Effective modulation of Ni3S2 by the co-doping strategy of W and Fe enhances the activity and stability for the oxygen evolution reaction

Abstract

The development of transition metal catalysts with low cost and high efficiency plays a significant role in achieving the oxygen evolution reaction (OER) in alkaline electrolysis of water, thereby promoting the rapid development of hydrogen energy. Herein, this paper introduces a simple one-step hydrothermal synthesis method for preparing a Ni₃S₂ catalyst co-doped with W and Fe. It is notable that in the 1 M KOH solution, this electrode has a lower overpotential and faster kinetics. And it shows excellent long-term stability when working continuously for 100 h under 10 mA/cm² conditions. The combination of experimental results and DFT calculations indicates that the synergistic effect of W and Fe optimizes the adsorption in the rate-determining step, and the energy barrier (1.92 eV) is significantly reduced. This progressive barrier reduction quantitatively confirmed the synergistic effect of Fe-W double doping in regulating the electronic structure of the catalyst, thereby accelerating the OER process. In addition, the OER performance of this catalyst is significantly better than that of other transition metal catalysts reported recently. This work not only presents a highly efficient OER catalyst but also provides a universal co-doping strategy that can be extended to other transition metal compounds for advanced energy conversion technologies.