Pt-like catalytic behavior of MoNi decorated CoMoO3 cuboid arrays for the hydrogen evolution reaction

Abstract

The major challenges encountered in the search for the replacement of Pt group materials toward the hydrogen evolution reaction (HER) in alkaline electrolytes are the stabilities and sluggish kinetics of non-noble metal electrocatalysts. MoNi has exhibited considerably higher catalytic activity than MoNi₂, MoNi₃ and MoNi₄ in alkaline electrolytes; however, there are no reports on the application of MoNi to the HER. Herein, we report for the first time the construction of MoNi nanoparticle decorated CoMoO₃ cuboid arrays of vertical growth using Ni foam as the scaffold (MoNi/CoMoO₃/NF). Owing to the high catalytic activity of MoNi nanoparticles, the interaction between different phases, the ability to increase the active sites of CoMoO₃ cuboids and the synergistic effect on the whole, the MoNi/CoMoO₃/NF exhibits high stability and activity with zero onset overpotential and a low Tafel slope of 35 mV dec⁻¹, and only 18 mV is needed to afford 10 mA cm⁻² in 1 M KOH, which is even better than that of the state-of-the-art Pt/C catalyst. Density functional theory calculations demonstrate that the CoMoO₃ and MoNi in MoNi/CoMoO₃ synergistically enhanced water splitting activity. Our findings provided a new idea to integrally construct non-noble metal catalysts with outstanding HER performance surpassing that of noble metals.