Ni–Zn Dual-Atom Sites Enable Synergistic Parallel Pathways for Efficient Photosynthesis of H2O2 with Long-Term Stability

Abstract

The photocatalytic coupling of oxygen reduction (ORR) and water oxidation (WOR) pathways presents a sustainable strategy to supplant the energy-intensive anthraquinone process for H₂O₂ production. However, persistent challenges in radical-mediated catalyst degradation (^•O₂^–/^•OOH/^•OH) and suboptimal charge dynamics continue to plague conventional photocatalytic systems. Herein, we anchored dual-atom Ni–Zn sites onto polymeric carbon nitride (PCN) to prepare an efficient photocatalyst (Ni₁Zn₁-PCN) for photocatalytic H₂O₂ production. Interestingly, using oxygen and water as feedstocks, Ni₁Zn₁-PCN achieves a record yield of 1205.4 μmol g^–1 h^–1 with unprecedented operational stability (>376 h, TON = 2659.6), outperforming best reported catalysts. Mechanism studies revealed that the dual-atom Ni–Zn site could induce charge transfer excitation of the support PCN to suppress electron–hole recombination. In addition, the electronic interaction/modulation in the dual-active sites reduces the activation energy barriers of the WOR and the ORR, thereby achieving a high overall photocatalytic efficiency. This work marks a step forward in the development of efficient and durable photocatalytic H₂O₂ synthesis, offering significant potential for industrial-scale renewable energy applications.