Zn/ZnO and Zn/ZnO/TiO2 photocatalysts for degradation of Benzene-Toluene-Xylene in aqueous system

Abstract

The aim of the present study is to investigate the catalytic activity of semiconductor materials on the degradation of Benzene-Toluene-Xylene (BTX) in aqueous system under UV light (6 W, λ = 354 nm). Two types of photocatalysts were prepared namely Zn/ZnO and Zn/ZnO/TiO2. Zn/ZnO film was prepared by anodic oxidation of zinc in NaOH with various concentrations. Zn/ZnO deposited with TiO2 photocatalyst was prepared by electrodeposition method. It was found that the optimum concentration for the electrolyte solution (NaOH) was 0.8 M. The pH value of the sample solution had influenced the photocatalytic activity of Zn/ZnO/TiO2 plate in degrading BTX solution. The most suitable pH for the degradation of BTX was pH 6. The most effective degradation of BTX solution using Zn/ZnO/TiO2 plate is 91.54% degradation under four hours of UV irradiation time. The Field Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray spectroscopy (EDX) were applied to study the surface morphology of the Zn/ZnO plate and Zn/ZnO/TiO2 photocatalysts. The large porous surface of Zn/ZnO plate prepared by using 0.8 M NaOH contributed to large amount of TiO2 deposited onto the surface of the photocatalyst and excellent performance of Zn/ZnO/TiO2 on UV-Induced degradation of BTX solution.