Atomic coordination engineering and pollutants synergy co-modulate self-motivated single-atom catalysis with...

Green Fenton-like reaction based on the single-atom dual-reaction-center systems represents a novel water treatment strategy that achieves low-energy consumption and zero-oxidant consumption. However, its core mechanism based on the single-atom configurations and pollutant types remains unclear. In this study, an in-depth exploration was conducted on the performance and mechanism of the self-motivation Fenton-like reactions (without the external oxidants) by systematically investigating iron single-atom catalysts (SACs) with different configurations (Fe/N_x-SAC, x = 5, 4, 3) and pollutants with various electronic properties. The results indicated that the Fe/N_x-SAC exhibited strong electron-accepting capabilities for extracting electrons from the pollutants to initiate the self-motivated pathway primarily based on single-atom iron reduction/oxidation. Additionally, this self-motivated pathway could be further co-regulated by the coordination environments of SACs and electron-donating characteristics of pollutants. (i) Distinct coordination environments in Fe/N_x-SAC exhibited differential electron-accepting capacities, directly governing their electron extraction capability for modulating iron-mediated self-motivation pathways; (ii) pollutants with higher electron-donating capacity could significantly improve electron-transfer efficiency and accelerate iron single-atom reduction/oxidation. This work provided a strategy to establish self-motivated Fenton-like systems with sustainable oxidation capacities and pathways for pollutant decontamination.