The influence of phosphate on crystal grain growth of nanosized SnO2

The nanosized SnO2 particles were prepared by chemical precipitation method using ammonium hydroxide and tin tetrachloride. The obtained SnO2 powders were treated by soaking in the phosphate solution with different concentrations for 24 h. The as-prepared powders and the samples treated with phosphate were calcined at different high temperatures. The powders were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron micrographs (TEM) and X-ray photoelectronic spectroscopy (XPS). The experiment results show that the untreated SnO2 particles grow to bulk material with the annealing temperature increasing while the crystal size of SnO2 modified by phosphate rose slowly under the same condition. This phenomenon implied that phosphate treatment played an important role in inhibiting the crystal grain growth of SnO2 calcined at high temperature. The possible mechanism for the inhibition effect of phosphate on tin dioxide was discussed.