Preparation, characterization and photo-catalytic behavior of WO3-TiO2 catalysts with oxygen vacancies
(1. Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation,
Chemical and Biologic Engineering Institute, Changsha Science and Technology University, Changsha 410076, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
Chemical and Biologic Engineering Institute, Changsha Science and Technology University, Changsha 410076, China;
2. School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China)
Abstract: TiO2 photocatalysts compounded with WO3 were prepared via a modified hydrolysis process and the 2% WO3-TiO2 catalysts with different oxygen vacancies were obtained by calcination at 873 K in H2 atmosphere. The catalysts were identified using X-ray diffractometry (XRD), specific surface measurement (BET), electron paramagnetic resonance spectroscopy (EPR), UV-Vis diffusion refraction spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of 2% WO3-TiO2 with different oxygen vacancies was investigated employing splitting of water for O2 evolution. The results indicate that appropriate oxygen vacancies can obviously improve the photocatalytic activity of 2% WO3-TiO2 catalysts, and using Fe3+ as an electron acceptor under UV irradiation in 12 h, the maximum rate for O2 evolution is 667 µmol/(L·h).
Key words: TiO2; oxygen vacancies; photocatalyst; calcination