Highly efficient and durable water electrolysis via ligand modulated interfacial assembly

Herein, we report a robust ligand-modulated interfacial assembly strategy for controllable metal doping to yield high-efficiency and durable bifunctional electrocatalysts of FeCoS-embedded hollow N-doped carbon (denoted H-FeCoS/NC) for electrocatalytic overall water splitting (EOWS). Specifically, the hollow Co-based layered double hydroxide (Co-LDH) is employed to render interfacial assembly of CoFe-PBA with tunable composition, morphology, and interface on Co-LDH, regulated by inorganic ligand. Subsequent sulfidation produces H-FeCoS/NC, manifesting outstanding OER/HER activities owing to favourable ligand-modulated Fe-doping, large specific surface area, well-dispersed FeCoS nanoparticles. DFT calculation reveals that ligand-modulated Fe-doping effectively promotes charge transfer, optimizes the intermediates/electrocatalyst interaction, and reduces OER/HER energy barriers, thus boosting the EOWS performance. The H-FeCoS/NC-assembled electrolyzer delivers a low cell voltage of 1.52 V and stably operates for 1000 h in alkaline medium, surpassing most non-noble-metal-based electrocatalysts. This work highlights a facile interfacial assembly route to engineer highly active electrocatalysts for high-performance and durable energy conversion and storage.