Photocatalytic degradation performance and mechanism of tetracycline by Pd-loaded titanium dioxide

Abstract

The development of effective and environmentally safe photocatalysts for the removal of antibiotics from aquatic environments remains an important issue. In this work, materials with different metal Pd mass loading ratios were prepared by loading TiO2 with noble metal Pd after the introduction of oxygen vacancies. After the photocatalytic degradation of TC, it was found that the 0.5% Pd/TiO2-Vo photocatalyst showed good photocatalytic activity in the degradation of tetracycline, with a degradation efficiency of 95.04% in 2 h and a reaction rate constant 2.18 times higher than that of TiO2. It was found that the introduction of oxygen vacancies and Pd loading could enhance the visible light response to overcome the drawback that TiO2 could only be irradiated by UV while increasing the free carrier density and inhibiting electron-hole recombination to improve its photocatalytic degradation efficiency. Finally, the possible decomposition pathways and degradation products of TC were inferred by combining liquid chromatographymass spectrometry (LCMS). The findings of this work may provide a new approach to improving the photocatalytic activity of TiO2.