Preparation of Visible-Light-Responsive TiO2 Doped Ag Thin Film on PET Plastic for BTEX Treatment

Abstract

This study aims to develop a visible-light responsive thin film for treatment of gaseous pollutants such as Benzene, Toluene, Ethylbenzene and Xylene (BTEX). Silver (Ag) doped titanium dioxide (Ag/TiO₂) thin films were synthesized via sol-gel method with different Ag contents. The thin film was formed by dip coating on polyethylene terepthalate (PET) substrate before activating with UV lamp. The X-ray diffractograms demonstrated the heterogeneous phase between anatase crystal of TiO₂ and nanosilver. The shift of the wavelength absorption edge to visible light was observed on the composite film due to a decrease of band gap energy. The photocatalytic activity of the thin films was evaluated by the decolorization of 10^-5 M methylene blue (MB) dye and the degradation of 25 mg/l gaseous BTEX. The thin film containing Ag/Ti molar ratio as 0.1 exhibited 80% decolorization of methylene blue and 79, 82, 86, 88% degradation of BTEX under visible light, respectively. Thus, the Ag/TiO₂ thin film coated on PET substrate can be applied for dye treatment as well as indoor air treatment.