Resorcinol‐Phthalaldehyde Resins for Photosynthesis of Hydrogen Peroxide: Modulation of Electronic Structure and Integration of Dual Channel Pathway

Abstract Modulating of electronic structure of photocatalyst and integration of dual channel pathway are promising strategy for efficient photosynthesis of hydrogen peroxide (H₂O₂) from pure water without sacrificial agent and oxygen exposure. In this work, nontoxic aromatic dialdehyde is used to replace the commonly used toxic formaldehyde to form resorcinol‐phthalaldehyde resins through a hydrothermal method. The introducing of aromatic ring as π spacer increases the separation distance of electrons and holes to avoid their recombination. H₂O₂ can be produced via integrated oxygen reduction reaction (ORR) and water oxidation reaction (WOR) due to the suitable energy band positions and spatially separated reaction sites. Resorcinol‐p‐phthalaldehyde (RP) resin exhibits a promising H₂O₂ yield of 3351 µmol g⁻¹ h⁻¹ with high apparent quantum yield (AQY) of 14.9% at 420 nm and solar‐to‐chemical conversion (SCC) efficiency of 1.54%. This work provides a simple strategy to modulate the charge separation efficiency and redox reaction pathway on photocatalyst at molecular level design.