Novel S-doped BiOBr nanosheets for the enhanced photocatalytic degradation of bisphenol A under visible light irradiation.

Bisphenol A (BPA), a typical endocrine disrupting chemical, is widespread in aqueous environment and cannot be efficiently treated by traditional water treatment technologies. Bismuth oxybromide (BiOBr) is a promising photocatalyst with a special layered structure. However, its band gap (2.8 eV) is not narrow enough for the efficient harvesting of visible light, severely restricting its practical use. Given that the band gap of Bi2S3 is only 1.3 eV, S-doping modification could be used to tailor the band structure of BiOBr. Here, series of S-doped BiOBr nanosheets was prepared through a facile hydrothermal procedure. The as-prepared S0.2-BiOBr nanosheets showed a narrower band gap of 2.33 eV. The intrinsic photocatalytic activity of S0.2-BiOBr sample for the degradation of BPA was 2.78 times higher than that of BiOBr under visible light degradation. Moreover, the mechanism of BPA degradation over the S-doped BiOBr under visible light irradiation was elucidated based on the experimental results and density functional theoretical calculations. Overall, a feasible and effective doping method was proposed to improve the utilization efficiency of visible light.