Construction of a novel S-scheme AgVO/CaInS heterostructure for efficient photodegradation of tetracycline hydrochloride.

Constructing an S-scheme system with highly active catalysts is a significant approach for improving the separation of photoinduced carriers to solve the related environmental aggravation. In this study, a well-designed S-scheme AgVO/CaInS photocatalyst was synthesized for water purification by growing CaInS nanocrystals on AgVO nanorod surfaces. The optimized AgVO/CaInS heterostructure demonstrates an enhanced photocatalytic efficiency (94.1%) toward tetracycline hydrochloride (TCH) degradation compared with bare AgVO (42.6%) and CaInS (81.6%). The significant enhancement of photocatalytic activity is attributed to the S-scheme charge transfer mechanism in the AgVO/CaInS heterostructure, which effectively directs photogenerated charge migration, boosts charge transfer, and preserves the high redox capacity of photoexcited electrons and holes on different active sites. This study is expected to offer insights into strategically designing and preparing S-scheme heterojunction photocatalysts to improve water purification.