KCl-modified g-C3N4 coupled with ZnO to form S-scheme heterojunction photocatalytic materials rich in oxygen vacancies

Photocatalysis involves identifying photocatalysts that exhibit high reactivity, low cost, and environmental friendliness. These catalysts are crucial for achieving energy conversion and for addressing environmental challenges. In this study, we designed and synthesized a novel ZnO/KCl/g-C3N4 photocatalyst enriched with oxygen vacancies through modification and semiconductor coupling. Its photocatalytic degradation rate of methylene blue reached 0.0346/min, which was 7.5 and 9.5 times higher than that of ZnO and g-C3N4, respectively; the composite had a broad spectrum for degrading various organic dyes and antibiotics. Multiple characterizations were performed on the optical characteristics, microstructure, and charge transfer mechanism. This work presents a unique design approach for rationally modifying the local electronic structure of catalysts and developing S-scheme photocatalysis for efficient industrial wastewater treatment. [Display omitted] •For the first time, a unique ZnO/KCl/g-C3N4 photocatalyst was designed and manufactured to degrade a variety of organic contaminants.•This work provides a new idea for rationally changing the local electronic structure of catalysts through modification.•Experimental characterization and mechanistic analysis were used to suggest the mechanism of S-scheme heterojunction photocatalysis.