Asymmetric Janus FeCu dual atom catalysts enabling synergistic visible-light activation of periodate

Combining visible-light-driven periodate (PI) activation with dual atom catalysts (DACs) offers a promising yet challenging strategy for removing recalcitrant organic pollutants such as antibiotics. However, the functional homogeneity of conventional DACs remains a research bottleneck requiring breakthroughs. Herein, a highly asymmetric (FeN₂O₂CuNO) Janus FeCu-pCN catalyst was designed. Benefiting from charge redistribution and efficient carrier separation induced by this structural asymmetry, the catalyst exhibits outstanding activity. The optimized FeCu-pCN efficiently activates PI under visible light, achieving complete degradation of SD within 15 min. Experimental and DFT calculations reveal that the asymmetry introduced by Cu redistributes charge density and shifts the Fe d-band center toward the Fermi level, thereby enhancing PI adsorption. A stable and efficient electron-transfer pathway exists within FeCu-pCN, spanning from the SD to Fe site to O bridge to Cu site. Mechanistically, the Fe center functions as an oxidation pole, anchoring SD molecules and mediating direct h⁺ oxidation, while the Cu center serves as a reduction pole, facilitating localized e^- transfer and PI activation through its highly unsaturated coordination structure. This atomic-level division of labor spatially decouples the redox processes, maximizing the synergistic interaction between the dual sites and enabling efficient pollutant degradation. This work provides new insights into the rational design of high-performance DACs for activation of PI.