B-ZnxCd1-xS/Cd Heterojunction with Sulfur Vacancies for Photocatalytic Overall Dyeing Wastewater Splitting

Designing highly efficient multifunctional photocatalysts and coupling with a valuable and thermodynamically favorable oxidation reaction can make full use of photogenerated charge carriers. Herein, a facile synthesis route is developed to obtain a boron-doped ZnxCd1-xS/Cd heterojunction with sulfur vacancies (B-ZCS(v)/Cd-T) via NaBH4 treatment. The optimized B-ZCS(v)/Cd-T catalyst achieved a superior activity toward hydrogen evolution (5.10 mu mol) due to coupling with RhB degradation (87.48%) in dyeing wastewater under visible light. Systematic investigation reveals that NaBH4 treatment resulted in boron doping and simultaneously sulfur vacancies in B-ZCS(v)/Cd-T, which consequently optimized the energy band structures to form a B-ZCS(v)/Cd heterojunction, leading to (i) effective absorption of visible lights and (ii) enhanced separation/transfer efficiency of the photogenerated carriers. This work provides an effective strategy to increase the photocatalytic activity of catalysts via modulating band structures and interfacial compatibility of the heterojunction and especially through coupling with a valuable and more thermodynamically favorable reaction.

Automated summary

In this study, a boron-doped ZnxCd1-xS/Cd heterojunction with sulfur vacancies was synthesized via NaBH4 treatment. The optimized catalyst achieved a superior activity towards hydrogen evolution and RhB degradation in dyeing wastewater under visible light, due to the optimized energy band structures and enhanced separation/transfer efficiency of the photogenerated carriers.