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

Abstract

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 0.005M, 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 photogenerated electron–hole pairs separation efficiency and the photocorrosion process of CdS decrease the photocatalytic activity gradually.