NiSe₂/Ni₃Se₄ dual-phase electrocatalysts are synthesized by calcining the Ni(OH)₂ nanosheets on Ni foam and Se powder under an N₂ atmosphere. The Ni’s charge-state, phase compositions, and electrocatalytic performances are dependent on the initial mass ratios of Ni to Se. The experimental results demonstrate that the electrocatalyst with a higher Ni charge-state and more Ni₃Se₄ phase facilitates oxygen evolution reaction (OER), whereas the one with a lower Ni charge-state and more NiSe₂ phase boosts hydrogen evolution reaction (HER). Density functional theory calculations reveal that the interfacial electrons transfer from Ni₃Se₄ to NiSe₂, which improves conductivity and optimizes adsorption/desorption energies. NiSe₂/Ni₃Se₄/NF-4 containing more NiSe₂ phase displays the best HER activity while NiSe₂/Ni₃Se₄/NF-1 containing more Ni₃Se₄ phase shows the best HER activity. The electrolyzer, employing NiSe₂/Ni₃Se₄/NF-4 and NiSe₂/Ni₃Se₄/NF-1 as the cathode and anode, respectively, performs the full potential and demonstrates a low voltage of 1.56 V achieving 10 mA cm⁻² with good durability.

NiSe ₂ /Ni ₃ Se ₄双相电催化剂是通过在 N ₂气氛下在泡沫镍和硒粉上煅烧 Ni(OH) ₂纳米片来合成的。Ni 的电荷态、相组成和电催化性能取决于 Ni 与 Se 的初始质量比。实验结果表明，具有较高 Ni 电荷态和更多 Ni ₃ Se ₄相的电催化剂促进析氧反应（OER），而具有较低 Ni 电荷态和更多 NiSe ₂相的电催化剂促进析氢反应（HER） ）。密度泛函理论计算表明，界面电子从 Ni 转移₃ Se ₄到 NiSe ₂，可提高电导率并优化吸附/解吸能。含有较多NiSe ₂相的NiSe ₂ /Ni ₃ Se ₄ /NF-4表现出最好的HER活性，而含有较多Ni ₃ Se ₄相的NiSe ₂ /Ni ₃ Se ₄ /NF-1表现出最好的HER活性。电解槽，采用NiSe ₂ /Ni ₃ Se ₄ /NF-4和NiSe ₂ /Ni ₃ Se ₄/NF-1 分别作为阴极和阳极，发挥全电位并显示出 1.56 V 的低电压，可实现 10 mA cm ^-2并具有良好的耐久性。