Powder metallurgy synthesis of porous NiMo alloys as efficient electrocatalysts to enhance the hydrogen evolution reaction

Highlights: • Porous NiMo alloys were prepared by microwave sintering coupled with Mg space holder. • It has a low overpotential and a low Tafel slope. • NiMo phase can serve as active sites and reduce the charge transfer resistance. • After CV-activation, the Ni(OH)₂ nanosheets can be formed. -- Abstract: Electrochemical water splitting is considered to be one of the most potential strategies to achieve the hydrogen economy. In this paper, the porous NiMo alloys used as efficient electrocatalysts were designed and synthesized by microwave sintering powder metallurgy method. The as-prepared porous NiMo alloys as good electrocatalysts exhibit excellent hydrogen evolution reaction (HER) performance and outstanding durability in alkaline electrolyte (1.0 M KOH). Especially, the porous Ni₆Mo₄ alloy shows smaller overpotential of 37 mV at current density of 10 mA cm⁻² and a low Tafel slope of 82.1 mV dec⁻¹. The efficient electrocatalytic performance of Ni₆Mo₄ alloy can be attributed to the synergies of Ni, Mo and NiMo intermetallic compound, more active sites and quicker charge transfer rate.