Microplastic degradation by hydroxy-rich bismuth oxychloride

Highlights: • A novel hydroxy-rich ultrathin BiOCl was prepared at room temperature. • Hydroxy-rich ultrathin BiOCl has a great enhancement of microplastics degradation. • Surface hydroxyl of BiOCl can enhance the production of hydroxyl radicals. • Hydroxyl radicals play a key role in the microplastics degradation. Microplastics, as a class of widely dispersed persistent pollutants, the main reactive oxygen species is far from clarified in their photocatalytic degradation. In this study, a novel hydroxy-rich ultrathin BiOCl (BiOCl-X) was prepared at room temperature. BiOCl-X shows a strong potential for photocatalytic degradation of microplastics, and the mass loss of plastics is 24 times higher than that of the BiOCl nanosheets. More importantly, we explored the photocatalytic mechanism through electron paramagnetic resonance and capture experiments, and found that the surface hydroxyl of BiOCl can effectively enhance the production of hydroxyl radicals, resulting in boosting degradation performance. Here, we provide new insights that photocatalytic degradation of microplastic is dependent on surface hydroxyl groups. This work could be useful for controllable designs of hydroxy-rich photocatalysts for applications in microplastic degradation.