Fe─N ₅ ‐Induced Coordination Engineering of Mo Single‐Atom: Dual Sites Synergistically Enhancing Photocatalytic H ₂ O _{2 Tongjiao Yin, Fei He, Chao Wang, Siyuan Zou, Wenxin Guo, Haijiao Xie, Qinghai Cai}

The photo‐Fenton technique is a promising strategy for eliminating recalcitrant organic pollutants, coupling photocatalytic two‐electron oxygen reduction (2e ⁻ ORR) for hydrogen peroxide (H ₂ O ₂ ) generation with subsequent activation of H ₂ O ₂ to hydroxyl radicals ( ^• OH) via the one‐electron (1e ⁻ ) Fenton process. To solve the distinct favorable active sites and mismatched selectivity between 2e‒ oxygen reduction reaction and 1e ^‒ Fenton process, we propose a Fe─N ₅ ‐induced coordination engineering strategy of Mo single‐atom to prepare Fe‐Mo _SA /ultra‐thin carbon nitride (UCN) photocatalysts, achieving a H ₂ O ₂ production rate of 2585.40 μmol g ^–1  h ^–1 in pure water under ambient air and >99% degradation of Rhodamine B under natural sunlight. The excellent performance of Fe‐Mo _SA /UCN for H ₂ O ₂ generation and activation thanks to the optimized the charge dynamics and the synergistic effect of dual sites. Theoretical calculations evidence that regulated Mo─N ₃ greatly facilitate O ₂ adsorption and reduce the energy barrier of 2e ⁻ ORR. The generated H ₂ O ₂ spontaneously migrates to the introduced Fe─N ₅ sites for in situ activation to generate ^• OH. Furthermore, outdoor and continuous‐flow experiments also demonstrate the excellent practical applicability of Fe‐Mo _SA /UCN. Overall, this study demonstrates the great potential of dual‐active‐site modulation in advancing photo‐Fenton catalysis, providing atomic‐level insights for designing high‐performance solar energy conversion systems.