Coupled compressive-tensile stains boosting both activity and durability of NiMo electrode for alkaline water/seawater hydrogen evolution at high current densities

The development of NiMo-based electrode with superior activity and durability at high current densities to meet industrial requirements for hydrogen production in alkaline water/seawater still remains a great challenge. Herein, an edge dislocation strain-boosted Ni₃Mo integrated electrode (D-Ni₃Mo/NF) is reported. The remarkable coupled tensile-compressive strain effect induced by dense edge dislocations not only inhibits oxidative dissolution of Mo from Ni₃Mo in alkaline electrolyte, but also simultaneously optimizes the electronic structure of dual active sites (Ni and Mo), which boost both durability and activity of D-Ni₃Mo in catalyzing alkaline hydrogen evolution reaction (HER). Consequently, D-Ni₃Mo/NF only requires overpotentials as low as 15 and 232 mV to achieve 10 and 1000 mA cm⁻² in 1 M KOH, respectively, and exhibits ultralong-term stability for 200 h at 500 mA cm⁻², outperforming most of recently reported NiMo-based catalysts. It also shows distinguished HER activity in seawater electrolysis with superior stability at 500 mA cm⁻².