WO3−x horizontally-grown on TiO2(B) nanosheets for enhanced photo- and electro-chemical activity

Abstract

WO3−x was deposited on TiO2(B) nanosheets prepared using TiCl4 to form layered heterostructures via a two-step solvothermal synthesis, in which the horizontal growth of WO3−x on TiO2(B) nanosheets was carried out using WCl6 and ascorbic acid as a reducer. Optimized preparation conditions allowed WO3−x/TiO2(B) layered heterostructures to be formed. The photo- and electro-chemical properties of layered heterostructures depended strongly on the amount of WO3−x. The WO3−x/TiO2(B) heterostructures demonstrated perfect catalytic performance in full solar-spectrum light and a fast degradation effect for dye and organic colorless pollutant. All target chemicals were degraded within 10 min using WO3−x/TiO2(B) samples as a photo-catalyst in the full solar-spectrum. The photo-assisted production kinetic of Cr(VI) ions were tested. The results indicate that the reproduction rate of Cr(VI) ions using WO3−x/TiO2(B) sample is three times higher than the initial TiO2 nanosheets. The result of the photo current and Mott–Shottky curve indicates that enhanced catalysis activity is ascribed to the surface of the metastable TiO2(B) with Ti3+ defects and oxygen vacancies as active sites for photocatalytic reaction. In addition, the loading of WO3−x greatly broadened the light absorption range of TiO2(B), meaning that the product responded in the full solar spectrum.