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.