Facet-induced charge transfer and photocatalytic performance of an S-scheme hybrid heterojunction composed of porous g-C₃N₄ nanosheets and WO₃ nanorods with exposed high-energy (0 0 1) facets

Crystal facet engineering has been demonstrated to be a flexible technique that significantly improves photocatalyst performance by promoting interfacial charge transfer and separation. In this study, we systematically coupled porous polymeric carbon nitride nanosheets (PCN) and WO₃ nanorods with exposed (0 0 1) facets (WO_AT) to fabricate a WO_AT@PCN hybrid photocatalyst with improved photocatalytic properties. Importantly, the fabricated WO_AT@PCN hybrid catalyst demonstrated significantly enhanced performance for the degradation of oxytetracycline and naproxen pollutants under visible light compared to PCN, WO_AT, and WO_ST with different exposed facets. Furthermore, the hybrid catalyst demonstrated excellent stability and reusability across multiple test runs. The remarkable photodegradation performance of the hybrid catalyst is primarily attributable to the intrinsically high surface area and charge separation properties of the (0 0 1) facets of WO_AT, enhanced visible light absorption, and S-scheme charge transfer at the interface, promoting photoexcited charge separation and enhancing the redox capabilities of the separated photoexcited electrons and holes. In addition, total organic carbon (TOC) analysis confirmed the efficacy of mineralization, while liquid chromatography/tandem mass spectrometry (LC/MS/MS) studies revealed the potential degradation pathways of sample pollutants. This study elucidates the systematic design of hybrid catalysts using crystal facet engineering for various photocatalytic applications.