Nanoporous Ni3S2 Film on Ni Foam as Highly Efficient Electrocatalyst for Hydrogen Evolution in Acidic Electrolyte

Abstract

In this work, nanoporous Ni₃S₂ film (Ni₃S₂/Ni) is in situ synthesized by direct sulfurization of Ni foam under a mild hydrothermal process. Surprisingly, it is found out that the obtained Ni₃S₂/Ni exhibits outstanding HER activity and excellent stability in acidic electrolyte. The structure and nature of the Ni₃S₂/Ni are analyzed with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field emission scanning electron microscope (FE-SEM). On Ni₃S₂/Ni, the onset potential is only −6.23 mV (vs. RHE) while the large exchange current density is 790 µA cm⁻² and the Tafel slope is 62.47 mV dec⁻¹. The experimental results demonstrate the potential of Ni₃S₂/Ni for its replacement of Pt-based catalysts.