Novel Photocatalytic Ag/TiO2 Thin Film on Polyvinyl Chloride for Gaseous BTEX Treatment

Abstract

This study aims to provide the photocatalytic approach for treatment of some hazard air pollutants such as benzene, toluene, ethylbenzene and xylene (BTEX) under visible light. Silver doped titanium dioxide (Ag/TiO2) thin films with various molar ratios (0.01, 0.05, 0.1 and 0.2 mol) were synthesized via sol-gel method and dipped on polyvinyl chloride (PVC) sheet before curing with UV lamp. The X-ray diffractograms showed the composite of TiO2anatase and nanosilver. The effect of silver doping on decreasing of band gap energy of TiO2was observed from the absorption edge shift to higher wave length, analyzed by UV-visible spectrometer. The results from hydrophilicity test indicated that hydrophilicity of TiO2thin film was increased by doping silver. The morphology of the Ag/TiO2thin film studied by Scanning Electron Microscope equipped with an Energy Dispersive Spectrometer revealed well dispersed nanosilver on the smooth thin film. The BTEX degradation was carried out in a batch reactor with the initial concentration of mixed BTEX gas [25 ppm]. The remaining BTEX was examined by Gas Chromatography equipped with flame ionization detector. Among Ag/TiO2thin films, the 0.1 Ag/TiO2thin films exhibited the best performance for gaseous BTEX degradation under visible light. The maximum degradation efficiency was belong to xylene (89%), followed by ethylbenzene (86%), toluene (83%) and benzene (79%).