Oxygen spillover engineering design in atomically dispersed sites for high-efficiency photoproduction of hydrogen peroxide from water

Abstract

The photocatalytic non-sacrificial hydrogen peroxide (H2O2) production is a sustainable and cost-effective approach to solar-driven chemical synthesis, yet its efficiency is fundamentally restricted by the competitive 4e- water oxidation reaction with inefficient kinetics and insufficient atom utilization. Herein, we propose an oxygen spillover strategy to suppress the 4e- water oxidation reaction, in which the O* on metal atom spontaneously migrates and couples with OH* on carbon atom, leading to the formation of OOH* in peroxy-ether intermediates for selective H2O2 synthesis. This new strategy is successful implemented with nickel atom anchored carbon dots/covalent organic frameworks (Ni-CDs/COFs), achieving a record H2O2 evolution rate, an apparent quantum yield and a solar-to-chemical conversion efficiency of 11603 μmol h-1 g-1, 20.4% at 420 nm and 1.56% under simulated sunlight, all outperforming those of most photocatalytic systems in pure water. The oxygen spillover enabled favorable formation of OOH* is further realized on diverse M-CDs with different types of metal atoms, demonstrating the feasibility and universality of proposed strategy. This research opens a window for scalable solar-driven H2O2 production and pioneers an atomic-level design of reaction pathway for efficient photosynthesis system.