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The synthesis of cost-effective and high-performance electrocatalysts for water splitting is the main challenge in electrochemical hydrogen production. In this study, we adopted a high throughput method to prepare bi-metallic catalysts for oxygen/hydrogen evolution reactions (OER/HER). A series of Ni–Mo alloy electrocatalysts with tunable compositions were prepared by a simple co-sputtering method. Due to the synergistic effect between Ni and Mo, the intrinsic electrocatalytic activity of the Ni–Mo alloy electrocatalysts is improved, resulting in excellent HER and OER performances. The Ni 90 Mo 10 electrocatalyst shows the best HER performance, with an extremely low overpotential of 58 mV at 10 mA cm−2, while the Ni 40 Mo 60 electrocatalyst shows an overpotential of 258 mV at 10 mA cm−2 in OER. More significantly, the assembled Ni 40 Mo 60 //Ni 90 Mo 10 electrolyzer only needs a cell voltage of 1.57 V to reach 10 mA cm−2 for overall water splitting. [Display omitted] • A high throughput method was used to prepare Ni–Mo alloy catalysts. • Ni–Mo alloy catalysts exhibit remarkable activity and stability for HER and OER. • The Ni–Mo alloy acts as a bifunctional catalyst for overall water splitting. • The synergistic effect between Ni and Mo leads to the excellent performances. [ABSTRACT FROM AUTHOR]

Exploring highly efficient and robust electrocatalysts to replace the noble metal-based electrocatalysts for alkaline oxygen evolution reaction (OER) is vital and challenging for the conversion of renewable energy. Herein, a novel element incorporation strategy is proposed to synthesize the multi-metallic selenide of (Ni,Fe,Co)Se 2 nanosheets anchored on a stainless steel mesh substrate (NiFeCoSe/SSM). The multi-metallic hybrid film (NiFeCo/SSM) obtained by a co-sputtering method is converted to the (Ni,Fe,Co)Se 2 nanosheets through an alloying-dealloying-selenization process, in which Co and Fe atoms replace part of Ni atoms in the NiSe 2 lattice. The as-obtained NiFeCoSe/SSM displays efficient OER performances in alkaline solutions with an overpotential of 228 mV at 20 mA cm−2 (268 mV at 50 mA cm−2), and a small Tafel slope of 69.8 mV dec−1 in 1.0 M KOH. Furthermore, the NiFeCoSe/SSM electrode demonstrates a remarkable catalytic stability as long as 24.0 h, and its initial nanosheet structure can be well retained after the durability test. Such excellent OER performances of NiFeCoSe/SSM can be attributed to the unique nanosheet structure and the optimized electronic structure due to the synergistic effect among different metallic elements. • A novel element incorporation strategy is proposed to obtain multi-metallic selenide. • Co and Fe atoms replace part of Ni atoms in the NiSe 2 lattice. • The NiFeCoSe/SSM displays efficient OER performances in alkaline solution. • Synergistic effect among metallic elements causes optimized electronic structure. [ABSTRACT FROM AUTHOR]