Abstract
Semiconducting tin oxide (SnO2) nanostructures were successfully synthesized using a simple, rapid, and energy-saving microwave-assisted technique. The prepared SnO2 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 SnO2 are 3.86 and 1.56 eV, respectively. To highlight the optical properties of the SnO2 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 SnO2 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.