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Free keywords:
Epitaxial growth, Hydrogen evolution reaction, Ni3S2/NiS heterojunction, Nickel sulfide based electrocatalysts, Water electrolysis, Charge transfer, Electrocatalysts, Electrolysis, Epitaxial growth, Heterojunctions, Interface states, Nanowires, Nickel, Nickel sulfates, Potassium hydroxide, Precious metals, Clean energy, Electrochemicals, Energy economy, Hydrogen evolution reactions, Hydrogen-evolution, Ni3S2/NiS heterojunction, Nickel foam, Nickel sulphide based electrocatalyst, One-dimensional, Water electrolysis, Sulfur compounds
Abstract:
Hydrogen evolution reaction (HER) over the non-noble metal-based electrocatalysts is a promising approach to realize future clean energy economy. Herein, to achieve effective interface construction, epitaxial growth of NiS on the surface of one-dimensional (1D) Ni3S2 nanowire on nickel foam (NF) was performed, to construct a Ni3S2/NiS electrocatalyst with a heterojunction structure via a solid-state phase transformation. Benefiting from the strong charge transfer at the Ni3S2/NiS heterojunction interface, the d-band center was downshifted compared to the single component (Ni3S2 or NiS), which effectively optimized the valence state and the H adsorption of Ni, thus improved the HER activity. The obtained Ni3S2@NiS-250/NF showed the robust HER catalytic performance with a low overpotential of 129 mV to deliver the current density of 10 mA cm−2 with a small Tafel slope (75.5 mV dec-1) in 1 M KOH media. Moreover, it exhibited superior durability for at least 50 h. This work provides a novel strategy for designing nickel sulfide-based catalysts for HER with high performance. © 2022 Elsevier Ltd
