall equation (Eq.\u0026nbsp;3) [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]:\u003c/p\u003e\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"222\" height=\"85\"\u003e\u003c/p\u003e\u003cp\u003ewhere D is the crystallite size, k is a constant equal to 0.94, λ is the wavelength of the radiation (1.5406 Å for CuKα radiation), β is the peak full width at half maximum intensity (FWHM), θ is the diffraction angle, and ε is the strain due to crystal defects and distortion. The crystallite sizes calculated by these methods are presented in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAccording to XRD results, in the structure of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles, with increasing calcination temperature (500–600°C), the anatase phase gradually decreased, and the rutile phase increased. With increasing calcination temperature, the intensity of the peaks at the corresponding angles increased, and the crystallite size increased from 3.76 nm to 6.62 nm. The reason for this increase is due to the elimination of grain boundaries between the crystals, which leads to the connection of the crystals with each other and, as a result, the formation of crystals with larger sizes [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. A study with increasing calcination temperature from 300 to 800°C showed that the percentage of the anatase phase decreases, and the anatase phase completely converts to the rutile phase at 800°C. Also, with increasing temperature, due to aggregation, the crystallite size of the rutile and anatase phases increases [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\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\u003eResults were obtained from the XRD pattern using the Scherrer and Williamson-Hall methods.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e \u003cp\u003eD, nm\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eε × 10\u003csup\u003e− 2\u003c/sup\u003e\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eScherrer\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eWilliamson-Hall\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.59\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e27.85\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2TC-500\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.76\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e11.97\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.08\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2TC-600\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.62\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e19.05\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.76\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.59\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.34\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.27\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4.03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e9.11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.43\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e4.83\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.17\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows the XRD spectra of titania doped with different amounts of copper. All samples show peaks for the formation of the anatase phase. This indicates that the copper doping maintains the anatase structure at about 550°C. In addition, the presence of copper oxide was not observed in the samples. The almost identical ionic radii of copper and titanium (0.72 Å for Cu and 0.68 Å for Ti) allow the dopant to be well intercalated into the titania lattice. Cu can be located in the intercalated sites because r\u003csub\u003eTi\u003c/sub\u003e \u0026lt; r\u003csub\u003eCu\u003c/sub\u003e causes strain on the titania lattice and therefore causes a small shift of the FWHM in the XRD pattern [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA slight shift in the peaks is observed due to the presence of copper. The addition of copper broadens the peaks, indicating smaller crystallite sizes and its effects on the nucleation and growth of crystal nuclei [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e shows the crystallite sizes calculated by these methods. Copper's ionic radius is larger than that of titanium's, so when Cu\u003csup\u003e2+\u003c/sup\u003e ions are placed in the titania lattice, a lattice density is created in copper-doped titanium dioxide.\u003c/p\u003e \u003cp\u003eAccording to the results, the crystallite size calculated by the Scherrer formula was reduced from 3.59 to 3.43 nm by adding impurities and from 27.85 to 4.83 nm by the Williamson-Hall formula. The energy of the photo-generated radicals increases with the decrease in crystallite size due to the quantum confinement effect, which improves the photocatalyst performance. In addition, the decrease in crystallite size leads to a larger surface area, thus enhancing the adsorption of reactants and subsequently increasing the photoreactivity [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFESEM and TEM analyses were performed to investigate the effect of copper doping on the morphology and particle size of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the FESEM images and size distribution diagram of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles synthesized using \u003cem\u003eAloe vera\u003c/em\u003e plant and containing different amounts of copper dopant. FESEM images indicate the formation of spherical particles.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e shows TEM images and size distribution diagrams of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles with different percentages of copper. These images also confirm that the biosynthesized nanoparticles have a spherical shape with a smooth surface. The average particle size of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles with 1, 2, and 3% Cu was obtained as 55, 56, and 71 nm, respectively. As can be seen, a bright halo around the nanoparticles is related to the plant extract because the density of the extract is lower than the density of the nanoparticles in the image compared to the light transmission.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e shows the UV-Vis DRS absorption spectrum of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles in the 200–1200 nm range. The absorption edges of the Cu-containing nanoparticles are shifted towards longer wavelengths compared to the pure TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles. This shift of the absorption edges towards longer wavelengths indicates that the doped sample can absorb more visible light [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. This is attributed to the transition from the valence band (O 2p) to the conduction band (Ti 3d, Ti\u003csup\u003e4+\u003c/sup\u003e orbitals) of the material and the lattice strain. When Cu\u003csup\u003e2+\u003c/sup\u003e ions are doped into the TiO\u003csub\u003e2\u003c/sub\u003e lattice, the optical absorption edge is shifted from the UV to the visible region [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo find the nanoparticles' energy band gap, we used a Tauc plot. We drew a tangent line to the curve's vertical part and found its intersection with a horizontal reference line. The E\u003csub\u003eg\u003c/sub\u003e values ​​of the synthesized nanoparticles are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. It is observed that copper doping resulted in a decrease in the band gap energy. Such that the band gap energy of pure TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles containing 1, 2, and 3% Cu decreased from 3.10 to 2.96, 2.93, and 2.89 eV, respectively. The photocatalyst levels were significantly improved because the charge separation increased, and they prevented the recombination of electron/hole pairs [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMeanwhile, increasing the calcination temperature to 600℃ increases the band gap energy from 2.88 to 2.97 eV. This result was expressed by Sharma et al. as follows: The band gap energy for the sample increased in the temperature range of 300℃ to 600℃, and when the temperature increased to 700℃ and 800℃, the band gap decreased [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\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\u003eCalculated band gap for titania nanoparticles.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eE\u003csub\u003eg\u003c/sub\u003e (eV)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.10\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2TC-500\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.88\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2TC-600\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.97\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.96\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.93\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.89\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the results of the antimicrobial test evaluation on different samples. The removal of microdust increases from 89–94% by increasing the calcination temperature from 500 to 550°C. Also, as the temperature rises, the sample resists Escherichia coli more. But, it is less than the P25 sample. To improve the performance of nanoparticles, the copper element was used as an impurity to improve the visible light absorption property and antimicrobial activity. Biomolecules such as flavonoids, alkaloids, polysaccharides, alcohols, and phenolic compounds present in plant materials can play a role in nanoparticle formation, stabilization, and bio-reduction. Therefore, these biomolecules can coat nanoparticles, resulting in a synergistic effect in biomedical applications [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTitania nanoparticles can react with OH and O\u003csub\u003e2\u003c/sub\u003e to generate oxygen and hydroxyl free radicals adsorbed on the surface. This nanoscale nature implies a significant increase in surface area to volume ratio, which provides maximum contact with ambient water and oxygen and a minimum size that can easily penetrate the cell wall and cell membrane, causing increased intracellular oxidative damage [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The high antibacterial activity of TiO\u003csub\u003e2\u003c/sub\u003e synthesized by plant extracts may be due to the presence and association of reactive oxygen species (ROS) produced by TiO\u003csub\u003e2\u003c/sub\u003e photocatalytic reactions, which are directly involved in the oxidation process leading to the destruction of microorganisms and improved adsorption and surface hydrophilic properties. In addition, the modification of surface charges due to titanium monoxide (TiO) formation on nanoparticles should also be considered. ROS production causes oxidative damage to the organism, indicating that the cell membrane is the main site of ROS attack. Cell membrane damage directly leads to leakage of minerals, proteins, and genetic material, which is the main cause of cell death [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMatsunaga et al. [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e] found that TiO\u003csub\u003e2\u003c/sub\u003e powder catalysts killed 99% of E. coli bacteria in 0.27 h of UV irradiation (1800 µE.m\u003csup\u003e− 2\u003c/sup\u003es\u003csup\u003e− 1\u003c/sup\u003e). Many studies have been conducted to observe the effect of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticle catalysts on various bacteria. Mannes et al. found that ROS formed on TiO\u003csub\u003e2\u003c/sub\u003e surfaces and caused lipid peroxidation reactions and cell death of K\u003csup\u003e− 12\u003c/sup\u003e E. coli [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of antimicrobial tests.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTest\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e%Reduction\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eMicroparticle Testing\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP25\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e94\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2TC-500\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e89\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eMicroorganism Testing\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP25\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2TC-500\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e92\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2TC-550\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e94\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eIt was shown that copper doping changes the level of the band gap of TiO\u003csub\u003e2\u003c/sub\u003e. Therefore, the crystallite size is reduced and more pollutants can be adsorbed on the TiO\u003csub\u003e2\u003c/sub\u003e surface [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Anpo et al. [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e] first reported anatase particle size's effect on propyne's photocatalytic hydrogenation. It has been pointed out that the energy of photogenerated radicals increases with the decrease in crystallite size due to the quantum confinement effect, which improves photocatalytic performance. In addition, the decrease in crystallite size leads to the creation of a larger surface area, thus improving the adsorption of reactants and subsequently increasing the photon reactivity [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]. This study also proved that the crystallite size decreases with added copper dopant. So, the photocatalytic activity increases with the added copper. The results of removing pollutants in the air in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e also prove this. Adding copper dopant increases the photocatalytic activity, and the pollutant removal efficiency also increases. Also, the efficiency of carbon monoxide, sulfur dioxide, nitrogen dioxide, and benzene removal related to titanium dioxide nanoparticles doped with 1, 2, and 3% Cu, and on average, the removal of total suspended particles has increased.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of removal of airborne pollutants.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eRemoval efficiency (%)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP25\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1TC-550\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2TC-550\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3TC-550\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAverage total particulate matter removal\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e92\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e94\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCO\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e62\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e65\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e63\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBenzene\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e68\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e69\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e71\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eEscherichia coli (E. coli) and coronavirus were used to investigate the antimicrobial properties. TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles exhibit environmentally friendly bio-properties attributed to their strong oxidizing potential. These nanoparticles have been used against various infectious microbes, including various strains of bacteria, fungi, algae, protozoa, viruses, and microbial toxins [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. The antibacterial activity of TiO\u003csub\u003e2\u003c/sub\u003e is related to the production of reactive oxygen species, especially hydroxyl and peroxide free radicals formed under UV irradiation through oxidative and reductive pathways. In suspension, TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles are trapped on the surface of bacteria, which leads to the adsorption of TiO\u003csub\u003e2\u003c/sub\u003e particles on the bacterial surface and can lead to the inactivation of bacteria along with a photocatalytic oxidation reaction. There are several possible mechanisms to explain the bactericidal effect of TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles. TiO\u003csub\u003e2\u003c/sub\u003e exhibits antimicrobial activity due to its strong oxidizing properties when exposed to sunlight or ultraviolet radiation. The microbial surface was the primary target of the initial oxidative attack when the irradiated TiO\u003csub\u003e2\u003c/sub\u003e particles came into contact with microbes [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. According to what was said earlier and the results of Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, increasing the percentage of copper also increased the photocatalytic activity and the removal efficiency of Escherichia coli and coronavirus.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\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\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of microorganism removal.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eParameter\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eRemoval efficiency (%)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eP25\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1TC-550\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e2TC-550\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3TC-550\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE. Coli\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e93\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e96\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCoronavirus\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e91\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e "},{"header":"Conclusion","content":"\u003cp\u003eIn this study, the green synthesis of copper-doped TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles using \u003cem\u003eAloe vera\u003c/em\u003e extract was investigated and represents a serious approach for using nanoparticles for antibacterial and air purification purposes. XRD, DRS, FE-SEM, and TEM techniques determined the crystal size, morphology, and band gap energy. Titania nanoparticles have a spherical crystal structure with a rutile and anatase crystal composition. DRS measurements showed increased adsorption capacity and consequently increased the photocatalytic activity of Cu-doped TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles. The doped nanoparticles were better than the undoped ones. They had superior photocatalytic and antimicrobial activity against bacteria and airborne pollutants. It was observed that, under light, increasing the dopant from 1–3% raised the bacterial removal rate from 93–96% and the particulate matter removal from 91–94%. The results showed that Cu-doped TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles synthesized with Aloe vera could act as a candidate for photocatalytic air purification.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eH.Koohestani and H.Gholami designed and performed the experiments. N.Arefipour carried out the experiment. N.Arefipour and H.Koohestani wrote the manuscript.\u003c/p\u003e\n\u003ch3\u003eFunding Declaration:\u003c/h3\u003e\n\u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAmbrus, Z., et al., \u003cem\u003eSynthesis, structure and photocatalytic properties of Fe(III)-doped TiO2 prepared from TiCl3.\u003c/em\u003e Applied Catalysis B: Environmental, 2008. \u003cstrong\u003e81\u003c/strong\u003e(1): p. 27-37.\u003c/li\u003e\n\u003cli\u003eKoohestani, H., S.K. Sadrnezhaad, and A. Kheilnejad, \u003cem\u003eInvestigation of photocatalytic performance of TiO2 network and fiber geometries.\u003c/em\u003e Desalination and Water Treatment, 2016. \u003cstrong\u003e57\u003c/strong\u003e(50): p. 23644-23650.\u003c/li\u003e\n\u003cli\u003eSubhapriya, S. and P.G.P. Ponnaiah, \u003cem\u003eGreen synthesis of titanium dioxide (TiO2) nanoparticles by Trigonella foenum-graecum extract and its antimicrobial properties.\u003c/em\u003e Microbial pathogenesis, 2018. \u003cstrong\u003e116\u003c/strong\u003e.\u003c/li\u003e\n\u003cli\u003eSuh, M., et al., \u003cem\u003eReactions of Hydroxyl Radicals on Titania, Silica, Alumina, and Gold Surfaces.\u003c/em\u003e Journal of Physical Chemistry B - J PHYS CHEM B, 2000. \u003cstrong\u003e104\u003c/strong\u003e.\u003c/li\u003e\n\u003cli\u003eRamzan, M., et al., \u003cem\u003eGreen synthesis of Cu@TiO2 via cedrus deodara leaf extract: A novel composite with high photocatalytic and antibacterial activity.\u003c/em\u003e Current Research in Green and Sustainable Chemistry, 2021. \u003cstrong\u003e4\u003c/strong\u003e: p. 100137.\u003c/li\u003e\n\u003cli\u003eKoohestani, H., et al., \u003cem\u003eInvestigation of photocatalytic performance of natural zeolite/TiO2 composites.\u003c/em\u003e Micro \u0026amp; Nano Letters, 2019. \u003cstrong\u003e14\u003c/strong\u003e(6): p. 669-673.\u003c/li\u003e\n\u003cli\u003eBinas, V., et al., \u003cem\u003eModified TiO2 based photocatalysts for improved air and health quality.\u003c/em\u003e Journal of Materiomics, 2017. \u003cstrong\u003e3\u003c/strong\u003e(1): p. 3-16.\u003c/li\u003e\n\u003cli\u003ePiątkowska, A., et al., \u003cem\u003eC-,N- and S-Doped TiO2 Photocatalysts: A Review.\u003c/em\u003e Catalysts, 2021. \u003cstrong\u003e11\u003c/strong\u003e(1): p. 144.\u003c/li\u003e\n\u003cli\u003eZaleska-Medynska, A., \u003cem\u003eDoped-TiO2: a review.\u003c/em\u003e Recent Patents on Engineering, 2008. \u003cstrong\u003e2\u003c/strong\u003e: p. 157-164.\u003c/li\u003e\n\u003cli\u003eRaguram, T. and K.S. Rajni, \u003cem\u003eSynthesis and characterisation of Cu - Doped TiO2 nanoparticles for DSSC and photocatalytic applications.\u003c/em\u003e International Journal of Hydrogen Energy, 2022. \u003cstrong\u003e47\u003c/strong\u003e(7): p. 4674-4689.\u003c/li\u003e\n\u003cli\u003eLin, J.C.-T., et al., \u003cem\u003eApplication of visible light on copper-doped titanium dioxide catalyzing degradation of chlorophenols.\u003c/em\u003e Separation and Purification Technology, 2018. \u003cstrong\u003e191\u003c/strong\u003e: p. 233-243.\u003c/li\u003e\n\u003cli\u003eDahlan, D., et al., \u003cem\u003eSynthesis of two-dimensional nanowall of Cu-Doped TiO2 and its application as photoanode in DSSCs.\u003c/em\u003e Physica E: Low-dimensional Systems and Nanostructures, 2017. \u003cstrong\u003e91\u003c/strong\u003e: p. 185-189.\u003c/li\u003e\n\u003cli\u003ePirsaheb, M., et al., \u003cem\u003eSolar degradation of malachite green using nickel-doped TiO2 nanocatalysts.\u003c/em\u003e Desalination and Water Treatment, 2016. \u003cstrong\u003e57\u003c/strong\u003e(21): p. 9881-9888.\u003c/li\u003e\n\u003cli\u003eKoohestani, H., M. Nabilo, and A. Balooch, \u003cem\u003eBiosynthesis and investigation of antibacterial properties of green silver nanoparticles using fruit extracts of Wild barberry, Medlar (Mespilus germanica L.), and Hawthorn.\u003c/em\u003e Food Chemistry Advances, 2024: p. 100850.\u003c/li\u003e\n\u003cli\u003eRaorane, D., et al., \u003cem\u003eGreen and Rapid Synthesis of Copper-Doped TiO2 Nanoparticles with Increased Photocatalytic Activity.\u003c/em\u003e Advances in Chemical Science, 2017. \u003cstrong\u003e6\u003c/strong\u003e: p. 13.\u003c/li\u003e\n\u003cli\u003eKumar, P.S.M., \u003cem\u003eBiosynthesized and Chemically Synthesized Titania Nanoparticles: Comparative Analysis of Antibacterial Activity.\u003c/em\u003e Journal of Environmental Nanotechnology, 2014. \u003cstrong\u003e3\u003c/strong\u003e: p. 73-81.\u003c/li\u003e\n\u003cli\u003eSundrarajan, M. and S. Gowri, \u003cem\u003eGreen synthesis of titanium dioxide nanoparticles by nyctanthes arbor-tristis leaves extract.\u003c/em\u003e Chalcogenide Letters, 2011. \u003cstrong\u003e8\u003c/strong\u003e.\u003c/li\u003e\n\u003cli\u003eVillagr\u0026aacute;n, Z., et al., \u003cem\u003ePlant-Based Extracts as Reducing, Capping, and Stabilizing Agents for the Green Synthesis of Inorganic Nanoparticles.\u003c/em\u003e Resources, 2024. \u003cstrong\u003e13\u003c/strong\u003e(6): p. 70.\u003c/li\u003e\n\u003cli\u003eRajkumari, J., et al., \u003cem\u003eSynthesis of titanium oxide nanoparticles using Aloe barbadensis mill and evaluation of its antibiofilm potential against Pseudomonas aeruginosa PAO1.\u003c/em\u003e Journal of Photochemistry and Photobiology B: Biology, 2019. \u003cstrong\u003e201\u003c/strong\u003e: p. 111667.\u003c/li\u003e\n\u003cli\u003eSyamsol Bahri, S., et al., \u003cem\u003eReview on recent advance biosynthesis of TiO2 nanoparticles from plant-mediated materials: characterization, mechanism and application.\u003c/em\u003e IOP Conference Series: Materials Science and Engineering, 2021. \u003cstrong\u003e1142\u003c/strong\u003e(1): p. 012005.\u003c/li\u003e\n\u003cli\u003eSaikumari, N., S.M. Dev, and S.A. Dev, \u003cem\u003eEffect of calcination temperature on the properties and applications of bio extract mediated titania nano particles.\u003c/em\u003e Scientific Reports, 2021. \u003cstrong\u003e11\u003c/strong\u003e(1): p. 1734.\u003c/li\u003e\n\u003cli\u003eKandregula, G.R., \u003cem\u003eGreen Synthesis of TiO2 Nanoparticles Using Aloe Vera Extract.\u003c/em\u003e International Journal of Advanced Research in Physical Science, 2015. \u003cstrong\u003e2\u003c/strong\u003e: p. 28-34.\u003c/li\u003e\n\u003cli\u003eL\u0026oacute;pez, R., R. G\u0026oacute;mez, and M.E. Llanos, \u003cem\u003ePhotophysical and photocatalytic properties of nanosized copper-doped titania sol\u0026ndash;gel catalysts.\u003c/em\u003e Catalysis Today, 2009. \u003cstrong\u003e148\u003c/strong\u003e(1): p. 103-108.\u003c/li\u003e\n\u003cli\u003eVelardi, L., et al., \u003cem\u003eEffect of temperature on the physical, optical and photocatalytic properties of TiO2 nanoparticles.\u003c/em\u003e SN Applied Sciences, 2020. \u003cstrong\u003e2\u003c/strong\u003e(4): p. 707.\u003c/li\u003e\n\u003cli\u003eKoohestani, H. and S.K. Sadrnezhaad, \u003cem\u003eImprovement in TiO2 photocatalytic performance by ZrO2 nanocompositing and immobilizing.\u003c/em\u003e Desalination and Water Treatment, 2016. \u003cstrong\u003e57\u003c/strong\u003e(58): p. 28450-28459.\u003c/li\u003e\n\u003cli\u003eKhorsand Zak, A., et al., \u003cem\u003eSynthesis, magnetic properties and X-ray analysis of Zn0.97X0.03O nanoparticles (X = Mn, Ni, and Co) using Scherrer and size\u0026ndash;strain plot methods.\u003c/em\u003e Solid State Sciences, 2012. \u003cstrong\u003e14\u003c/strong\u003e: p. 488-494.\u003c/li\u003e\n\u003cli\u003eRezaee, O., H. Chenari, and F. Ghodsi, \u003cem\u003eSynthesis, characterization and photocatalytic activity study of tungsten trioxide nanoparticles calcined at different temperatures.\u003c/em\u003e Modern Research Physics, 2018. \u003cstrong\u003e2\u003c/strong\u003e: p. 45-58.\u003c/li\u003e\n\u003cli\u003eLal, M., P. Sharma, and C. Ram, \u003cem\u003eCalcination temperature effect on titanium oxide (TiO2) nanoparticles synthesis.\u003c/em\u003e Optik, 2021. \u003cstrong\u003e241\u003c/strong\u003e: p. 166934.\u003c/li\u003e\n\u003cli\u003ePedroza-Herrera, G., et al., \u003cem\u003eEvaluation of the Photocatalytic Activity of Copper Doped TiO2 nanoparticles for the Purification and/or Disinfection of Industrial Effluents.\u003c/em\u003e Catalysis Today, 2020. \u003cstrong\u003e341\u003c/strong\u003e: p. 37-48.\u003c/li\u003e\n\u003cli\u003eThakur, B., A. Kumar, and D. Kumar, \u003cem\u003eGreen synthesis of titanium dioxide nanoparticles using Azadirachta indica leaf extract and evaluation of their antibacterial activity.\u003c/em\u003e South African Journal of Botany, 2019. \u003cstrong\u003e124\u003c/strong\u003e: p. 223-227.\u003c/li\u003e\n\u003cli\u003ePrathna, T.C., et al., \u003cem\u003eBiomimetic synthesis of silver nanoparticles by Citrus limon (lemon) aqueous extract and theoretical prediction of particle size.\u003c/em\u003e Colloids and Surfaces B: Biointerfaces, 2011. \u003cstrong\u003e82\u003c/strong\u003e(1): p. 152-159.\u003c/li\u003e\n\u003cli\u003eWang, X., et al., \u003cem\u003eThe influence of crystallite size and crystallinity of anatase nanoparticles on the photo-degradation of phenol.\u003c/em\u003e Journal of Catalysis, 2014. \u003cstrong\u003e310\u003c/strong\u003e: p. 100-108.\u003c/li\u003e\n\u003cli\u003eTaleb Safa, M.A. and H. Koohestani, \u003cem\u003eGreen synthesis of silver nanoparticles with green tea extract from silver recycling of radiographic films.\u003c/em\u003e Results in Engineering, 2024. \u003cstrong\u003e21\u003c/strong\u003e: p. 101808.\u003c/li\u003e\n\u003cli\u003eCarol L\u0026oacute;pez de, D., et al., \u003cem\u003eAntimicrobial Effect of Titanium Dioxide Nanoparticles\u003c/em\u003e, in \u003cem\u003eAntimicrobial Resistance\u003c/em\u003e, M. Mihai, et al., Editors. 2020, IntechOpen: Rijeka. p. Ch. 5.\u003c/li\u003e\n\u003cli\u003eMaurya, A., et al., \u003cem\u003eSurface Functionalization of TiO 2 with Plant Extracts and their Combined Antimicrobial Activities Against E. faecalis and E. Coli.\u003c/em\u003e Journal of Research Updates in Polymer Science, 2012. \u003cstrong\u003e1\u003c/strong\u003e: p. 43-51.\u003c/li\u003e\n\u003cli\u003eMatsunaga, T. and M. Okochi, \u003cem\u003eTiO2-Mediated Photochemical Disinfection of Escherichia coli Using Optical Fibers.\u003c/em\u003e Environ Sci Technol, 1995. \u003cstrong\u003e29\u003c/strong\u003e(2): p. 501-5.\u003c/li\u003e\n\u003cli\u003eVerma, V., et al., \u003cem\u003eA Review on Green Synthesis of TiO2 NPs: Photocatalysis and Antimicrobial Applications.\u003c/em\u003e Polymers, 2022. \u003cstrong\u003e14\u003c/strong\u003e(7): p. 1444.\u003c/li\u003e\n\u003cli\u003eAnpo, M., et al., \u003cem\u003ePhotocatalytic hydrogenation of propyne with water on small-particle titania: size quantization effects and reaction intermediates.\u003c/em\u003e The Journal of Physical Chemistry, 1987. \u003cstrong\u003e91\u003c/strong\u003e(16): p. 4305-4310.\u003c/li\u003e\n\u003cli\u003eWang, X., et al., \u003cem\u003eThe influence of crystallite size and crystallinity of anatase nanoparticles on the photo-degradation of phenol.\u003c/em\u003e Journal of Catalysis, 2014. \u003cstrong\u003e310\u003c/strong\u003e: p. 100\u0026ndash;108.\u003c/li\u003e\n\u003cli\u003eNadeem, M., et al., \u003cem\u003eThe current trends in the green syntheses of titanium oxide nanoparticles and their applications.\u003c/em\u003e Green Chemistry Letters and Reviews, 2018. \u003cstrong\u003e11\u003c/strong\u003e(4): p. 492-502.\u003c/li\u003e\n\u003cli\u003eSanthoshkumar, T., et al., \u003cem\u003eGreen synthesis of titanium dioxide nanoparticles using Psidium guajava extract and its antibacterial and antioxidant properties.\u003c/em\u003e Asian Pacific Journal of Tropical Medicine, 2014. \u003cstrong\u003e7\u003c/strong\u003e(12): p. 968-976.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"TiO2, Biosynthesis, Copper Doping, Air Purification, Aloe Vera Extract, Sage Extract","lastPublishedDoi":"10.21203/rs.3.rs-5925522/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5925522/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe use of plant extracts for the synthesis of nanoparticles has attracted much attention due to its simplicity, environmental friendliness, and cost-effectiveness. This study synthesized titanium dioxide (TiO2) nanoparticles using Aloe vera and Salvia extracts. Its doping with copper was also investigated to reduce the electron/hole pair recombination rate and improve the photocatalytic activity of titania. Biosynthesized titania (TiO\u003csub\u003e2\u003c/sub\u003e) nanoparticles were characterized by X-ray diffraction (XRD), Diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM). XRD reported the formation of crystals with sizes of 4\u0026ndash;7 nm by the Scherrer method and 5\u0026ndash;27 nm by the Williamson-Hall method. FE-SEM and TEM analysis showed the formation of spherical particles. Spectroscopic results showed that adding copper element reduced the band gap energy from 3.10 eV to 2.89 eV. These results increased the removal efficiency of suspended particles, Escherichia coli bacteria, and coronavirus by titania nanoparticles. Therefore, Cu-TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles biosynthesized with \u003cem\u003eAloe vera\u003c/em\u003e extract showed increased photocatalytic and antibacterial activity that can be used for air purification.\u003c/p\u003e","manuscriptTitle":"Biosynthesis of Cu-doped TiO2 nanoparticles with Aloe vera extract for air purification and disinfection","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-04 16:55:55","doi":"10.21203/rs.3.rs-5925522/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"be491e8e-3e4a-4be1-a7cd-9ca36cd2917e","owner":[],"postedDate":"February 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-02-16T19:38:22+00:00","versionOfRecord":[],"versionCreatedAt":"2025-02-04 16:55:55","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5925522","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5925522","identity":"rs-5925522","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}