Unique Sillén-structured multimetal high entropy oxyhalide PbxCd1-xBiO2Br with enhanced photocatalytic activity

Based on the typical Sillén-structured bimetallic oxyhalide layered structure, the introduction of the crystal structure of a high entropy semiconductor photocatalyst allowed the formation of a novel Sillén-structured multimetal high entropy oxyhalide materials with metal cooperativity. A Sillén-structured multimetal high entropy oxyhalide PbxCd1-xBiO2Br material was designed, possessing both ultrathin layered structure of Sillén-structured metal oxyhalides and typical advantages of high stability and more active sites for high entropy alloys. The transfer path of photogenerated electrons is narrowed, and their migration and separation are significantly improved. The catalytic activity was investigated through the photocatalytic degradation of organic pollutants. As verified by ESR and radical trapping experiments, hole (h+) and superoxide radical (O2−) were proved to be the principal active species during photocatalysis. In this paper, we propose a scheme to combine a high entropy alloy with a Sillén-structured bimetallic oxyhalide and successfully construct a Sillén-structured multimetallic high entropy oxyhalide PbxCd1-xBiO2Br material, which will provide a new direction for the development of Sillén-structured bismuth-based systems.