Low temperature synthesis of SnO2 nanocrystals from tin, sulfur and ammonium chloride powders

Tetragonal phase SnO₂ nanocrystals were synthesized directly by heating the mixture of tin (Sn), sulfur (S) and ammonium chloride (NH₄Cl) powders in air at 400 °C for 2-5 h. The phase, size and purity of the resultant products were characterized by means of powder X-ray diffraction (XRD), filed emission scanning electronic microscope (FESEM), and energy dispersive X-ray (EDX) spectra. Besides, the effects of heating temperature, duration, and composition of the reactants on the phases of the resultant products were investigated. It was found that both of the S and NH₄Cl additives played important roles in the current low temperature (400 °C) synthesis of pure SnO₂.