Construction Active Sites in Nickel Sulfide by Dual-Doping Vanadium/cobalt for Highly Effective Oxygen Evolution Reaction

Rational design and exploration of oxygen evolution reaction (OER) electrocatalysts with exceptional performance are crucial for the advancement of the hydrogen energy economy. In this study, vanadium/cobalt (V/Co) dual-doped nickel sulfide (Ni3S2) nanowires were synthesized on a nickel foam (NF) substrate to overcome the sluggish kinetics typically associated with OER. The resulting catalyst exhibited outstanding electrocatalytic activity towards OER in a 1.0 M KOH electrolyte, with a minimal overpotential of 155 and 263 mV, the current densities of 10 and 100 mA cm-2 can be achieved effortlessly. Importantly, this catalyst demonstrated remarkable stability over extended periods, maintaining its performance for 25 h under constant current density, 55 h under continuously varying current density, and even after undergoing 2000 cycles of cyclic voltammetry (CV), which had surpassed those of most non-noble metal electrocatalysts. The X-ray photoelectron spectroscopy and density functional theory analyses confirmed that the co-doping of Co and V redistributed the electron of Ni, leading to improvements in the d-band center, structural characteristics, and free energy landscapes of adsorbed intermediates. This work presents a novel strategy, based on the connection between electronic structure and catalytic properties, in the design of double-doped catalysts for efficient OER.