Characterization of photocatalyst Bi 3.84 W 0.16 O 6.24 and its photodegradation on bisphenol A under simulated solar light irradiation

Bismuth tungsten oxide Bi 3.84 W 0.16 O 6.24 was prepared by hydrothermal process under pH 12. Both the hydrothermal reaction temperature and time affected the crystallinity and morphology of the prepared catalysts, which in turn affected their degradation efficiency. Although all the prepared catalysts showed adsorption in the visible region around 450 nm, the catalyst synthesized at 140 °C for 20 h displayed the highest photocatalytic degradation capacity to bisphenol A (BPA) under simulated solar light irradiation due to the combination of its good crystallinity and perfect disk morphology. In the photodegradation system of BPA and Bi 3.84 W 0.16 O 6.24, no OH was detected by electron spin resonance analysis, suggesting that direct hole is predominant in the degradation of BPA by Bi 3.84 W 0.16 O 6.24. It displayed high photocatalytic degradation and mineralization capacities to BPA as compared with P25 TiO 2 under simulated solar light irradiation. The analytical results of both LC–MS and GC–MS demonstrated that no hydroxylated intermediates were formed. A simple and direct photodegradation pathway of BPA by Bi 3.84 W 0.16 O 6.24 was proposed by the analysis of intermediates.