Activating the alkaline hydrogen evolution performance of Mo-incorporated Ni(OH)2 by plasma-induced heterostructure

Nickel-based metal oxides/hydroxides are promising electrocatalysts for oxygen evolution reaction. However, their electrocatalytic activity for hydrogen evolution reaction (HER) is very poor. Herein, taking Mo-incorporated nickel hydroxide (Mo-Ni(OH)2) as an example, a facile, time-efficient, and low-temperature H2/N2 plasma activation strategy is developed to activate the HER performance by constructing heterostructure. This kind of heterostructure is composed of metal, metal alloy, metal nitride, and oxygen vacancy-riched metal hydroxide with more exposed catalytically active sites, enhanced mass activity, and accelerated electron transport. The optimized plasma-activated Mo-Ni(OH)2 (P-Mo-Ni(OH)2) manifests superior HER performance to pristine Mo-Ni(OH)2 and even comparable to the benchmark Pt/C catalyst in alkaline solution. Moreover, when assembling a two-electrode urea-assisted water electrolysis system by using P-Mo-Ni(OH)2 as both cathode and anode, the assembled cell only need a small voltage of 1.36 V to achieve a current density of 10 mA cm−2 and exhibits extremely stable catalytic performance up to 1000 h.