Charge Accumulation Engineering in Covalent Organic Frameworks for Enhancing Photocatalytic H2O2 Production.

A charge accumulation strategy in multicomponent covalent organic frameworks (COFs) is developed to maximize photocatalytic H2O2 production. By precisely arranging building blocks into a D-A-A'-A-D configuration, photogenerated electrons from dual donors are funneled and confined at the high-electron-affinity A' center. This spatial convergence creates a localized "electron reservoir" that significantly enhances oxygen adsorption and activation, thereby optimizing the oxygen reduction kinetics at the active sites. Consequently, the charge accumulation D-A-A'-A-D configured representative material COF‑2CN‑2 delivers a H2O2 evolution rate of 6864.68 µmol·g-1·h-1 without sacrificial agents or external oxygen, with an apparent quantum yield (AQY) of 14.13% at 420 nm and a solar‑to‑chemical conversion (SCC) efficiency of 1.27%, which significantly surpasses those obtained with conventional structural arrangements. Notably, it maintains robust photocatalytic activity under natural sunlight in real water. This work offers novel insights into enhancing charge transport within multicomponent COFs and provides a rational design strategy for high‑performance photocatalysts.