Microwave-Assisted Synthesis and Evaluation of SnO 2 Nanostructures: Structural, Optical, and Thermal Characterization

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RAJESH, P. NAGARANI SOBANA This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4580952/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 3 You are reading this latest preprint version Abstract Semiconducting tin oxide (SnO 2 ) nanostructures were successfully synthesized using a simple, rapid, and energy-saving microwave-assisted technique. The prepared SnO 2 samples were characterized by XRD, TEM, EDX, UV–DRS, photoluminescence, and TGA/DTA, demonstrating good crystal quality. The structure and surface morphology of the samples were investigated as a function of microwave irradiation using X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). Structural studies by XRD revealed that the samples exhibit a tetragonal cassiterite structure, with a crystallite size observed to vary from 2 to 23 nm according to TEM measurements. UV-VIS diffuse reflectance spectroscopy (DRS) indicated that the direct and indirect band gap energies of SnO 2 are 3.86 and 1.56 eV, respectively. To highlight the optical properties of the SnO 2 nanostructures, the variation of photon energy concerning microwave radiation was investigated through absorption and extinction coefficient studies, refractive index, dielectric constant, and optical conductivity studies. The SnO 2 nanoparticles exhibited emission peaks at 428, 484, 525, and 632 nm in the photoluminescence spectrum. The major weight loss observed in thermo gravimetric analysis and differential thermal analysis (TGA/DTA) corresponds to the formation of tin oxide. Tin oxide chemical synthesis Microwave technique nanostructures optical property Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 1. Introduction Nanotechnology involves the design, fabrication, and application of nanostructures or nanomaterials, coupled with a fundamental understanding of the relationship between physical properties or phenomena and material dimensions. It deals with materials or structures at nanometre scales, typically ranging from subnanometres to several hundred nanometres. The optical properties of nanocrystalline semiconductors have been extensively studied in recent years to translate their enhanced properties into practical applications. As the size of the material decreases, the band gap increases (band gaps of semiconductors can be tuned by varying material dimensions), thereby altering the optical and electrical properties of the material and rendering it suitable for new applications and devices [ 1 ]. The optical properties of semiconducting metal oxide nanoparticles have recently garnered significant interest. Tin oxide (SnO 2 ) is a versatile wide-bandgap (3.6 eV at 300K) n-type semiconducting oxide with a wide range of applications. Due to its electrical and optical properties (transparent for visible light and reflective for IR) [ 2 ], coupled with good chemical and mechanical stability [ 3 ], it is commonly employed in various applications such as oxidation catalysis [ 4 ], gas sensing [ 5 – 7 ], transparent conducting oxides [ 8 , 9 ], and optoelectronic devices [ 10 , 11 ]. The fabrication of SnO 2 nanostructures can be achieved using various methods such as ion sputtering [ 12 ], sol–gel [ 13 ], reverse cell [ 14 ], thermal evaporation [ 15 ], and surfactants mediated techniques [ 16 ]. This work is a continuation of our focus on synthesizing tin oxide using a microwave-assisted technique due to its increased reaction rate, more uniform temperature, moisture profiles, improved yields, and enhanced product performance [ 17 ]. In this present study, we report on the structural, thermal, and optical properties, including the optical band gap and optical constants such as absorption & extinction coefficient, refractive index, dielectric constant, and optical conductivity of the samples, utilizing UV-DRS spectrum with exposure to microwave irradiation. Feng Gu et al.[ 18 ], A.Y. El-Etre et al. [ 19 ], M. Parthibavarman et al. [ 20 ], Ganesh E Patil et al. [ 21 ] have reported the band gap values of tin oxide nanoparticles using various methods involving high-temperature treatment and significant time requirements (i.e., high energy consumption). However, the present method produces high-quality crystalline SnO 2 nanostructures and fine optical properties in just 5–15 minutes with low energy consumption. To the best of our knowledge, there is no reported data on the band gap and optical constant measurements of the SnO 2 samples with exposure to microwave irradiation at different time intervals. 2. Experimental 2.1 Synthesis To prepare SnO 2 , a 0.1M precursor solution of Stannous Chloride (SnCl 2 ·2H 2 O) was prepared separately. Subsequently, ammonia solution (NH 4 OH) was added to the prepared solution. The resulting mixture was stirred at room temperature until the pH reached 8. The resulting precipitate was washed with double-distilled water until no chlorine ions were detected in the silver nitrate test. The obtained precipitate was then placed in a microwave oven (2.45GHz, 800W) and irradiated for 5 minutes (Sample-A), 10 minutes (Sample-B), and 15 minutes (Sample-C), followed by drying at 120°C in a conventional oven. 2.2 Characterization The crystalline structure of the samples was analyzed by X-ray diffraction (XRD) using a Bruker AXSD8 Advance instrument with the CuKα wavelength of 1.5406 Å. The average crystalline size of the crystallites was evaluated using Scherrer’s formula, where d represents the mean crystalline size, k is a grain shape-dependent constant (0.9), λ is the wavelength of the incident beam, θ is the Bragg reflection angle, and β is the full width half maximum. TEM analysis was performed using a Philips instrument, Model CM12, operating at 120 kV and directly interfaced with a computer for real-time image processing. EDX analysis was conducted with a JEOL 5600LV microscope at an accelerating voltage of 10 kV. The DRS reflectance spectra were studied using UV–DRS absorption spectroscopy - Specord S600-212C205 UV Spectrophotometer. Photoluminescence spectrum analysis was carried out using a Spectrofluorometer - Fluorolog-FL3-11. Thermal stability of the sample was examined using a TGDSC Netzsch Modello STA409PC apparatus under a N2 atmosphere. 3. Results and Discussion 3.1Materials characterization The characteristic XRD spectra of the microwave-irradiated tin oxide samples A (5 min), B (10 min), and C (15 min) are shown in Fig. 1 (a, b, c). The peak positions of each sample exhibit the tetragonal Cassiterite structure of SnO 2 and the following Miller indices: [110], [101], [200], [211], [220], [310], [112], [301], [202], and [321], which were very well matched with the standard JCPDS card #41–1445 without any characteristic peaks of impurities, confirming the single-phase formation of the material. The average crystallite size of the SnO 2 samples was calculated using the Scherrer equation Crystallite Size = 0.9 λ / β cosθ. where λ is the wavelength of the incident X-ray radiation, θ is the usual Bragg angle, and β is the full width at half-maxima (FWHM) of a diffraction peak. The determined average size of the as-prepared SnO2 was found to be 19 to 24 nm. By increasing the duration of microwave radiation on tin hydroxide solution, the average crystallite size gradually decreases, as shown in Fig. 2 . Microwave treatment reduces the particle size and increases the homogeneity of the materials. This is due to the enhanced surface enrichment when thermal agitation of liquid molecules occurs in the microwave field. The apparent change in the material yields improvement, resulting in the evolution of new material phases. Microwave treatment is thus a rapid approach that has the capability to control the particle shape and size. It was concluded that microwave treatment improved the crystalline structure. The lattice parameters of the SnO 2 crystals for samples A, B, and C were calculated as a = 4.7380 Å, 4.7369 Å, 4.7343 Å, and c = 3.3502 Å, 3.3494 Å, 3.3475 Å, respectively, which match well with the standard values of (a = 4.7382 Å, c = 3.1871 Å) for SnO 2 crystals. Accordingly, some XRD parameters, such as the dislocation density (δ) and the strain (ε), to obtain more information about the structure properties of microwave-assisted tin oxide nanoparticles, can be determined using the following equations δ = n/D 2 , ε = (β cos θ)/4 where n is a factor, equal to unity gives the minimum dislocation density, D is the average crystallite size, β is the full width at half-maxima (FWHM), and θ is the Bragg angle. The values of dislocation density (δ) and strain (ε) of (110), (101), and (211) planes for microwave-assisted tin oxide samples are given in Table 1. The number of dislocation lines per unit area inside nanoparticles decreases with the increase of crystallite size In order to investigate the surface morphology and particle size behind the formation of SnO 2 nanostructures, TEM analysis was performed as shown in Fig. 3 (A, C, E). The TEM micrograph of sample-A (Fig. 3 A) shows the presence of less-agglomerated, spherical-shaped morphology of tin oxide nanostructures. The TEM micrograph for sample-B and sample-C (Fig. 3 C & E) shows the presence of irregularly shaped nanostructures, which are composed of small nanoparticles. The particle size observed from the TEM micrograph for samples A, C, and E ranges from 2 to 23 nm. The particle size observed from the TEM micrograph is well-matched with the average crystalline size calculated from the XRD pattern. This result reveals the formation of single-crystalline SnO 2 nanostructures. The compositional analysis of the samples was confirmed by EDX analysis. The EDX spectra of samples A, B, and C are shown in Fig. 3 (B, D, F). The Sn (L1, Lα, Lb, Lb2, Lr, Lr2) and O (Kα) peaks are only present in the EDX spectra, confirming that the synthesized SnO 2 samples have a pure form without any impurities. 3.2 Optical characterization UV-DRS measurements were conducted at room temperature in the range of 200–2000 nm to gather information on the optical properties of SnO 2 nanoparticles obtained at different time exposures of microwave-radiated samples A, B, and C. The variation of reflectance (R) of SnO 2 nanoparticles with respect to wavelength (λ) is depicted in Fig. 4 . As shown in Fig. 4 , the reflectance of the nanostructures increases in the visible range (up to 957 nm) and then decreases with increasing wavelength. The maximum reflectance (50.16% at 957 nm) for sample B is evident in Fig. 4 . In order to determine the precise value of the optical bandgap of SnO 2 , the reflectance values were converted to absorbance using the Kubelka-Munk function [ 26 , 27 ]. The Kubelka-Munk theory is commonly employed for the analysis of diffuse reflectance spectra obtained from weakly absorbing samples. The Kubelka-Munk formula is expressed by the following relation: $$F\left({\text{R}}_{{\infty }}\right)=\frac{{\left(1-{R}_{{\infty }}\right)}^{2}}{2{R}_{{\infty }}}=\frac{k}{S}=\frac{Ac}{S}$$ F(R ∞ ) is the so-called remission or Kubelka–Munk function, where R ∞ is defined as R sample /R standard . Here, k represents the absorption coefficient, S is the scattering coefficient, c is the concentration of the absorbing species, A is the absorbance, and R is the reflectance. Optical transitions in semiconductor materials are known to occur through both direct and indirect processes. A graph was plotted between [F(R ∞ )hν]n and hν, where n is a constant determining the type of optical transition: for n = 2, an indirect allowed transition, and for n = ½, a direct allowed transition. The curve of [F(R ∞ )hν] 2 and [F(R ∞ )hν] 1/2 vs hν for SnO 2 samples A, B, and C was plotted [ 28 ], as shown in Fig. 5 (a&b). Optical bandgap values for SnO 2 samples were obtained by extrapolating to the linear portions of these plots to the x-axis (photon energy), i.e., hν = 0. The values were found to be 3.86 eV (321 nm) and 1.56 eV (796 nm) for direct and indirect transitions, respectively. These obtained bandgap values are in good agreement with reported values [ 29 – 32 ] from various techniques such as those by Ganesh E Patil et al, Arham S. Ahmed et al, Hongmei Deng et al, M.Parthibavarman et al, who obtained bandgap values of 3.6 eV (at 100°C for 12 h), 3.9 eV (at 120°C for 15 h), 3.97 eV (at 500°C), and 3.56 eV (at 500°C for 5 h) for SnO 2 samples. However, in the present work, the energy gap value of 3.86 eV for SnO 2 was obtained using the microwave irradiation technique in just 5–15 minutes. The bandgap value obtained is higher than the reported value of the bulk SnO 2 (3.6 eV) [ 33 ], which can be attributed to the quantum confinement effect of the nanoparticles [ 34 ]. The synthesized samples exhibit strong crystallinity, supporting quantum size effects. We found that the band gap energy value remains constant irrespective of the microwave radiation exposure. It can be suggested that by varying the methods, the bandgap value may be altered. The refractive index (n) and extinction coefficient (k) of SnO 2 samples (A, B, C) can be determined using the following relationships [ 35 , 36 ] $$n=\left(\frac{1+R}{1-R}\right)+{\left(\frac{4R}{{(1-R)}^{2}}\right)}^{1/2}$$ $$k=\frac{\alpha \lambda }{4\pi }$$ In the presented study, the refractive index (n) is determined in relation to the diffused reflectance (R) for the investigated SnO 2 nanostructure samples denoted as A, B, and C. Figure 6 illustrates the dependence of the refractive index on the wavelength, specifically for SnO 2 nanostructure samples A, B, and C, which underwent different time intervals of microwave irradiation. Within the visible region, the refractive index (n) exhibits variations ranging from 5.73688 to 2.03486. As depicted in the figure, the refractive index of all samples (A, B, and C) consistently increases with wavelength, reaching a maximum value before gradually decreasing with further increases in wavelength. Notably, sample B demonstrates a maximum refractive index of 5.79 at 961 nm, while samples A and C exhibit peaks of 5.59 and 5.12 at 898 nm, respectively. This observed behaviour is attributed to the significant influence of electronic transitions occurring during different time intervals of microwave radiation, leading to substantial changes in the optical parameters. The systematic elevation of the refractive index with increasing photon energy suggests a normal dispersion preceding the absorption edge, followed by an anomalous dispersion. This trend underscores the intricate relationship between microwave irradiation duration and the resultant optical characteristics of the SnO 2 nanostructure samples. The absorption coefficient reflects a material's ability to absorb light, and Fig. 7 (a) demonstrates the variation of optical absorbance with energy. The calculated absorption coefficient values are on the order of 10 2 cm − 1 . Notably, Fig. 7 (a) reveals a decrease in absorbance up to 1.24 eV, followed by an increase with the rise of photon energy. The figure records maximum absorbance at 723 cm − 1 for sample C and a minimum of 229 cm − 1 for sample B. Figure 7 (b) highlights the range of changes in the extinction coefficient (k), which spans from 0.00012148 to 0.000803755. The values of k exhibit a linear increase with the augmentation of photon energy across all microwave-irradiated samples. The extinction coefficient's inverse relation with transmittance spectra is evident, with lower values indicating higher transmittance for the samples. This observation suggests the potential for high optical transmittance in the investigated microwave-irradiated SnO 2 samples. The fundamental electron excitation spectrum of these samples is elucidated through the frequency dependence of the complex electronic dielectric constant, defined as ε(ω) = ε₁(ω) + iε₂(ω), where the real (ε₁) and imaginary (ε₂) parts are intricately linked to the refractive index (n) and extinction coefficient (k). The values of ε₁ and ε₂ were computed using the formulas [ 37 , 38 ]. $${\epsilon }_{1}={n}^{2 }-{k}^{2 }$$ $${\epsilon }_{2}=2nk$$ These calculations provide a comprehensive understanding of the electronic properties of SnO 2 samples A, B, and C, contributing valuable insights into their optical behaviour. The real (ε₁) and imaginary (ε₂) parts of the dielectric constant play a crucial role in understanding the electronic properties of microwave-irradiated SnO 2 samples A, B, and C. Their variations with photon energy are presented in Fig. 8 (a&b). In Fig. 8 (a), the real part of the dielectric constant exhibits an increase up to 1.27 eV of photon energy, followed by a subsequent decrease with increasing wavelength. Concurrently, Fig. 8 (b) illustrates the behaviour of the imaginary part of the dielectric constant, which decreases with increasing wavelength. Both the real and imaginary parts of the dielectric constants exhibit a similar trend, with the real part consistently higher than the imaginary part. The observed variations in the dielectric constant, particularly the increase in the real part with photon energy, suggest the occurrence of interactions between photons and electrons within this energy range. These quantities are instrumental in calculating the rate of energy loss for electrons traversing through the material. The presented data in Fig. 8 contributes to a comprehensive understanding of the dynamic electronic interactions in the microwave-irradiated SnO 2 samples. The optical conductivity components, σ₁ and σ₂, are defined as σ₁ = ωε₂ε₀ and σ₂ = ωε₁ε₀, where ω is the angular frequency, and ε₀ is the free space dielectric constant. The wavelength-dependent behaviour of both real and imaginary parts of the optical conductivity is illustrated in Fig. 9 (a&b). Upon closer analysis, the real part of the optical conductivity demonstrates different trends in two distinct wavelength regions: below 820 nm and above 820 nm. For wavelengths less than 820 nm, the real part decreases with increasing wavelength, while the imaginary part increases. Conversely, for wavelengths exceeding 820 nm, the real part increases with the wavelength, while the imaginary part decreases. This dual behaviour in the higher wavelength region is attributed to interactions between photons and electrons. The presented data in Fig. 9 offers insights into the complex interplay of optical conductivity components, shedding light on the material's response to varying wavelengths. The room temperature Photoluminescence (PL) behaviours of nanostructure SnO 2 samples A, B, and C were investigated using a Spectro fluorometer within the range of 410–680 nm, with results presented in Fig. 10 . The photoluminescence spectrum was recorded utilizing a 385 nm excitation source. Observing the PL spectra, all samples (A, B, and C) exhibit a pronounced emission band at 484 nm, accompanied by weaker emission bands at 428 nm, 525 nm, and 632 nm. These bands are associated with different charge states of oxygen vacancies, such as Vo⁰, Vo⁺, and Vo⁺⁺. Photo-excitation of SnO 2 may result in the trapping of holes at the Vo⁺ centre, leading to the formation of Vo⁺⁺ centres, as indicated by the emission peak around 400 nm [ 40 , 41 ]. The emission at 428 nm is attributed to residual stresses within the tin dioxide nanocrystals, originating from lattice distortion [ 42 ]. The prominent emission peak at 484 nm is linked to blue luminescence in SnO 2 , primarily caused by oxygen-related defects introduced during the growth process [ 43 ]. The peaks at 525 nm and 632 nm are associated with V O ⁺ oxygen vacancies [ 44 ]. Remarkably, despite exposure to microwave radiation, all three samples emit similar radiations, suggesting that the mechanism driving the blue emission is primarily influenced by the concentration of free electrons and the presence of various identified point defects, including Vo. 3.2 Thermal characterization Thermogravimetric analysis (TGA) of microwave-synthesized tin oxide was conducted to assess weight loss under N 2 atmosphere, as depicted in Fig. 11 . The observed weight loss profile provides insights into various processes occurring within the sample. Between 30°C and 250°C, a weight loss of approximately 1.249% is noted. This initial loss is attributed to the elimination of ammonia, physically absorbed water, and chemically bonded water, manifested by an endothermic peak [ 17 ]. Subsequently, from 250°C to 600°C, a weight loss of 6.360% occurs, corresponding to desorption and decomposition of the surfactant template. The final weight loss, around 4.895% between 600°C and 860°C, is linked to dihydroxylation on the surface and the removal of residual surfactant [ 45 ]. The Differential Thermal Analysis (DTA) results align with the TGA findings, revealing broad peaks from 250°C to 600°C and 600°C to 860°C, indicative of residual surfactant presence in these temperature ranges. The combined TGA and DTA analyses offer a comprehensive understanding of the thermal behaviour and decomposition processes involved in the microwave-synthesized tin oxide. The current study presents an exploration of the optical properties of SnO 2 nanostructures under the influence of microwave radiation. The optical characteristics of SnO 2 , such as its band gap (e.g., 3.6 eV for bulk materials), have traditionally been obtained through various techniques that often require prolonged exposure times and substantial energy consumption, particularly due to the necessity for high-temperature treatment. In contrast, our approach involves the rapid synthesis of SnO 2 nanostructures within a remarkably short timeframe of 5–15 minutes using microwave radiation, and notably, without the addition of any surfactants or chemical agents. Microwave heating facilitates instant volumetric heating, resulting in a significantly accelerated process compared to conventional heating methods. This accelerated sintering kinetics, enabled by microwave radiation, allows for a reduction in both temperature and processing time, thereby increasing productivity and minimizing energy consumption [ 46 ]. This innovative method not only offers efficiency in synthesis but also underscores the potential for sustainable and energy-conscious fabrication of SnO 2 nanostructures. 4. Conclusion The synthesis of SnO 2 nanostructures was successfully achieved through a microwave-assisted technique, enabling a comprehensive investigation of their structural, optical, and thermal properties. The XRD pattern confirmed a Cassiterite-type tetragonal structure, with a crystallite size of 19–24 nm, as determined by both XRD and TEM analyses. The EDX spectrum affirmed the formation of pure SnO 2 without any impurities. The optical properties, including direct and indirect band gaps (3.86 and 1.56 eV, respectively), and various optical constants (refractive index, absorbance, extinction coefficient, real and imaginary parts of the dielectric constant, and optical conductivity), were determined through UV-DRS. Photoluminescence analysis revealed a strong blue emission peak at 484 nm. Thermal analysis via TGA/DTA provided insights into the material's thermal behaviour. Importantly, microwave radiation at different time intervals demonstrated no adverse effects on the optical properties. This method allows for the rapid synthesis of SnO 2 nanostructures within a short duration, reducing energy consumption, enhancing crystal quality, and yielding fine optical properties. The approach was found to be a convenient, mild, and efficient route for the controlled synthesis of tin oxide nanostructures. Proposing this synthesis method for optoelectronic applications underscores its potential for practical use in various technological domains. Declarations Acknowledgments: I would like to express my deepest gratitude to my family for their unwavering support and encouragement. To my parents, for their endless love and guidance. To my brother, for always being there for me. To my wife, for her patience, understanding, and support. To my daughter, for her joy and inspiration. Your constant encouragement, motivation and support has been invaluable throughout this journey. Author contributions: Author 1: Dr.N.RAJESH (Corresponding author) Conceived and designed the analysis Collection of data Contributed data analysis Wrote the paper Author 2: P.NAGARANI SOBANA (Co-author) Data interpretation System work Plotting graph Conflicts of interest or competing interests: Not Applicable Data and code availability: Not Applicable Supplementary information: Not Applicable Ethical approval: Not Applicable References Ameer Azam, Arham S. Ahmed, Sami S. Habib, A.H. Naqvi (2012) Effect of Mn doping on the structural and optical properties of SnO 2 nanoparticles. J Alloys Compd 523:83– 87. https://doi.org/10.1016/j.jallcom.2012.01.072. S.D.Monredon, A. Cellot, F. Ribot, C. Sanchez, L.D. Armelao, L.Guanean, L. Delattre (2002) Synthesis and characterization of crystalline tin oxide nanoparticles. J Mater Chem 12:2396 - 2400. https://doi.org/10.1039/B203049G K.L.Chopra, S.Major, D.K.Pandya (1983) Transparent conductors—A status review. 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Zhu, C.M. Liu, L.M. Wang, F. Gao, Microstructure and luminescence properties of Co-doped SnO 2 nanoparticles synthesized by hydrothermal method (2008) J Mater Sci Mater Electron 19:868 – 874. 10.1007/s10854-007-9543-7 T. Takagahara, K. Takeda (1992) Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials, Phys Rev B 46:15578 - 15581. https://doi.org/10.1103/PhysRevB.46.15578 C. Aydın, Omar A, Al-Hartomy, A. A. Al-Ghamdi, F. Al-Hazmi, I. S. Yahia, F. El-Tantawy, F. Yakuphanoglu (2012) Controlling of crystal size and optical band gap of CdO nanopowder semiconductors by low and high Fe contents, J Electroceram 29:155–162. 10.1007/s10832-012-9748-x Salih Kose, Ferhunde Atay, Vildan Bilgin, Idris Akyuz (2009) In doped CdO films: Electrical, optical, structural and surface properties, Int J Hydrogen Energy 34:5260 – 5266. 10.1016/j.ijhydene.2008.11.110 A.K. Wolaton, T.S. Moss (1963) Determination of Refractive Index and Correction to Effective Electron Mass in PbTe and PbSe, Proc R Soc 81:509-513. Mujdat Caglar, Saliha Ilican, Yasemin Caglar, Fahrettin Yakuphanoglu (2009) Electrical conductivity and optical properties of ZnO nanostructured thin film, App Surf Sci 255:4491–4496. https://doi.org/10.1016/j.apsusc.2008.11.055 J.N. Hodgson (1970) Optical Absorption and Dispersion in Solids, Chapman and Hall LTD, 11 New fetter Lane London EC4. Fahrettin Yakuphanoglu, Saliha Ilican, Mujdat Caglar, Yasemin Caglar (2010) Microstructure and electro-optical properties of sol gel derived Cd-doped ZnO films, Superlattices. Microstruct, 47:732-743. https://doi.org/10.1016/j.spmi.2010.02.006 M.A. Gondal, Q.A. Drmosh, T.A. Saleh (2010) Preparation and characterization of SnO 2 nanoparticles using high power pulsed laser, App Surf Sci 256:7067–7070. 10.1016/j.apsusc.2010.05.027 F. Gu, S.F. Wang, M.K. Lu, X.F. Cheng, S.F. Liu, G.J. Zhou, X. Dong, D.R. Yuan (2004) Luminescence of SnO 2 thin films prepared by spin-coating method, J Cryst Growth 262:182–185. https://doi.org/10.1016/j.jcrysgro.2003.10.028 Y. Her, J. Wu, Y.R. Lin, S.Y. Tsai (2006) Low-temperature growth and blue luminescence of SnO 2 nanoblades, Appl Phys Lett 89:043115-043123. 10.1063/1.2235925 J.X. Zhou, M.S. Zhang, J.M. Hong, Z. Yin (2006) Raman spectroscopic and photoluminescence study of single-crystalline SnO 2 nanowires, Solid State Commun, 138 :242–246. https://doi.org/10.1016/j.ssc.2006.03.007 Yude Wang, chunlai Ma, Xiaodan Sun, Hengde Li (2001) Synthesis of mesoporous structured material based on tin oxide, Micropor. Mesopor. Mat. 49:171-178. 10.1016/S1387-1811(01)00415-2 Avijit Mondal, Dinesh Agrawa, Anish Upadhyaya (2009) Microwave Heating of Pure Copper Powder with Varying Particle Size and Porosity, J Microw Power Electromagn Energy 43:5-10. 10.1080/08327823.2008.11688599. Table 1 Table.1 Values of crystallite size D, strain ε and the dislocation density δ of microwave assisted tin oxide nanostructures samples Sample Microwave irradiation (min) The average crystallite size (nm) The dislocation density δ×10 15 (lines/m 2 ) The strain ε × 10 −3 (110) (101) (211) SnO 2 5 24 1.7361 77.8567 119.5826 224.9465 10 21 2.2675 87.5879 90.8890 76.4766 15 19 2.77 80.2860 93.2729 98.9672 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editor assigned by journal 18 Jun, 2024 Submission checks completed at journal 18 Jun, 2024 First submitted to journal 14 Jun, 2024 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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-4580952","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":316082049,"identity":"4c70b453-fcd0-4342-aaa2-99062fd8f92d","order_by":0,"name":"N. RAJESH","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA/ElEQVRIiWNgGAWjYHCCBAbGhgQQg/HhhwogxczcQLQWZmOJMyCKkaAWBpgWNgneNggXr2rz9gMPH/7ckSZvPiP3sYHkvNpo/naglh8V23BqkTmTkGzMeybHcM6NdMMHhduO5844zNjA2HPmNk4tEgwJadKMbRWMMyTSmA0ktx3LbQBqYWZsw6OF/0H6z59tFfZALUC/zDmWO5+gFomENAbetpxEiJaGmtwNhLU8SJbmbUtLnsHzDBjIxw7kbgRqOYjXL/w5iR9/tiXbzmBPA0ZlTV3uvPOHDz74UYFbCwMDTwIy7zCYPIBHPRCwo8jX4Vc8CkbBKBgFIxIAAKWmWyuz7MTEAAAAAElFTkSuQmCC","orcid":"","institution":"Government Polytechnic College","correspondingAuthor":true,"prefix":"","firstName":"N.","middleName":"","lastName":"RAJESH","suffix":""},{"id":316082054,"identity":"52174ef5-4bed-4f6d-8074-3cfcf1038c3d","order_by":1,"name":"P. NAGARANI SOBANA","email":"","orcid":"","institution":"Chettinad College of Engineering and Technology","correspondingAuthor":false,"prefix":"","firstName":"P.","middleName":"NAGARANI","lastName":"SOBANA","suffix":""}],"badges":[],"createdAt":"2024-06-14 09:20:25","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4580952/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4580952/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":60428727,"identity":"8a1661c7-bb3b-4470-9552-e54885c55658","added_by":"auto","created_at":"2024-07-16 15:58:48","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":19504,"visible":true,"origin":"","legend":"\u003cp\u003eXRD pattern of microwave radiated samples A, B \u0026amp; C\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/7e7670c163c16e8a2b1de6d3.png"},{"id":60429683,"identity":"7c54b9cd-c0e4-4b25-9f6f-2cf0e61dccab","added_by":"auto","created_at":"2024-07-16 16:06:48","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":9131,"visible":true,"origin":"","legend":"\u003cp\u003eRelationship between microwave radiation time and average crystalline size\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/dc2718dabf7172974b07f60f.png"},{"id":60429682,"identity":"29e9eea6-64f7-4ca9-a31c-bef3a32fa76f","added_by":"auto","created_at":"2024-07-16 16:06:48","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1845655,"visible":true,"origin":"","legend":"\u003cp\u003eTEM images (A,C,E) and corresponding EDX spectra (B,D,F) of the samples A,B \u0026amp; C\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/82070f0ae68e2ffb7250163a.png"},{"id":60428719,"identity":"d2218252-15bc-40ca-985a-e66cc4fe5617","added_by":"auto","created_at":"2024-07-16 15:58:48","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":103683,"visible":true,"origin":"","legend":"\u003cp\u003eDiffused reflectance spectrum as a function of wavelength for SnO\u003csub\u003e2 \u003c/sub\u003esamples A, B \u0026amp; C\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/cd00e9f487ad03806cfd738d.png"},{"id":60429685,"identity":"a85ff28d-f3eb-4045-bf0f-1b02333fae5a","added_by":"auto","created_at":"2024-07-16 16:06:48","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":155043,"visible":true,"origin":"","legend":"\u003cp\u003e(a) and (b) represent the plots of [F(R∞)hυ]² and [F(R∞)hυ](1/2), respectively, against the photon energy for SnO2 samples A, B, and C.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/1ef85d84cc95f59513e7e04b.png"},{"id":60430061,"identity":"d3eb2cb2-4fed-480a-ab0d-90c4e532d984","added_by":"auto","created_at":"2024-07-16 16:14:48","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":110454,"visible":true,"origin":"","legend":"\u003cp\u003eWavelength Dependent variation of Refractive index for SnO\u003csub\u003e2\u003c/sub\u003e samples A, B and C\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/a297048ae7b0cc0bbe2380e6.png"},{"id":60430062,"identity":"b63edd9b-84ac-4a1c-9ce9-216a2ddcfd06","added_by":"auto","created_at":"2024-07-16 16:14:48","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":148137,"visible":true,"origin":"","legend":"\u003cp\u003e(a \u0026amp; b) presents the variation of the absorption coefficient (α) and extinction coefficient (k) concerning incident photon energy (hν) and wavelength (λ) for SnO\u003csub\u003e2\u003c/sub\u003e samples A, B, and C.\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/3ed6bb3ee30c5edc482dd11e.png"},{"id":60428720,"identity":"754327cf-d579-495e-8810-6475a86980f0","added_by":"auto","created_at":"2024-07-16 15:58:48","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":133032,"visible":true,"origin":"","legend":"\u003cp\u003eVariation of the real part (a) and imaginary part (b) of the dielectric constant with photon energy for samples A, B, and C.\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/580801facbc2fd6926a12157.png"},{"id":60428724,"identity":"1ab882e1-3d5f-42c8-b448-681a76fb8892","added_by":"auto","created_at":"2024-07-16 15:58:48","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":158815,"visible":true,"origin":"","legend":"\u003cp\u003eVariation of real part (a) and imaginary part (b) of optical conductivity with wavelengths for samples A, B and C\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/39ced8aca27288dc54e0cd0e.png"},{"id":60428721,"identity":"37e117b7-8414-488c-929b-d1b4b98056b4","added_by":"auto","created_at":"2024-07-16 15:58:48","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":146699,"visible":true,"origin":"","legend":"\u003cp\u003ePhotoluminescence spectra of SnO\u003csub\u003e2\u003c/sub\u003e samples A, B and C\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/afd6fe8324c5ddd3d8262c89.png"},{"id":60428722,"identity":"da8951b1-e772-409b-bd29-48f25c9711cf","added_by":"auto","created_at":"2024-07-16 15:58:48","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":120984,"visible":true,"origin":"","legend":"\u003cp\u003eTGA and DTA spectra of Tin oxide in N\u003csub\u003e2\u003c/sub\u003e atmosphere\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/5a7adf2dbda6467884c4a18c.png"},{"id":60430545,"identity":"ec387ff2-b91e-4a86-9a0f-bff88f00d46c","added_by":"auto","created_at":"2024-07-16 16:22:52","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3856843,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4580952/v1/16d2ea85-ef54-4aee-abd8-ebda52b11cef.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Microwave-Assisted Synthesis and Evaluation of SnO 2 Nanostructures: Structural, Optical, and Thermal Characterization","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eNanotechnology involves the design, fabrication, and application of nanostructures or nanomaterials, coupled with a fundamental understanding of the relationship between physical properties or phenomena and material dimensions. It deals with materials or structures at nanometre scales, typically ranging from subnanometres to several hundred nanometres. The optical properties of nanocrystalline semiconductors have been extensively studied in recent years to translate their enhanced properties into practical applications. As the size of the material decreases, the band gap increases (band gaps of semiconductors can be tuned by varying material dimensions), thereby altering the optical and electrical properties of the material and rendering it suitable for new applications and devices [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. The optical properties of semiconducting metal oxide nanoparticles have recently garnered significant interest. Tin oxide (SnO\u003csub\u003e2\u003c/sub\u003e) is a versatile wide-bandgap (3.6 eV at 300K) n-type semiconducting oxide with a wide range of applications. Due to its electrical and optical properties (transparent for visible light and reflective for IR) [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], coupled with good chemical and mechanical stability [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], it is commonly employed in various applications such as oxidation catalysis [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], gas sensing [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], transparent conducting oxides [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], and optoelectronic devices [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe fabrication of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures can be achieved using various methods such as ion sputtering [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], sol\u0026ndash;gel [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], reverse cell [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], thermal evaporation [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], and surfactants mediated techniques [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. This work is a continuation of our focus on synthesizing tin oxide using a microwave-assisted technique due to its increased reaction rate, more uniform temperature, moisture profiles, improved yields, and enhanced product performance [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In this present study, we report on the structural, thermal, and optical properties, including the optical band gap and optical constants such as absorption \u0026amp; extinction coefficient, refractive index, dielectric constant, and optical conductivity of the samples, utilizing UV-DRS spectrum with exposure to microwave irradiation. Feng Gu et al.[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], A.Y. El-Etre et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], M. Parthibavarman et al. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], Ganesh E Patil et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] have reported the band gap values of tin oxide nanoparticles using various methods involving high-temperature treatment and significant time requirements (i.e., high energy consumption). However, the present method produces high-quality crystalline SnO\u003csub\u003e2\u003c/sub\u003e nanostructures and fine optical properties in just 5\u0026ndash;15 minutes with low energy consumption. To the best of our knowledge, there is no reported data on the band gap and optical constant measurements of the SnO\u003csub\u003e2\u003c/sub\u003e samples with exposure to microwave irradiation at different time intervals.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1 Synthesis\u003c/h2\u003e \u003cp\u003eTo prepare SnO\u003csub\u003e2\u003c/sub\u003e, a 0.1M precursor solution of Stannous Chloride (SnCl\u003csub\u003e2\u003c/sub\u003e\u0026middot;2H\u003csub\u003e2\u003c/sub\u003eO) was prepared separately. Subsequently, ammonia solution (NH\u003csub\u003e4\u003c/sub\u003eOH) was added to the prepared solution. The resulting mixture was stirred at room temperature until the pH reached 8. The resulting precipitate was washed with double-distilled water until no chlorine ions were detected in the silver nitrate test. The obtained precipitate was then placed in a microwave oven (2.45GHz, 800W) and irradiated for 5 minutes (Sample-A), 10 minutes (Sample-B), and 15 minutes (Sample-C), followed by drying at 120\u0026deg;C in a conventional oven.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2 Characterization\u003c/h2\u003e \u003cp\u003eThe crystalline structure of the samples was analyzed by X-ray diffraction (XRD) using a Bruker AXSD8 Advance instrument with the CuKα wavelength of 1.5406 \u0026Aring;. The average crystalline size of the crystallites was evaluated using Scherrer\u0026rsquo;s formula, where d represents the mean crystalline size, k is a grain shape-dependent constant (0.9), λ is the wavelength of the incident beam, θ is the Bragg reflection angle, and β is the full width half maximum. TEM analysis was performed using a Philips instrument, Model CM12, operating at 120 kV and directly interfaced with a computer for real-time image processing. EDX analysis was conducted with a JEOL 5600LV microscope at an accelerating voltage of 10 kV. The DRS reflectance spectra were studied using UV\u0026ndash;DRS absorption spectroscopy - Specord S600-212C205 UV Spectrophotometer. Photoluminescence spectrum analysis was carried out using a Spectrofluorometer - Fluorolog-FL3-11. Thermal stability of the sample was examined using a TGDSC Netzsch Modello STA409PC apparatus under a N2 atmosphere.\u003c/p\u003e \u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e3.1Materials characterization\u003c/h2\u003e \u003cp\u003eThe characteristic XRD spectra of the microwave-irradiated tin oxide samples A (5 min), B (10 min), and C (15 min) are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e1\u003c/span\u003e(a, b, c). The peak positions of each sample exhibit the tetragonal Cassiterite structure of SnO\u003csub\u003e2\u003c/sub\u003e and the following Miller indices: [110], [101], [200], [211], [220], [310], [112], [301], [202], and [321], which were very well matched with the standard JCPDS card #41\u0026ndash;1445 without any characteristic peaks of impurities, confirming the single-phase formation of the material. The average crystallite size of the SnO\u003csub\u003e2\u003c/sub\u003e samples was calculated using the Scherrer equation Crystallite Size\u0026thinsp;=\u0026thinsp;0.9 λ / β cosθ. where λ is the wavelength of the incident X-ray radiation, θ is the usual Bragg angle, and β is the full width at half-maxima (FWHM) of a diffraction peak. The determined average size of the as-prepared SnO2 was found to be 19 to 24 nm.\u003c/p\u003e \u003cp\u003eBy increasing the duration of microwave radiation on tin hydroxide solution, the average crystallite size gradually decreases, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Microwave treatment reduces the particle size and increases the homogeneity of the materials. This is due to the enhanced surface enrichment when thermal agitation of liquid molecules occurs in the microwave field. The apparent change in the material yields improvement, resulting in the evolution of new material phases. Microwave treatment is thus a rapid approach that has the capability to control the particle shape and size. It was concluded that microwave treatment improved the crystalline structure.\u003c/p\u003e \u003cp\u003eThe lattice parameters of the SnO\u003csub\u003e2\u003c/sub\u003e crystals for samples A, B, and C were calculated as a\u0026thinsp;=\u0026thinsp;4.7380 \u0026Aring;, 4.7369 \u0026Aring;, 4.7343 \u0026Aring;, and c\u0026thinsp;=\u0026thinsp;3.3502 \u0026Aring;, 3.3494 \u0026Aring;, 3.3475 \u0026Aring;, respectively, which match well with the standard values of (a\u0026thinsp;=\u0026thinsp;4.7382 \u0026Aring;, c\u0026thinsp;=\u0026thinsp;3.1871 \u0026Aring;) for SnO\u003csub\u003e2\u003c/sub\u003e crystals. Accordingly, some XRD parameters, such as the dislocation density (δ) and the strain (ε), to obtain more information about the structure properties of microwave-assisted tin oxide nanoparticles, can be determined using the following equations δ\u0026thinsp;=\u0026thinsp;n/D\u003csup\u003e2\u003c/sup\u003e, ε = (β cos θ)/4 where n is a factor, equal to unity gives the minimum dislocation density, D is the average crystallite size, β is the full width at half-maxima (FWHM), and θ is the Bragg angle. The values of dislocation density (δ) and strain (ε) of (110), (101), and (211) planes for microwave-assisted tin oxide samples are given in Table\u0026nbsp;1. The number of dislocation lines per unit area inside nanoparticles decreases with the increase of crystallite size\u003c/p\u003e \u003cp\u003eIn order to investigate the surface morphology and particle size behind the formation of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures, TEM analysis was performed as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003e (A, C, E). The TEM micrograph of sample-A (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003eA) shows the presence of less-agglomerated, spherical-shaped morphology of tin oxide nanostructures. The TEM micrograph for sample-B and sample-C (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003eC \u0026amp; E) shows the presence of irregularly shaped nanostructures, which are composed of small nanoparticles. The particle size observed from the TEM micrograph for samples A, C, and E ranges from 2 to 23 nm. The particle size observed from the TEM micrograph is well-matched with the average crystalline size calculated from the XRD pattern. This result reveals the formation of single-crystalline SnO\u003csub\u003e2\u003c/sub\u003e nanostructures. The compositional analysis of the samples was confirmed by EDX analysis. The EDX spectra of samples A, B, and C are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e3\u003c/span\u003e (B, D, F). The Sn (L1, Lα, Lb, Lb2, Lr, Lr2) and O (Kα) peaks are only present in the EDX spectra, confirming that the synthesized SnO\u003csub\u003e2\u003c/sub\u003e samples have a pure form without any impurities.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Optical characterization\u003c/h2\u003e \u003cp\u003eUV-DRS measurements were conducted at room temperature in the range of 200\u0026ndash;2000 nm to gather information on the optical properties of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles obtained at different time exposures of microwave-radiated samples A, B, and C. The variation of reflectance (R) of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles with respect to wavelength (λ) is depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e4\u003c/span\u003e. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e4\u003c/span\u003e, the reflectance of the nanostructures increases in the visible range (up to 957 nm) and then decreases with increasing wavelength. The maximum reflectance (50.16% at 957 nm) for sample B is evident in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eIn order to determine the precise value of the optical bandgap of SnO\u003csub\u003e2\u003c/sub\u003e, the reflectance values were converted to absorbance using the Kubelka-Munk function [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The Kubelka-Munk theory is commonly employed for the analysis of diffuse reflectance spectra obtained from weakly absorbing samples. The Kubelka-Munk formula is expressed by the following relation:\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e\n$$F\\left({\\text{R}}_{{\\infty }}\\right)=\\frac{{\\left(1-{R}_{{\\infty }}\\right)}^{2}}{2{R}_{{\\infty }}}=\\frac{k}{S}=\\frac{Ac}{S}$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eF(R\u003csub\u003e\u0026infin;\u003c/sub\u003e) is the so-called remission or Kubelka\u0026ndash;Munk function, where R\u003csub\u003e\u0026infin;\u003c/sub\u003e is defined as R\u003csub\u003esample\u003c/sub\u003e/R\u003csub\u003estandard\u003c/sub\u003e. Here, k represents the absorption coefficient, S is the scattering coefficient, c is the concentration of the absorbing species, A is the absorbance, and R is the reflectance. Optical transitions in semiconductor materials are known to occur through both direct and indirect processes. A graph was plotted between [F(R\u003csub\u003e\u0026infin;\u003c/sub\u003e)hν]n and hν, where n is a constant determining the type of optical transition: for n\u0026thinsp;=\u0026thinsp;2, an indirect allowed transition, and for n = \u0026frac12;, a direct allowed transition. The curve of [F(R\u003csub\u003e\u0026infin;\u003c/sub\u003e)hν]\u003csup\u003e2\u003c/sup\u003e and [F(R\u003csub\u003e\u0026infin;\u003c/sub\u003e)hν]\u003csup\u003e1/2\u003c/sup\u003e vs hν for SnO\u003csub\u003e2\u003c/sub\u003e samples A, B, and C was plotted [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e5\u003c/span\u003e (a\u0026amp;b).\u003c/p\u003e \u003cp\u003eOptical bandgap values for SnO\u003csub\u003e2\u003c/sub\u003e samples were obtained by extrapolating to the linear portions of these plots to the x-axis (photon energy), i.e., hν\u0026thinsp;=\u0026thinsp;0. The values were found to be 3.86 eV (321 nm) and 1.56 eV (796 nm) for direct and indirect transitions, respectively. These obtained bandgap values are in good agreement with reported values [\u003cspan additionalcitationids=\"CR30 CR31\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] from various techniques such as those by Ganesh E Patil et al, Arham S. Ahmed et al, Hongmei Deng et al, M.Parthibavarman et al, who obtained bandgap values of 3.6 eV (at 100\u0026deg;C for 12 h), 3.9 eV (at 120\u0026deg;C for 15 h), 3.97 eV (at 500\u0026deg;C), and 3.56 eV (at 500\u0026deg;C for 5 h) for SnO\u003csub\u003e2\u003c/sub\u003e samples. However, in the present work, the energy gap value of 3.86 eV for SnO\u003csub\u003e2\u003c/sub\u003e was obtained using the microwave irradiation technique in just 5\u0026ndash;15 minutes.\u003c/p\u003e \u003cp\u003eThe bandgap value obtained is higher than the reported value of the bulk SnO\u003csub\u003e2\u003c/sub\u003e (3.6 eV) [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e], which can be attributed to the quantum confinement effect of the nanoparticles [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The synthesized samples exhibit strong crystallinity, supporting quantum size effects. We found that the band gap energy value remains constant irrespective of the microwave radiation exposure. It can be suggested that by varying the methods, the bandgap value may be altered.\u003c/p\u003e \u003cp\u003eThe refractive index (n) and extinction coefficient (k) of SnO\u003csub\u003e2\u003c/sub\u003e samples (A, B, C) can be determined using the following relationships [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e, \u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e\n$$n=\\left(\\frac{1+R}{1-R}\\right)+{\\left(\\frac{4R}{{(1-R)}^{2}}\\right)}^{1/2}$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equc\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equc\" name=\"EquationSource\"\u003e\n$$k=\\frac{\\alpha \\lambda }{4\\pi }$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eIn the presented study, the refractive index (n) is determined in relation to the diffused reflectance (R) for the investigated SnO\u003csub\u003e2\u003c/sub\u003e nanostructure samples denoted as A, B, and C. Figure\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e6\u003c/span\u003e illustrates the dependence of the refractive index on the wavelength, specifically for SnO\u003csub\u003e2\u003c/sub\u003e nanostructure samples A, B, and C, which underwent different time intervals of microwave irradiation. Within the visible region, the refractive index (n) exhibits variations ranging from 5.73688 to 2.03486. As depicted in the figure, the refractive index of all samples (A, B, and C) consistently increases with wavelength, reaching a maximum value before gradually decreasing with further increases in wavelength. Notably, sample B demonstrates a maximum refractive index of 5.79 at 961 nm, while samples A and C exhibit peaks of 5.59 and 5.12 at 898 nm, respectively. This observed behaviour is attributed to the significant influence of electronic transitions occurring during different time intervals of microwave radiation, leading to substantial changes in the optical parameters. The systematic elevation of the refractive index with increasing photon energy suggests a normal dispersion preceding the absorption edge, followed by an anomalous dispersion. This trend underscores the intricate relationship between microwave irradiation duration and the resultant optical characteristics of the SnO\u003csub\u003e2\u003c/sub\u003e nanostructure samples.\u003c/p\u003e \u003cp\u003eThe absorption coefficient reflects a material's ability to absorb light, and Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e7\u003c/span\u003e(a) demonstrates the variation of optical absorbance with energy. The calculated absorption coefficient values are on the order of 10\u003csup\u003e2\u003c/sup\u003e cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. Notably, Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e7\u003c/span\u003e(a) reveals a decrease in absorbance up to 1.24 eV, followed by an increase with the rise of photon energy. The figure records maximum absorbance at 723 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for sample C and a minimum of 229 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e for sample B. Figure\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e7\u003c/span\u003e(b) highlights the range of changes in the extinction coefficient (k), which spans from 0.00012148 to 0.000803755. The values of k exhibit a linear increase with the augmentation of photon energy across all microwave-irradiated samples. The extinction coefficient's inverse relation with transmittance spectra is evident, with lower values indicating higher transmittance for the samples. This observation suggests the potential for high optical transmittance in the investigated microwave-irradiated SnO\u003csub\u003e2\u003c/sub\u003e samples.\u003c/p\u003e \u003cp\u003eThe fundamental electron excitation spectrum of these samples is elucidated through the frequency dependence of the complex electronic dielectric constant, defined as ε(ω) = ε₁(ω)\u0026thinsp;+\u0026thinsp;iε₂(ω), where the real (ε₁) and imaginary (ε₂) parts are intricately linked to the refractive index (n) and extinction coefficient (k). The values of ε₁ and ε₂ were computed using the formulas [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e, \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003cdiv id=\"Equd\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equd\" name=\"EquationSource\"\u003e\n$${\\epsilon }_{1}={n}^{2 }-{k}^{2 }$$\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Eque\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Eque\" name=\"EquationSource\"\u003e\n$${\\epsilon }_{2}=2nk$$\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eThese calculations provide a comprehensive understanding of the electronic properties of SnO\u003csub\u003e2\u003c/sub\u003e samples A, B, and C, contributing valuable insights into their optical behaviour. The real (ε₁) and imaginary (ε₂) parts of the dielectric constant play a crucial role in understanding the electronic properties of microwave-irradiated SnO\u003csub\u003e2\u003c/sub\u003e samples A, B, and C. Their variations with photon energy are presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e8\u003c/span\u003e (a\u0026amp;b). In Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e8\u003c/span\u003e(a), the real part of the dielectric constant exhibits an increase up to 1.27 eV of photon energy, followed by a subsequent decrease with increasing wavelength. Concurrently, Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e8\u003c/span\u003e(b) illustrates the behaviour of the imaginary part of the dielectric constant, which decreases with increasing wavelength. Both the real and imaginary parts of the dielectric constants exhibit a similar trend, with the real part consistently higher than the imaginary part.\u003c/p\u003e \u003cp\u003eThe observed variations in the dielectric constant, particularly the increase in the real part with photon energy, suggest the occurrence of interactions between photons and electrons within this energy range. These quantities are instrumental in calculating the rate of energy loss for electrons traversing through the material. The presented data in Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e8\u003c/span\u003e contributes to a comprehensive understanding of the dynamic electronic interactions in the microwave-irradiated SnO\u003csub\u003e2\u003c/sub\u003e samples.\u003c/p\u003e \u003cp\u003eThe optical conductivity components, σ₁ and σ₂, are defined as σ₁ = ωε₂ε₀ and σ₂ = ωε₁ε₀, where ω is the angular frequency, and ε₀ is the free space dielectric constant. The wavelength-dependent behaviour of both real and imaginary parts of the optical conductivity is illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e9\u003c/span\u003e (a\u0026amp;b). Upon closer analysis, the real part of the optical conductivity demonstrates different trends in two distinct wavelength regions: below 820 nm and above 820 nm. For wavelengths less than 820 nm, the real part decreases with increasing wavelength, while the imaginary part increases. Conversely, for wavelengths exceeding 820 nm, the real part increases with the wavelength, while the imaginary part decreases. This dual behaviour in the higher wavelength region is attributed to interactions between photons and electrons. The presented data in Fig.\u0026nbsp;\u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e9\u003c/span\u003e offers insights into the complex interplay of optical conductivity components, shedding light on the material's response to varying wavelengths.\u003c/p\u003e \u003cp\u003eThe room temperature Photoluminescence (PL) behaviours of nanostructure SnO\u003csub\u003e2\u003c/sub\u003e samples A, B, and C were investigated using a Spectro fluorometer within the range of 410\u0026ndash;680 nm, with results presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e10\u003c/span\u003e. The photoluminescence spectrum was recorded utilizing a 385 nm excitation source. Observing the PL spectra, all samples (A, B, and C) exhibit a pronounced emission band at 484 nm, accompanied by weaker emission bands at 428 nm, 525 nm, and 632 nm. These bands are associated with different charge states of oxygen vacancies, such as Vo⁰, Vo⁺, and Vo⁺⁺. Photo-excitation of SnO\u003csub\u003e2\u003c/sub\u003e may result in the trapping of holes at the Vo⁺ centre, leading to the formation of Vo⁺⁺ centres, as indicated by the emission peak around 400 nm [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e, \u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. The emission at 428 nm is attributed to residual stresses within the tin dioxide nanocrystals, originating from lattice distortion [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. The prominent emission peak at 484 nm is linked to blue luminescence in SnO\u003csub\u003e2\u003c/sub\u003e, primarily caused by oxygen-related defects introduced during the growth process [\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. The peaks at 525 nm and 632 nm are associated with V\u003csub\u003eO\u003c/sub\u003e⁺ oxygen vacancies [\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]. Remarkably, despite exposure to microwave radiation, all three samples emit similar radiations, suggesting that the mechanism driving the blue emission is primarily influenced by the concentration of free electrons and the presence of various identified point defects, including Vo.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.2 Thermal characterization\u003c/h2\u003e \u003cp\u003eThermogravimetric analysis (TGA) of microwave-synthesized tin oxide was conducted to assess weight loss under N\u003csub\u003e2\u003c/sub\u003e atmosphere, as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e11\u003c/span\u003e. The observed weight loss profile provides insights into various processes occurring within the sample. Between 30\u0026deg;C and 250\u0026deg;C, a weight loss of approximately 1.249% is noted. This initial loss is attributed to the elimination of ammonia, physically absorbed water, and chemically bonded water, manifested by an endothermic peak [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Subsequently, from 250\u0026deg;C to 600\u0026deg;C, a weight loss of 6.360% occurs, corresponding to desorption and decomposition of the surfactant template. The final weight loss, around 4.895% between 600\u0026deg;C and 860\u0026deg;C, is linked to dihydroxylation on the surface and the removal of residual surfactant [\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e]. The Differential Thermal Analysis (DTA) results align with the TGA findings, revealing broad peaks from 250\u0026deg;C to 600\u0026deg;C and 600\u0026deg;C to 860\u0026deg;C, indicative of residual surfactant presence in these temperature ranges. The combined TGA and DTA analyses offer a comprehensive understanding of the thermal behaviour and decomposition processes involved in the microwave-synthesized tin oxide.\u003c/p\u003e \u003cp\u003eThe current study presents an exploration of the optical properties of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures under the influence of microwave radiation. The optical characteristics of SnO\u003csub\u003e2\u003c/sub\u003e, such as its band gap (e.g., 3.6 eV for bulk materials), have traditionally been obtained through various techniques that often require prolonged exposure times and substantial energy consumption, particularly due to the necessity for high-temperature treatment. In contrast, our approach involves the rapid synthesis of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures within a remarkably short timeframe of 5\u0026ndash;15 minutes using microwave radiation, and notably, without the addition of any surfactants or chemical agents. Microwave heating facilitates instant volumetric heating, resulting in a significantly accelerated process compared to conventional heating methods. This accelerated sintering kinetics, enabled by microwave radiation, allows for a reduction in both temperature and processing time, thereby increasing productivity and minimizing energy consumption [\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. This innovative method not only offers efficiency in synthesis but also underscores the potential for sustainable and energy-conscious fabrication of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eThe synthesis of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures was successfully achieved through a microwave-assisted technique, enabling a comprehensive investigation of their structural, optical, and thermal properties. The XRD pattern confirmed a Cassiterite-type tetragonal structure, with a crystallite size of 19\u0026ndash;24 nm, as determined by both XRD and TEM analyses. The EDX spectrum affirmed the formation of pure SnO\u003csub\u003e2\u003c/sub\u003e without any impurities. The optical properties, including direct and indirect band gaps (3.86 and 1.56 eV, respectively), and various optical constants (refractive index, absorbance, extinction coefficient, real and imaginary parts of the dielectric constant, and optical conductivity), were determined through UV-DRS. Photoluminescence analysis revealed a strong blue emission peak at 484 nm. Thermal analysis via TGA/DTA provided insights into the material's thermal behaviour. Importantly, microwave radiation at different time intervals demonstrated no adverse effects on the optical properties. This method allows for the rapid synthesis of SnO\u003csub\u003e2\u003c/sub\u003e nanostructures within a short duration, reducing energy consumption, enhancing crystal quality, and yielding fine optical properties. The approach was found to be a convenient, mild, and efficient route for the controlled synthesis of tin oxide nanostructures. Proposing this synthesis method for optoelectronic applications underscores its potential for practical use in various technological domains.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAcknowledgments:\u003c/p\u003e\n\u003cp\u003eI would like to express my deepest gratitude to my family for their unwavering support and encouragement. To my parents, for their endless love and guidance. To my brother, for always being there for me. To my wife, for her patience, understanding, and support. To my daughter, for her joy and inspiration. Your constant encouragement, motivation and support has been invaluable throughout this journey.\u003c/p\u003e\n\u003cp\u003eAuthor contributions:\u003c/p\u003e\n\u003cp\u003eAuthor 1: Dr.N.RAJESH (Corresponding author)\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eConceived and designed the analysis\u003c/li\u003e\n\u003cli\u003eCollection of data\u003c/li\u003e\n\u003cli\u003eContributed data analysis\u003c/li\u003e\n\u003cli\u003eWrote the paper\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAuthor 2: P.NAGARANI SOBANA (Co-author)\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eData interpretation\u003c/li\u003e\n\u003cli\u003eSystem work\u003c/li\u003e\n\u003cli\u003ePlotting graph\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eConflicts of interest or competing interests:\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003eData and code availability:\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003eSupplementary information:\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e\n\u003cp\u003eEthical approval:\u003c/p\u003e\n\u003cp\u003eNot Applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAmeer Azam, Arham S. Ahmed, Sami S. Habib, A.H. Naqvi (2012) Effect of Mn doping on the structural and optical properties of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles. J Alloys Compd 523:83\u0026ndash; 87. https://doi.org/10.1016/j.jallcom.2012.01.072.\u003c/li\u003e\n\u003cli\u003eS.D.Monredon, A. Cellot, F. Ribot, C. Sanchez, L.D. Armelao, L.Guanean, L. Delattre (2002) Synthesis and characterization of crystalline tin oxide nanoparticles. J Mater Chem 12:2396 - 2400. https://doi.org/10.1039/B203049G\u003c/li\u003e\n\u003cli\u003eK.L.Chopra, S.Major, D.K.Pandya (1983) Transparent conductors\u0026mdash;A status review. Thin Solid Films. 102: 1-46. https://doi.org/10.1016/0040-6090(83)90256-0\u003c/li\u003e\n\u003cli\u003eK.Sekizawa, H.Widjaja, S.Maeda, Y.Ozawa, K.Egnehi (2000) Low temperature oxidation of methane over Pd/SnO\u003csub\u003e2\u003c/sub\u003e catalyst, Appl Catal A 200:211-217. https://doi.org/10.1016/S0926-860X(00)00634-7\u003c/li\u003e\n\u003cli\u003eN.Sergent, P.Gelin, L.P.Camby, H.Praliaud, G.Thomas (2002) Preparation and characterisation of high surface area stannic oxides: structural, textural and semiconducting properties, Sensors Actuators B: Chem 84:176-188. https://doi.org/10.1016/S0925-4005(02)00022-9\u003c/li\u003e\n\u003cli\u003eZ.L.Wang (2003) Nanobelts, Nanowires, and Nanodiskettes of Semiconducting Oxides\u0026mdash;From Materials to Nanodevices, Adv Mater 15:432-436. https://doi.org/10.1002/adma.200390100\u003c/li\u003e\n\u003cli\u003eY.Zhang, A.Kolmakov, S.Chretien, H.Metiu, M.Moskovits (2004) Control of Catalytic Reactions at the Surface of a Metal Oxide Nanowire by Manipulating Electron Density Inside It, Nano Lett 4:403-407. https://doi.org/10.1021/nl034968f\u003c/li\u003e\n\u003cli\u003eT.T.Emons, J.Li, L.F.Nazar (2002) Synthesis and Characterization of Mesoporous Indium Tin Oxide Possessing an Electronically Conductive Framework, J Am Chem Soc 124:8516-8517. https://doi.org/10.1021/ja0125826\u003c/li\u003e\n\u003cli\u003eS.Ferrere, A. Zaban, B.A.Gregg (1997) Dye Sensitization of Nanocrystalline Tin Oxide by Perylene Derivatives, J Phys Chem B 101:4490-4493. https://doi.org/10.1021/jp970683d \u003c/li\u003e\n\u003cli\u003eF.Gu, S.F.Wang, M.K.Lu, Y.X.Qi, G.J.Zhou, D.Xu, D.R.Yuan (2004) Luminescent characteristics of Eu\u003csup\u003e3+\u003c/sup\u003e in SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles, Opt Mater 25:59-64 https://doi.org/10.1016/S0925-3467(03)00226-X \u003c/li\u003e\n\u003cli\u003eT. Hayakawa, M. Nogami (2005) High luminescence quantum efficiency of Eu\u003csup\u003e3+-\u003c/sup\u003edoped SnO\u003csub\u003e2\u003c/sub\u003e\u0026ndash;SiO\u003csub\u003e2\u003c/sub\u003e glasses due to excitation energy transfer from nano-sized SnO\u003csub\u003e2\u003c/sub\u003e crystals, Sci Technol Adv Mater 6:66-70. 10.1016/j.stam.2004.08.003.\u003c/li\u003e\n\u003cli\u003eM. Ruske, G. Brauer, J. Pistner, U. Pfafflin, J. Szczyrbowski (1999) Properties of SnO\u003csub\u003e2\u003c/sub\u003e film prepared by DC and MF reactive sputtering, Thin Solid Films 351:146\u0026ndash;150. https://doi.org/10.1016/S0040-6090(99)00083-8\u003c/li\u003e\n\u003cli\u003eY. Ning, W. Jianhua, G. Yuzhong, Z. Xiaolong (2008) SnO\u003csub\u003e2\u003c/sub\u003e nanofibers prepared by sol\u0026ndash;gel template method, Rare Met Mater Eng 37:694\u0026ndash;696. https://doi.org/10.1016/S1875-5372(09)60019-9\u003c/li\u003e\n\u003cli\u003eJ. Ahmed, S. Vaidya, T. Ahmad, P.S. Devi, D. Das, A. K. Ganguli (2008) Tin dioxide nanoparticles: reverse micellar synthesis and gas sensing properties, Mater Res Bull 43:264\u0026ndash;271. https://doi.org/10.1016/j.materresbull.2007.03.013\u003c/li\u003e\n\u003cli\u003eS.H. Luo, Q. Wan, W.L. Liu, M. Zhang, Z.T. Song, C.L. Lin, Paul K. Chu (2005) Photoluminescence properties of SnO\u003csub\u003e2\u003c/sub\u003e nanowhiskers grown by thermal evaporation, Prog Solid State Chem 33:287\u0026ndash;292. https://doi.org/10.1016/j.progsolidstchem.2005.11.008\u003c/li\u003e\n\u003cli\u003eJ. Pal, P. Chauhan, Structural and optical characterization of tin dioxide nanoparticles prepared by a surfactant mediated method (2009) Mater Charact 60:1512\u0026ndash;1516. 10.1016/j.matchar.2009.08.007\u003c/li\u003e\n\u003cli\u003eAdamo Fini, Alberto Breccia, Chemistry by microwaves, Pure Appl Chem 71 (1999) 573\u0026ndash;579. http://dx.doi.org/10.1351/pac199971040573\u003c/li\u003e\n\u003cli\u003eFeng Gu, Shu Fen Wang, Meng Kai Lu, Xiu Feng Cheng, Su Wen Liu, Guang Jun Zhou, Dong Xu, Duo Rong Yuan (2004) Luminescence of SnO\u003csub\u003e2\u003c/sub\u003e thin films prepared by spin-coating method, J Cryst Growth 262: 182\u0026ndash;185. 10.1016/j.jcrysgro.2003.10.028\u003c/li\u003e\n\u003cli\u003eA.Y. El-Etre, S.M. Reda (2010) Characterization of nanocrystalline SnO\u003csub\u003e2\u003c/sub\u003e thin film fabricated by electro deposition method for dye-sensitized solar cell application, Appl Surf Sci 256:6601\u0026ndash;6606. https://doi.org/10.1016/j.apsusc.2010.04.055\u003c/li\u003e\n\u003cli\u003eM. Parthibavarman, V. Hariharan, C. Sekar , V. N. Singh, Effect of copper on structural, optical and electrochemical properties of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles (2010) J Optoelectron Adv M 12:1894 \u0026ndash; 1898. https://joam.inoe.ro/articles/effect-of-copper-on-structural-optical-and-electrochemical-properties-of-sno\u003csub\u003e2\u003c/sub\u003e-nanoparticles/fulltext\u003c/li\u003e\n\u003cli\u003eG.E. Patil, D. D. Kajale, V. B. Gaikwad, G. H. Jain, Preparation and characterization of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles by hydrothermal route (2012) Int Nano Lett 17:1-5. https://doi.org/10.1186/2228-5326-2-17\u003c/li\u003e\n\u003cli\u003eA. Cirera, A. Vila, A. Cornet, J.R. Morante (2001) Properties of nanocrystalline SnO\u003csub\u003e2\u003c/sub\u003e obtained by means of a microwave process, Mater Sci Eng C 15:203-205. https://doi.org/10.1016/S0928-4931(01)00243-0\u003c/li\u003e\n\u003cli\u003eW.D. Callister, Materials science and engineering-an introduction, Wiley, New York, 1997.\u003c/li\u003e\n\u003cli\u003eD.P. Padiyan, A. Marikini, K.R.Murli (2004) Effect of thickness on the properties of vacuum deposited Cd\u003csub\u003e0.75\u003c/sub\u003eSn\u003csub\u003e0.25\u003c/sub\u003e Se mixed chalcogenide thin films, Mat Chem Phys 88:250-257. https://doi.org/10.1016/j.matchemphys.2003.09.050\u003c/li\u003e\n\u003cli\u003eK.R. Murali, A. Kalaivanan, S. Perumal, N. Neelakanda Pillai (2010) Sol\u0026ndash;gel dip coated CdO:Al films, J. Alloys Compd, 503:350 \u0026ndash; 353. https://doi.org/10.1016/j.jallcom.2009.11.187\u003c/li\u003e\n\u003cli\u003eH. Zhu, D. Yang, G. Yu, H. Zhang K. Yao, A simple hydrothermal route for synthesizing SnO\u003csub\u003e2\u003c/sub\u003e quantum dots (2006) Nanotechnol, 17:2386 \u0026ndash; 2389. 10.1088/0957-4484/17/9/052\u003c/li\u003e\n\u003cli\u003eHongmei Deng and Jeanne M. Hossenlopp, Combined X-ray Diffraction and Diffuse Reflectance Analysis of Nanocrystalline Mixed Sn(II) and Sn(IV) Oxide Powders (2005) J Phys Chem B 109:66-73. 10.1021/jp047812s\u003c/li\u003e\n\u003cli\u003eC.M. Liu, X.T. Zu, Q.M. Wei, L.M. Wang, Fabrication and characterization of wire-like SnO\u003csub\u003e2 \u003c/sub\u003e(2006) J. Phys D Appl Phys 39:2494-2497. 10.1088/0022-3727/39/12/004\u003c/li\u003e\n\u003cli\u003eGanesh E Patil, Dnyaneshwar D Kajale, Vishwas B Gaikwad, Gotan H Jain (2012) Preparation and characterization of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles by hydrothermal route, Int. Nano Lett, 17:1\u0026ndash;5 https://doi.org/10.1186/2228-5326-2-17\u003c/li\u003e\n\u003cli\u003eArham S.Ahmed, M. Shafeeq Muhamed, M. L. Singla, Sartaj Tabassum, Alim H. Naqvi, Ameer Azam (2011) Band gap narrowing and fluorescence properties of nickel doped SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles Journal of Luminescence 131:1\u0026ndash;6. https://doi.org/10.1016/j.jlumin.2010.07.017\u003c/li\u003e\n\u003cli\u003eHongmei Deng, Jeanne M. Hossenlopp, Combined X-ray Diffraction and Diffuse Reflectance Analysis of Nanocrystalline Mixed Sn(II) and Sn(IV) Oxide Powders (2005) J Phys Chem B 109:66-73. 10.1021/jp047812s\u003c/li\u003e\n\u003cli\u003eM. Parthibavarman, V. Hariharan, C. Sekar, High-sensitivity humidity sensor based on SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles synthesized by microwave irradiation method (2011) Mater Sci Eng C 31:840\u0026ndash;844. https://doi.org/10.1016/j.msec.2011.01.002 \u003c/li\u003e\n\u003cli\u003eL.M. Fang, X.T. Zu, Z.J. Li, S. Zhu, C.M. Liu, L.M. Wang, F. Gao, Microstructure and luminescence properties of Co-doped SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles synthesized by hydrothermal method (2008) J Mater Sci Mater Electron 19:868 \u0026ndash; 874. 10.1007/s10854-007-9543-7\u003c/li\u003e\n\u003cli\u003eT. Takagahara, K. Takeda (1992) Theory of the quantum confinement effect on excitons in quantum dots of indirect-gap materials, Phys Rev B 46:15578 - 15581. https://doi.org/10.1103/PhysRevB.46.15578\u003c/li\u003e\n\u003cli\u003eC. Aydın, Omar A, Al-Hartomy, A. A. Al-Ghamdi, F. Al-Hazmi, I. S. Yahia, F. El-Tantawy, F. Yakuphanoglu (2012) Controlling of crystal size and optical band gap of CdO nanopowder semiconductors by low and high Fe contents, J Electroceram 29:155\u0026ndash;162. 10.1007/s10832-012-9748-x\u003c/li\u003e\n\u003cli\u003eSalih Kose, Ferhunde Atay, Vildan Bilgin, Idris Akyuz (2009) In doped CdO films: Electrical, optical, structural and surface properties, Int J Hydrogen Energy 34:5260 \u0026ndash; 5266. 10.1016/j.ijhydene.2008.11.110\u003c/li\u003e\n\u003cli\u003eA.K. Wolaton, T.S. Moss (1963) Determination of Refractive Index and Correction to Effective Electron Mass in PbTe and PbSe, Proc R Soc 81:509-513.\u003c/li\u003e\n\u003cli\u003eMujdat Caglar, Saliha Ilican, Yasemin Caglar, Fahrettin Yakuphanoglu (2009) Electrical conductivity and optical properties of ZnO nanostructured thin film, App Surf Sci 255:4491\u0026ndash;4496. https://doi.org/10.1016/j.apsusc.2008.11.055\u003c/li\u003e\n\u003cli\u003eJ.N. Hodgson (1970) Optical Absorption and Dispersion in Solids, Chapman and Hall LTD, 11 New fetter Lane London EC4.\u003c/li\u003e\n\u003cli\u003eFahrettin Yakuphanoglu, Saliha Ilican, Mujdat Caglar, Yasemin Caglar (2010) Microstructure and electro-optical properties of sol gel derived Cd-doped ZnO films, Superlattices. Microstruct, 47:732-743. https://doi.org/10.1016/j.spmi.2010.02.006\u003c/li\u003e\n\u003cli\u003eM.A. Gondal, Q.A. Drmosh, T.A. Saleh (2010) Preparation and characterization of SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles using high power pulsed laser, App Surf Sci 256:7067\u0026ndash;7070. 10.1016/j.apsusc.2010.05.027\u003c/li\u003e\n\u003cli\u003eF. Gu, S.F. Wang, M.K. Lu, X.F. Cheng, S.F. Liu, G.J. Zhou, X. Dong, D.R. Yuan (2004) Luminescence of SnO\u003csub\u003e2\u003c/sub\u003e thin films prepared by spin-coating method, J Cryst Growth 262:182\u0026ndash;185. https://doi.org/10.1016/j.jcrysgro.2003.10.028\u003c/li\u003e\n\u003cli\u003eY. Her, J. Wu, Y.R. Lin, S.Y. Tsai (2006) Low-temperature growth and blue luminescence of SnO\u003csub\u003e2\u003c/sub\u003e nanoblades, Appl Phys Lett 89:043115-043123. 10.1063/1.2235925\u003c/li\u003e\n\u003cli\u003eJ.X. Zhou, M.S. Zhang, J.M. Hong, Z. Yin (2006) Raman spectroscopic and photoluminescence study of single-crystalline SnO\u003csub\u003e2\u003c/sub\u003e nanowires, Solid State Commun, 138 :242\u0026ndash;246. https://doi.org/10.1016/j.ssc.2006.03.007\u003c/li\u003e\n\u003cli\u003eYude Wang, chunlai Ma, Xiaodan Sun, Hengde Li (2001) Synthesis of mesoporous structured material based on tin oxide, Micropor. Mesopor. Mat. 49:171-178. 10.1016/S1387-1811(01)00415-2\u003c/li\u003e\n\u003cli\u003eAvijit Mondal, Dinesh Agrawa, Anish Upadhyaya (2009) Microwave Heating of Pure Copper Powder with Varying Particle Size and Porosity, J Microw Power Electromagn Energy 43:5-10. 10.1080/08327823.2008.11688599.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table 1","content":"\u003cp\u003eTable.1 Values of crystallite size D, strain \u0026epsilon; and the dislocation density \u0026delta; of microwave assisted tin oxide\u003c/p\u003e\n\u003cp\u003enanostructures samples\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"575\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.11111111111111%\" rowspan=\"2\"\u003e\n \u003cp\u003eSample\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.40277777777778%\" rowspan=\"2\"\u003e\n \u003cp\u003eMicrowave irradiation (min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.756944444444445%\" rowspan=\"2\"\u003e\n \u003cp\u003eThe average crystallite size (nm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.65972222222222%\" rowspan=\"2\"\u003e\n \u003cp\u003eThe dislocation density \u0026delta;\u0026times;10\u003csup\u003e15\u003c/sup\u003e (lines/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"35.06944444444444%\" colspan=\"3\"\u003e\n \u003cp\u003eThe strain \u0026epsilon; \u0026times; 10\u003csup\u003e\u0026minus;3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"32.67326732673267%\"\u003e\n \u003cp\u003e(110)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"32.67326732673267%\"\u003e\n \u003cp\u003e(101)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"34.65346534653465%\"\u003e\n \u003cp\u003e(211)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"11.11111111111111%\" rowspan=\"3\"\u003e\n \u003cp\u003eSnO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"18.40277777777778%\" valign=\"bottom\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.756944444444445%\" valign=\"bottom\"\u003e\n \u003cp\u003e24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.65972222222222%\" valign=\"bottom\"\u003e\n \u003cp\u003e1.7361\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.458333333333334%\" valign=\"bottom\"\u003e\n \u003cp\u003e77.8567\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"11.458333333333334%\" valign=\"bottom\"\u003e\n \u003cp\u003e119.5826\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.152777777777779%\" valign=\"bottom\"\u003e\n \u003cp\u003e224.9465\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.703125%\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.6015625%\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.2421875%\"\u003e\n \u003cp\u003e2.2675\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.890625%\"\u003e\n \u003cp\u003e87.5879\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.890625%\"\u003e\n \u003cp\u003e90.8890\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.671875%\"\u003e\n \u003cp\u003e76.4766\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.703125%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.6015625%\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.2421875%\"\u003e\n \u003cp\u003e2.77\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.890625%\"\u003e\n \u003cp\u003e80.2860\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"12.890625%\"\u003e\n \u003cp\u003e93.2729\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.671875%\"\u003e\n \u003cp\u003e98.9672\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"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":"journal-of-nanoparticle-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nano","sideBox":"Learn more about [Journal of Nanoparticle Research](http://link.springer.com/journal/11051)","snPcode":"11051","submissionUrl":"https://submission.nature.com/new-submission/11051/3","title":"Journal of Nanoparticle Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Tin oxide, chemical synthesis, Microwave technique, nanostructures, optical property","lastPublishedDoi":"10.21203/rs.3.rs-4580952/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4580952/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eSemiconducting tin oxide (SnO\u003csub\u003e2\u003c/sub\u003e) nanostructures were successfully synthesized using a simple, rapid, and energy-saving microwave-assisted technique. The prepared SnO\u003csub\u003e2\u003c/sub\u003e samples were characterized by XRD, TEM, EDX, UV\u0026ndash;DRS, photoluminescence, and TGA/DTA, demonstrating good crystal quality. The structure and surface morphology of the samples were investigated as a function of microwave irradiation using X-ray diffraction (XRD) and Transmission Electron Microscope (TEM). Structural studies by XRD revealed that the samples exhibit a tetragonal cassiterite structure, with a crystallite size observed to vary from 2 to 23 nm according to TEM measurements. UV-VIS diffuse reflectance spectroscopy (DRS) indicated that the direct and indirect band gap energies of SnO\u003csub\u003e2\u003c/sub\u003e are 3.86 and 1.56 eV, respectively. To highlight the optical properties of the SnO\u003csub\u003e2\u003c/sub\u003e nanostructures, the variation of photon energy concerning microwave radiation was investigated through absorption and extinction coefficient studies, refractive index, dielectric constant, and optical conductivity studies. The SnO\u003csub\u003e2\u003c/sub\u003e nanoparticles exhibited emission peaks at 428, 484, 525, and 632 nm in the photoluminescence spectrum. The major weight loss observed in thermo gravimetric analysis and differential thermal analysis (TGA/DTA) corresponds to the formation of tin oxide.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e","manuscriptTitle":"Microwave-Assisted Synthesis and Evaluation of SnO 2 Nanostructures: Structural, Optical, and Thermal Characterization","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-07-16 15:58:43","doi":"10.21203/rs.3.rs-4580952/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorAssigned","content":"","date":"2024-06-18T20:06:57+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-06-18T13:00:18+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Nanoparticle Research","date":"2024-06-14T09:19:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-nanoparticle-research","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"nano","sideBox":"Learn more about [Journal of Nanoparticle Research](http://link.springer.com/journal/11051)","snPcode":"11051","submissionUrl":"https://submission.nature.com/new-submission/11051/3","title":"Journal of Nanoparticle Research","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"7d67272f-d0da-4583-97c6-8fdce449eaae","owner":[],"postedDate":"July 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2024-07-16T15:58:43+00:00","versionOfRecord":[],"versionCreatedAt":"2024-07-16 15:58:43","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4580952","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4580952","identity":"rs-4580952","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}