Covalent organic framework confined nanocrystals towards interpenetrating heterojunctions for efficient photocatalytic H2O2 production and selective organic catalysis

Abstract

Covalent organic frameworks (COFs) have emerged as a promising photocatalyst for direct H₂O₂ synthesis but suffer from rapid charge recombination and limited visible-light absorption. We developed confined nanoheterojunctions with an interpenetrated network by integrating COFs with ZnCdS via in situ growth, improving visible-light harvesting and promoting effective separation of photogenerated electron–hole pairs through intimate interfacial contact. The optimized heterostructure exhibits an exceptional H₂O₂ production rate of 83 460 μmol g⁻¹ h⁻¹ under visible light, representing a 10-fold and 3-fold increase compared to that of pristine COF (8262 μmol g⁻¹ h⁻¹) and ZnCdS (26 860 μmol g⁻¹ h⁻¹), respectively. Mechanistic studies confirm the primary role of superoxide radicals (˙O₂⁻). Simultaneously, the photocatalyst enables efficient organic transformation, achieving 91.9% conversion in the coupling of thiophenol. This dual functionality bridges artificial photosynthesis and value-added chemical synthesis.