Modulation of Charge Trapping by Island‐like Single‐Atom Cobalt Catalyst for Enhanced Photo‐Fenton‐Like reaction

Abstract Composites‐based photocatalysis relies on the interfacial electron transfer between the metallic cocatalyst and photosensitizer (the semiconductor) to realize spatial separation of charge carriers. Herein, an ingenious heterojunction between Co‐CN single atom catalysts (SACs) and g‐C 3 N 4 is constructed for heterogeneous photo‐Fenton‐like reactions. Driven by built‐in electric field across the heterojunctions, the separation and migration of the photogenerated charge carriers is promoted, leading to the fast electron transfer from the g‐C 3 N 4 to the Co‐CN SACs. Theoretical calculations and transient absorption spectroscopy reveal the modulated charge transfer and trapping in the SA‐Co‐CN/g‐C 3 N 4 heterostructure, resulting in the remarkably enhanced generation of reactive oxygen species via peroxymonosulfate activation under light irradiation. This ingenious SA‐Co‐CN/g‐C 3 N 4 /PMS/vis system is efficient for the oxidation of various antibiotics with high removal efficiency (>98%), a wide operating pH range (pH 3–11) and excellent stability in long‐term operation. This study provides a new tactic for rational design of SACs‐based heterojunctions to bridge photocatalysis and heterogeneous catalysis, attaining superior photoredox activity via interfacial coupling.