Lattice matching Fe₃P-Cu₃P heterointerfaces for efficient hydrogen evolution reaction in alkaline and seawater media

The production of hydrogen via water/seawater electrolysis is economically promising but faces challenges due to the insufficient activity and durability of catalysts. Herein, theoretical calculations indicate that Fe₃P-Cu₃P facilitates charge density redistribution at the heterointerfaces, thereby enhancing adsorption behaviors and speeding up the dynamics of hydrogen evolution reaction (HER). Subsequently, the Fe₃P-Cu₃P heterointerface on Ni Foam is effectively established through lattice-matching approach. Remarkably, owing to the enhanced intrinsic activity and favorable reaction kinetics, this heterostructure demonstrates outstanding catalytic performance for electrocatalytic HER (40 and 61 mV at 10 mA/cm²) in alkaline fresh and alkaline seawater. Moreover, its superior catalytic stability is verified through cyclic voltammetry (CV) over 3000 cycles and a durability test lasting more than 50 h. Additionally, it demonstrates significant potential application in alkaline water splitting via an integrated solar-to‑hydrogen system. This work provides valuable insights into the development of advanced electrocatalysts featuring heterointerfaces.