Heterogeneous Bimetallic Mo-NiPx/NiSy as a Highly Efficient Electrocatalyst for Robust Overall Water Splitting

Highly efficient electrocatalysts composed of earth-abundant elements are desired for water-splitting to produce clean and renewable chemical fuel. Herein, a heteroatomic-doped multi-phase Mo-doped nickel phosphide/nickel sulfide (Mo-NiP x /NiS y ) nanowire electrocatalyst is designed by a successive phosphorization and sulfuration method for boosting overall water splitting (both oxygen and hydrogen evolution reactions (HER)) in alkaline solution. As expected, the Mo-NiP x /NiS y electrode possesses low overpotentials both at low and high current densities in HER, while the Mo-NiP x /NiS y heterostructure exhibits high active performance with ultra-low overpotentials of 137, 182, and 250 mV at the current density of 10, 100, and 400 mA cm −2 in 1 m KOH solution, respectively, in oxygen evolution reaction. In particular, the as-prepared Mo-NiP x /NiS y electrodes exhibit remarkable full water splitting performance at both low and high current densities of 10, 100, and 400 mA cm −2 with 1.42, 1.70, and 2.36 V, respectively, which is comparable to commercial electrolysis.