Preparation of nanosized tin oxide (SnO2) powder by homogeneous precipitation

Synthesis of nanosized SnO2 ceramic particles via homogeneous precipitation was investigated as a function of processing parameters such as initial concentration and calcination temperature. Hydrous tin oxide was precipitated from 0.01 to 1 M SnCl4-urea aqueous solutions by decomposition of urea at ∼90 °C. Initial concentration has a significant effect on phase formation and crystallite size of the prepared powder. The crystallite size of tin dioxide increased with increasing initial concentration. For example, while crystallite size was 11.7 nm for 0.033 M SnCl4 system, it was 25.3 nm for 0.25 M SnCl4 system. In addition, tin dioxide particles as small as a few nanometers were obtained by homogeneous precipitation. However, calcination resulted in crystal growth and agglomeration and subsequently, reduction in the effective surface area of tin dioxide powders.