Interface-engineered 2D perovskite/SnS2 heterojunction photocatalysts for enhanced selectivity in glycerol oxidation

Solar-driven conversion of glycerol to valuable chemicals is a promising approach for reducing carbon footprint and contributing to eco-economic sustainability. However, the activity of photocatalytic glycerol oxidation is far from the satisfactory of practice requirement. Therefore, we report an O-defect-engineered 2D CsPbBr 3 /SnS 2 heterostructure photocatalyst via oxygen-assisted heat treatment and self-assembly method. This approach enhances the photoactivity and selectivity for the oxidation of glycerol to glycolic acid, achieving a yield of 12.4 mmol mg cat −1 h −1 and a selectivity of 87 %. The yield and selectivity of glycolic acid reaches 257.3 mmol mg cat −1 h −1 and 100 %, respectively, after adjusting the pH of reaction system. The experimental and theoretic analyses reveal that the O-defect-engineered heterostructure accelerates charge transfer and separation. X-ray photoelectron spectroscopy and in situ X-ray absorption spectroscopy disclose that Sn atom is the active site and the interfacial electric field accelerates the charge transfer from SnS 2 to CsPbBr 3 , thereby enhancing glycerol oxidation at the Sn site. Additionally, trapping experiments indicate that superoxide and hydroxyl radicals are crucial in the glycerol oxidation process. This work demonstrates a catalyst that enables highly selective glycerol-to-glycolic-acid conversion and provides in-depth insight into the evolution of catalytic sites, positioning a promising candidate for sustainable chemical manufacturing. • Development of interface-engineered 2D perovskite/SnS 2 heterojunction photocatalysts for enhanced performance. • Investigation of the charge transfer mechanism at the heterojunction interface. • Elucidation of the relationship between radical species and product selectivity. • Monitoring the dynamic evolution of active sites during catalytic reactions.