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

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 (N-2, air and O-2) 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 O-2, however, in N-2, 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.