Influence of Calcination Temperature on the Structure and Porosity of Nanocrystalline SnO2 Synthesized by a Conventional Precipitation method

Tin dioxide nanocrystalline were synthesized by adding ammonia solution (NH4 OH) to a solution containing tin chloride pentahydrate (SnCl4.5H2O). The obtained products have been characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). The results indicate that the crystallite size increases from 3.45 to 23.5 nm as the calcination temperature rises from 300oC to 1050oC. The XRD analysis exhibits a rutile tetragonal phase of the SnO2 nanocrystals. The crystallinity is developed due to a decrease of lattice distortion ratio and dislocation density as the calcination temperature is increases. Surface area and porosity of SnO2 nanoparticles are measured. Specific surface area which is related to pore volume and decreases from 140 m /g at 100°C to 8.3 m2/g at 1050°C.