The sluggish kinetics of electrocatalysts in the alkaline
hydrogen
evolution reaction (HER) is a critical challenge to attain efficient
progress in water electrolysis for carbon-neutral hydrogen production.
Here, we present a high-performance and durable heterostructure of
NiMo/CoMoO4 for the alkaline HER constructed via a two-pot
in situ growth strategy on a nickel foam (NF). The density of active
sites and the surface area of the hybrid catalyst augmented almost
three-fold compared to those of pristine CoMoO4. The heterostructure
composed of metallic NiMo and oxygen vacancy (Ov)-confined
CoMoO4 facilitated the H adsorption on the metallic side
and OH adsorption on the oxide side. The hierarchical hybrid catalyst
on NF featured a low overpotential of 102 mV at 10 mA cm–2, approaching that of platinum on carbon (83 mV) in 1.0 M KOH. The
turnover frequency of 0.012 s–1 at the overpotential
of 100 mV of NiMo/CoMoO4 is six times higher than that
of CoMoO4, 0.002 s–1. In addition, the
fabricated heterostructure is a highly durable HER catalyst at 30
mA cm–2 for 30 h. The Faradaic efficiency recorded
by a gas chromatograph at 10 and 100 mA cm–2 revealed
nearly 100 and 86–95% hydrogen production efficiency, respectively.