Ni-MOF precursor assisted formation of vanadium doped nickel sulfide nanorods for boosting the electrocatalytic oxygen evolution reaction

Abstract

The rational design of high-efficiency electrocatalysts for the oxygen evolution reaction (OER) is crucial for the development of water electrolysis technology. In this study, a vanadium-doped nickel metal–organic framework (Ni-MOF) precursor was synthesized on nickel foam (NF) via a facile hydrothermal approach. Subsequently, a sulfidation strategy was employed to fabricate a vanadium-doped nickel sulfide (V–Ni₃S₂)/NF electrocatalyst, specifically tailored for alkaline OER applications. The V–Ni₃S₂/NF electrocatalyst demonstrated remarkable performance, demanding an overpotential of merely 273 mV to achieve a current density of 10 mA cm⁻². Coupled with a Tafel slope of 56.67 mV dec⁻¹, the catalyst exhibited exceptional durability, maintaining stability over a 24-hour testing period. The distinctive nanorod architecture of the catalyst endows it with a substantial active surface area, while the nickel foam substrate significantly reduces the charge transfer resistance at the electrolyte interface, thereby expediting electron transport kinetics. Notably, the introduction of vanadium serves as a key modulator, effectively tuning the electronic structure of nickel active sites and significantly enhancing the OER catalytic activity. Post-stability analysis further confirmed the structural robustness of the catalyst, validating its practical applicability. This study presents an innovative and efficient approach for the rational design of high-performance OER catalysts, offering valuable perspectives for the broader implementation of energy conversion technologies.