Non‐Radical Mediated Photocatalytic H2O2 Synthesis in Conjugate‐Enhanced Phenolic Resins with Ultrafast Charge Separation

It is essential for the development of highly efficient polymeric photocatalysts for hydrogen peroxide (H2O2) production. Nevertheless, the non-uniform molecular structures and sluggish reaction pathway of polymeric photocatalysts lead to low conversion efficiency. In this work, we report sulfur-contained phenolic resins with regulated conjugation for photocatalytic H2O2 production. Due to the substitution of sulfur for methylene in the phenolic resin structure, the conjugation degree of the material is adjusted, resulting in the formation of a built-in electric field. This effectively enhances the charge separation capability, enabling charge carriers to react faster with substrates. Through in-situ characterization and theoretical calculations, we have unveiled that the introduction of sulfur can modulate the reaction pathway of phenolic resin materials, enabling a dual-pathway photocatalytic H2O2 production mediated by non-radical species. Impressively, the sulfur-contained resin photocatalyst showcases exceptional H2O2 production activity with a solar-to-chemical conversion efficiency of 1.4% exceeding most reported systems, and generates 25 mmol m-2 of H2O2 under natural sunlight through large-scale equipment. This work provides a facile strategy to separate the photogenerated electron-hole pairs of polymer photocatalysts to achieve efficient artificial photosynthesis.