Chemically bonded Mn0.5Cd0.5S/BiOBr S-scheme photocatalyst with rich oxygen vacancies for improved photocatalytic decontamination performance

Abstract

Devising exceptional S-scheme heterojunction photocatalysts utilized in annihilating pharmaceuticals and chromium contamination is significant for addressing the problem of global water pollution. In this work, a chemically bonded Mn_0.5Cd_0.5S/BiOBr S-scheme heterostructure with oxygen vacancies is ingeniously developed through a facile in-situ solvothermal synthesis. The designed Mn_0.5Cd_0.5S/BiOBr heterojunction exhibits eminently reinforced photo-activity for destruction of tetracycline hydrochloride and Cr(VI) as compared with its individual components. This substantial photo-redox performance amelioration is benefitted from the creation of an intense internal electric field (IEF) via supplying powerful driving force and migration highway by interfacial chemical bond to foster the S-scheme electron/hole disintegration. More intriguingly, the IEF at the hetero-interface drives the fast consumption of the photo-induced holes in Mn_0.5Cd_0.5S by the photoelectrons from BiOBr, profoundly boosting the enrichment of active photo-carriers and sparing the photo-corrosion of Mn_0.5Cd_0.5S. Furthermore, Mn_0.5Cd_0.5S/BiOBr with exceptional anti-interference property can work efficiently in real water matrices. Multiple uses of the recycled Mn_0·5Cd_0·5S/BiOBr evidence its prominent robustness and stability. This achievement indicates the vast potential of chemically bonded S-scheme photosystems with structural defects in the design of photo-responsive materials for effective wastewater treatment.