Highly efficient degradation of chlorophenol over bismuth oxides upon near-infrared irradiation: Unraveling the effect of Bi-O-Bi-O defects cluster and 1O2 involved process

Chlorophenols (CPs) treatment in water is a huge challenge due to its native robustness and harmful chlorinated by-products in degradation. In this work, we developed a specific BiO2-x with high density Bi-O-Bi-O vacancy via a facile hydrothermal process. Extraordinary CPs removal ability under near infrared (NIR, >700 nm) is achieved over the as-prepared product. The presence of vacancies not only induced strong interactions between CPs and photocatalyst, but also promoted singlet oxygen (1O2) and photogenerated holes (h+) generation. Furthermore, the generated 1O2 is found mainly originating from lattice oxygen release and the superoxide radicals (O2−) oxidation from BiO2-x. Such performance could be well-maintained under wide pH range as well as in the presence of different constitutes in water matrix. This work unravels a unique function of BiO2-x photocatalyst for CPs decomposition and provide a rational design of highly efficient photocatalysts toward optimization of pollutants degradations.