Synthesis of nanocrystalline SnO2 powder from SnCl4 by mechanochemical processing

The rapid synthesis of nanocrystalline SnO2 powder using a mechanochemical reaction of SnCl4 (instead of the widely used tin (II) compounds) with (NH4)2CO3 and the subsequent annealing of the product in air and under an H2O/NH3 atmosphere has been investigated using X-ray powder diffraction, TG and TEM. The reaction was complete within 5 min. Additional milling of the product at a higher milling intensity for 120 min led to the crystallisation of tetragonal SnO2. The NH4Cl salt matrix was removed by annealing at 300 °C. The average crystallite size of tetragonal SnO2 was in the range of 2–48 nm and it can be controlled by variation heating temperatures and annealing atmospheres in the range of 300–700 °C.