Photocatalytic degradation of gaseous benzene with CdS-sensitized TiO2 film coated on fiberglass cloth

In this paper, TiO2 film coated on fiberglass cloth was synthesized by sol-gel method and further sensitized by CdS nanoparticles using a sequential chemical bath deposition technique. Gaseous benzene was adopted as a model pollutant to evaluate the photocatalytic performances of the supported TiO2 films sensitized with variable content of CdS nanoparticles, which obtained by adjusting the concentration of Cd2+ or S2- precursor solution. Along with the increase of the CdS amount, the photocatalytic activity of these samples initially increases and then shows a downward trend. When the concentration of Cd2+ or S2- precursor solution achieved 0.005 M, the sample performs the best photocatalytic property and the degradation efficiency reaches 92.8% and 32.7% under UV-vis and visible light irradiation, respectively. The enhancement of the photocatalytic activity could be attributed to the formation of micro-heterojunction. However, a thick CdS sheath covered catalyst surface will form when high concentration of Cd2+ or S2- solution is used. The low photogeneraied electron-hole pairs separation efficiency and the photocorrosion process of CdS decrease the photocatalytic activity gradually. (c) 2012 Elsevier B.V. All rights reserved.