Photo‐Self‐Fenton Reaction Mediated by Silver Single Atom and Cluster Photocatalysts for Highly Selective Generation of Singlet Oxygen Toward Efficient Organic Wastewater Treatment

Abstract The persistent organic pollutants in wastewater have caused a heavy threat to ecosystems and humans, but selective removal of these pollutants still faces challenges due to low efficiency, extra addition of oxidation agents, and many highly toxic intermediate products. Herein, we report an efficient, fast kinetic conversion via a photo‐self‐Fenton‐like system of *OOH intermediate‐involved oxidation pathway with a high selection generation of singlet oxygen ( 1 O 2 ) from the novel in situ H 2 O 2 heterolytic activation route for the first time. The single‐atom and cluster‐doped zinc oxide (Ag SA –Ag C /ZnO) was successfully synthesized to achieve the 100% degradation yield and 80% total of carbon (TOC) of the p ‐chlorophenol (4‐CP) as the typical pollutant under solar‐light irradiation and exhibit long‐term activity in a self‐designed photo‐Filter reactor for 4‐CP degradation. It was attributed to the accelerated cycles from Ag high δ+ site to Ag low δ+ site in Fenton‐like catalysis, achieving the rapid selection conversion from the H 2 O 2 heterolytic cleavage to ∼100% 1 O 2 via the intermediate *OOH at the Ag SA sites for ring‐opening reaction and reactive H* at the Ag clusters sites for dechlorination reaction, respectively. This discovery gives the deep understanding of the high‐performance photo‐self‐Fenton reaction through in situ cycles of variable metals for the organic contaminants treatment.