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

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 Mn0.5Cd0.5S/BiOBr S-scheme heterostructure with oxygen vacancies is ingeniously developed through a facile in-situ solvothermal synthesis. The designed Mn0.5Cd0.5S/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 Mn0.5Cd0.5S by the photoelectrons from BiOBr, profoundly boosting the enrichment of active photo-carriers and sparing the photo-corrosion of Mn0.5Cd0.5S. Furthermore, Mn0.5Cd0.5S/BiOBr with exceptional anti-interference property can work efficiently in real water matrices. Multiple uses of the recycled Mn0·5Cd0·5S/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. A flower-like Mn0.5Cd0.5S/BiOBr S-scheme heterojunction with interfacial Bi–S bonds and oxygen vacancies (OVs) is synthesized through a simple solvothermal route. Under the synergistic cooperation of S-scheme heterostructure, interfacial Bi–S bonds and OVs, Mn0·5Cd0·5S/BiOBr displays exceptional photocatalytic properties toward Cr(VI) reduction and tetracycline hydrochloride oxidation under visible light irradiation. [Display omitted] •Chemically bonded Mn0.5Cd0.5S/BiOBr S-scheme photocatalyst with rich OVs was devised;•Mn0.5Cd0.5S/BiOBr exhibited superior photocatalytic decontamination of Cr(VI) and antibiotics;•The synergy of S-scheme junction, interfacial chemical bonding, and OVs leads to the activity optimization;