Interfacial Mo-S bond modulated S-scheme Mn0.5Cd0.5S/Bi2MoO6 heterojunction for boosted photocatalytic removal of emerging organic contaminants

Inefficient photo-carrier separation and sluggish photoreaction dynamics appreciably undermine the photocatalytic decontamination efficacy of photocatalysts. Herein, an S-scheme Mn0.5Cd0.5S/Bi2MoO6 heterojunction with interfacial Mo-S chemical bond is designed as an efficient photocatalyst. In this integrated photosystem, Bi2MoO6 and Mn0.5Cd0.5S function as oxidation and reduction centers of Mn0.5Cd0.5S/Bi2MoO6 microspheres, respectively. Importantly, the unique charge transfer mechanism in the chemically bonded S-scheme heterojunction with Mo-S bond as atom-scale charge transport highway effectively inhibits the photocorrosion of Mn0.5Cd0.5S and the recombination of photo-generated electron-hole pairs, endowing Mn0.5Cd0.5S/Bi2MoO6 photocatalyst with excellent photocatalytic decontamination performance and stability. Besides, integration of Mn0.5Cd0.5S nanocrystals into Bi2MoO6 improves hydrophilicity, conducive to the photoreactions. Strikingly, compared with Mn0.5Cd0.5S and Bi2MoO6, the Mn0.5Cd0.5S/Bi2MoO6 unveils much augmented photoactivity in tetracycline eradication, among which Mn0.5Cd0.5S/Bi2MoO6-2 possesses the highest activity with the rate constant up to 0.0323 min(-1), prominently outperforming other counterparts. This research offers a chemical bonding engineering combining with S-scheme heterojunction strategy for constructing extraordinary photocatalysts for environmental purification. Published by Elsevier B.V. All rights reserved.