Construction of medium-entropy alloys coupled Z-Scheme heterojunction and its enhanced photocatalytic performance by regulating mechanism of LSPR effect

Abstract

Optimizing the local surface plasmon resonance (LSPR) effect of non-noble metals through alloying has been crucial for improving its practical application in the field of photocatalysis. Rare studies capture the detail that the change in the electronic structure of metal elements caused by alloying affects plasma carrier concentration and the local surface plasmon resonance effect. Herein, NiCuCoFe medium-entropy alloys (MEAs) nanoclusters were designed and used to modify the Bi3O4Br/CNNs Z-scheme heterojunction. The cocktail effect of MEAs causes the 3d-orbital hybridization of various metal elements, which promotes the release of charge carriers. The higher the carrier concentration, the stronger the LSPR effect of MEAs. In addition, the mechanism of three typical working pathways of the LSPR effect to improve the photocatalytic performance of heterojunction is discussed. And compared with those of Bi3O4Br, CNNs, and Bi3O4Br/CNNs, the rate constant of MEAs-Bi3O4Br/CNNs was 3.26, 11.16, and 3.17 times higher during the degradation of norfloxacin, respectively. This study provides a new strategy for understanding the mechanism of LSPR and the rational design of plasmonic coupling architectures for enhanced photocatalysis.