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The present study reported the temperature dependent properties of tin oxide (SnO2) thin films deposited by using conventional, cost effective and non-vacuum-based spray pyrolysis technique (SPT). The as deposited films were characterized by various characterization techniques such as X ray diffraction (XRD), UV-Vis spectroscopy and Scanning electron microscopy (SEM) to study their structural, optical and morphological properties respectively. XRD analysis revealed tetragonal rutile crystal structure of SnO2 with preferred orientation along (200) plane. The refinement of XRD data was also carried out by Rietveld refinement to obtain the fitting parameters, crystallite size and lattice parameters. UV-Vis study showed considerable change in optical absorbance and transmittance with change in substrate temperature. Effect of substrate temperature on film thickness, refractive index and band gap energy were determined by Swanepoel method and by Tauc’s plot respectively. The Urbach energy was also calculated and were correlated to the defects in SnO2 films. SEM micrograph showed the transformation from granules to nanospheres as a function of substrate temperature. Electrical properties were determined by Hall effect measurements which gives carrier concentration, electrical resistivity and mobility in the order of 1019-1020 /cm3, 10−2-10−3 Ω.cm and 4–23 cm2/Vs respectively.

In this study, zinc oxide (ZnO) and zinc oxide-zirconium dioxide nanocomposites (ZnO@ZrO2) were synthesized by a low-cost solution combustion route to study their structural, morphological, optical, and photocatalytic performance. The properties of synthesized nanocomposites were characterized by x-ray diffraction (XRD), UV–vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). Phase formation and purity were confirmed using XRD and EDS. Optical absorption spectra revealed that the addition of ZrO2 significantly affected optical absorption and band gap energy. The band gap energy increased from 3.01 to 3.24 eV with addition of ZrO2 in ZnO. FTIR spectra confirmed the formation of ZnO and ZnO@ZrO2. SEM micrographs showed a significant change in the morphology of the ZrO2 addition in ZnO. BET analysis showed surface area for sample P3 (ZnO@0.4ZrO2) was 28.9 m2/g while for sample P1 (ZnO) was 22.5 m2/g. In addition, the photocatalytic performance of ZnO and ZnO@ZrO2 for the decomposition of methylene blue (MB) dye was studied for all samples exposed to solar light. The effect of different contents of ZrO2 in ZnO@ZrO2 in terms of degradation efficiency and degradation time are described in detail. The sample P3 showed highest photodegradation efficiency of 84.52 % at degradation time of 240 minutes.