Preparation of Visible-Light Responsive Photocatalyst SxTi1-XO2
Sulfur-doped titanium dioxide powders (SxTi1-xO2) was prepared by calcinations, that is, the hydrolysis of acidic tetra-butyl tianate using thiourea in ethanol, followed by calcinations at temperatures about 500°C. Based on the characterizations of XRD, BET, surface photovoltage spectroscopy (SPS), electric-field-induced surface photovoltage spectroscopy (EFISPS) and XPS, it was found that the sulfur could restrain the crystallization transformation of TiO2 from anatase to rutile, although the calcinations temperature has attained 500°C, the crystallization still were anatase entirely. The catalysts exhibited photocatalytic activity in the visible light region owing to S-doping. The light absorption onset of SxTi1-xO2 was shifted to the visible region at 550nm compared to 329nm of pure TiO2. In the crystal, the S atoms occupied some of the lattice titanium atoms for form S-O bonds. Photocatalytic decomposition of benzoic acid solutions was carried out under simulated sun light, and the SxTi1-xO2 catalyst showed higher activity than pure TiO2.
Y. Q. Wang et al., "Preparation of Visible-Light Responsive Photocatalyst SxTi1-XO2", Materials Science Forum, Vol. 694, pp. 602-607, 2011