Thermally induced structural changes and optical properties of tin dioxide nanoparticles synthesized by a conventional precipitation method

Tin dioxide (SnO2) nanoparticles were synthesized by a conventional precipitation method using the reaction between tin chloride pentahydrate and ammonia solutions. The obtained powders were calcined at varied temperatures from 300 to 1050 degrees C, and then characterized by using thermogravimetric analysis, differential thermal analysis and Fourier transformation infrared spectroscopy. The average crystallite size, determined by x-ray diffraction, was found to be in the range of 3.45-23.5 nm. The analysis exhibited a tetragonal phase. The activation energy of crystal growth was calculated and found to be 12.12 kJ/mol. The microstructure of nanoparticles was examined by high resolution transmission electron microscopy. Optical properties were investigated by a UV-vis absorption spectrophotometer. The calculated optical band gap lies between 4.75-4.25 eV as a result of increasing the calcination temperatures and crystallite size. (C) 2013 Published by Elsevier Ltd.