Atomic doping on FeNi LDH/CNTs heterostructure electrodes activate lattice oxygen for reversible water splitting

The anion exchange membrane water electrolysis (AEMWE) offers a promising prospect for large-scale hydrogen electro-generation. Nevertheless, current AEMWE is still criticized by large overpotentials and poor anti-reverse current capability of the anodic oxygen evolution reaction (OER). The key challenge lies in tailoring adsorption evolution mechanism (AEM) to lattice oxygen mechanism (LOM), thereby circumventing the overpotential limitation caused by inherent scaling relationship. Here, we designed and fabricated a flexible CC-NCNTs-FeNi catalyst by integrating a hydrophobic carbon nanotube network with hydrophilic FeNi layered double hydroxides (LDH) on carbon cloth (CC), with the interface-induced formations of N-doped LDH and Fe/Ni single-atomic sites. Within lab-made AEMWE setups, the catalyst achieves unprecedented OER performance, rendering 100 mA cm −2 with an overpotential of 250 mV for 100 h. Meanwhile, interface-induced atom exchange endows the catalyst with catalytic multi-functionality, enabling a superior robustness for anti-reverse currents in on-off cycling. The in-situ characterizations and theoretical simulations collectively confirm that N-doping modulates Ni 3 d band center and enhances Ni-O covalency, thus favoring a transition from AEM to LOM-dominated pathway for OER.