Pyrolysis of organotin compounds: A preparative method for nanometric tin dioxide powders

Abstract

Nanometric tin dioxide powders were obtained by pyrolysis of organotin oxide based compounds such as Sn₃O₃Bu₆ (1) and Sn₄O₆Bu₄ (2) (Bu = n-butyl). The thermal behaviour of 1 and 2 was studied by thermogravimetric analysis (TG) and with simultaneous differential thermal analysis (DTA). Pyrolysis experiments were carried out in three different atmospheres (N₂, air and O₂) and the residual powders were characterised by X-ray diffraction (XRD) and the morphology was investigated by scanning electron microscopy (SEM). The XRD data showed the formation of pure SnO₂ when the decomposition process was accomplished in air or O₂, however, in N₂, and for Sn₄O₆Bu₄, the X-ray study indicated the formation of a mixture of SnO/SnO₂. The micrographs revealed grains of 30–40 nm, approximately.