Synthesis and characterization of bismuth-doped tin dioxide nanometer powders

Bismuth-doped tin dioxide nanometer powders were prepared by co-precipitation method using SnCl4 and Bi(NO3)3 as raw materials. The effects of calcining temperature and doping ratio on the particle size, composition, spectrum selectivity of bismuth-doped tin dioxide and the phase transition of Bi-Sn precursor at different temperatures were studied by means of X-ray diffraction, transmission electron microscopy, ultraviolet-visual-near infrared diffuse reflection spectrum and the thermogravimetric-differential scanning calorimetry. The results show that prepared bismuth-doped tin dioxide powders have excellent characteristics with a single-phase tetragonal structure, good dispersibility, good absorbency for ultraviolet ray and average particle size less than 10 nm. The optimum conditions for preparing bismuth-doped tin dioxide nanometer powders are as follows: calcining temperature of 600 °C, ratio of bismuth-doped in a range of 0.10–0.30, and Bi-Sn precursor being dispersed by ultrasonic wave and refluxed azeotropic and distillated with mixture of n-butanol and benzene. The mechanism of phase transition of Bi-Sn precursor is that Bi3+ enters Sn-vacancy and then forms Sn-O-Bi bond.