Interfacial electron redistribution stabilizes Cu-centered redox cycling for efficient Fenton-like catalysis

Interfacial electronic coupling drives Cu-site-selective electron enrichment. • Electron-rich Cu centers facilitate rapid Cu 2+ /Cu + redox interconversion. • Regulated ROS evolution enables robust 1 O 2 -enriched Fenton catalysis. Efficient degradation of organic pollutants via Fenton-like catalysis remains a challenge due to the instability of the redox cycle under prolonged operation. Herein, we construct an interface-engineered FeCu layered double hydroxide/g-C 3 N 4 heterostructure (FeCu-LDH/g-C 3 N 4 ) to establish an internal electron-supply pathway for stabilizing Cu-centered redox cycling. Spectroscopic analyses, together with DFT calculations, support interface-induced electron redistribution, which favors electron depletion in the g-C 3 N 4 framework and preferential electron enrichment at Cu sites, promoting partial Cu 2+ reduction to Cu + , while Fe 3+ remains largely stable as a structural and electronic modulator. Benefiting from this site-selective electronic regulation, FeCu-LDH/g-C 3 N 4 exhibits markedly accelerated H 2 O 2 activation and achieves near-complete Rhodamine B degradation within 20 min, with a pseudo-first-order rate constant 4.6 times that of pristine FeCu-LDH. Active-site substitution confirms Cu as the primary redox center, while ROS quenching and electron paramagnetic resonance analyses identify 1 O 2 as the dominant oxidative species, accompanied by •OH and O 2 •- . The catalyst further shows robust recyclability, broad pH adaptability, and strong tolerance to humic substances and common ions. This work demonstrates a Cu-site-selective interfacial electron-regulation strategy for designing stable and efficient Fenton-like catalysts. Download: Download high-res image (414KB) Download: Download full-size image