Visible light-induced photocatalytic degradation of tetrabromobisphenol A on platinized tungsten oxide.

In this study, we investigated the degradation of the flame retardant tetrabromobisphenol A (TBBPA) using platinized tungsten oxide (Pt/WO), synthesized via a simple photodeposition method, under visible light. The results of degradation experiments show a significant enhancement in TBBPA degradation upon surface platinization of WO, with the degradation rate increasing by 13.4 times compared to bare WO. The presence of Pt on the WO surface stores conduction band electrons, which facilitates the two-electron reduction of oxygen and enhances the production of valence band holes (h) and hydroxyl radicals (OH). Both h and OH are significantly involved in the degradation of TBBPA in the visible light-irradiated Pt/WO system. This was verified through fluorescence spectroscopy employing coumarin as a chemical probe and oxidizing species-quenching experiments. The analysis of degradation products and their toxicity assessment demonstrate that the toxicity of TBBPA-contaminated water is significantly reduced after Pt/WO photocatalysis. The degradation rate of TBBPA increased with increasing Pt/WO dosage, reached an optimum at a Pt content of 0.5 wt%, but decreased with increasing TBBPA concentration. The decrease in degradation efficiency of Pt/WO was minor, both in the presence of various anions and after repeated use. This study proposes that Pt/WO is a viable photocatalyst for the degradation of TBBPA in water under visible light.