Rationally design and exploration of bifunctional electrocatalysts with excellent performance towards water splitting is significant for hydrogen energy economy. Herein, a novel Au/Ni₃S₂ heterostructure catalyst that was composed of self-supported Ni₃S₂ nanosheets decorated with Au nanoparticles on Ni foam was fabricated. The bifunctional catalyst exhibited excellent catalytic activities towards oxygen evolution reaction (230 mV@10 mA cm^-2) and hydrogen evolution reaction (97 mV@10 mA cm^-2) in 1 M KOH. The electrolytic tank using the bifunctional catalyst only required 1.52 V to deliver 10 mA cm^-2 and sustained for 60 h, outperforming most of advanced bifunctional catalysts. The X-ray absorption fine structure (XAFS) and density functional theory (DFT) calculations validated that the strong electronic coupling at the interface could modulate the electronic structure of Ni₃S₂, thereby optimizing the free energies of the adsorbed intermediates. This work provides an atomic-scale insight into the structure-properties relation of a promising heterostructure catalyst for water splitting.

合理设计和探索具有优异水分解性能的双功能电催化剂对于氢能经济具有重要意义。在此，制备了一种新型的 Au/Ni ₃ S ₂异质结构催化剂，该催化剂由在泡沫镍上装饰有 Au 纳米颗粒的自支撑 Ni ₃ S ₂纳米片组成。该双功能催化剂在1 M KOH中对析氧反应(230 mV@10 mA cm ^-2 )和析氢反应(97 mV@10 mA cm ^-2 )表现出优异的催化活性 。使用双功能催化剂的电解槽仅需1.52 V 提供 10 mA cm ^-2并持续 60 小时，优于大多数先进的双功能催化剂。X射线吸收精细结构（XAFS）和密度泛函理论（DFT）计算验证了界面处的强电子耦合可以调节Ni ₃ S ₂的电子结构，从而优化吸附中间体的自由能。这项工作提供了对有前途的异质结构水分解催化剂的结构-性质关系的原子级洞察。