Conductive nitrogen-doped carbon armored MOF-derived Fe doped nickel sulfide for efficient oxygen evolution reaction

Abstract

Developing clean energy sources is vital amid the global energy crisis. Hydrogen, emerging as a sustainable energy vector via water electrolysis, mandates adept catalysts owing to the sluggish electrochemical oxygen evolution reaction (OER) kinetics. This work provides a three-step synthesis of Fe-doped NiS2 catalyst from metal-organic frameworks (MOFs). By encapsulating with nitrogen-doped carbon (NC) armor derived from polypyrrole (PPy) through thermal annealing, a novel Fe–NiS2@NC catalyst is achieved for improving the OER performance. The Fe–NiS2@NC demonstrates outstanding prowess, achieves a current density of 10 mA cm−2 with an overpotential as modest as 255 mV, accompanied with a Tafel slope of only 77 mV dec−1. Furthermore, it maintains operational stability for over 40 h under demanding conditions of 50 mA cm−2, displaying an impressive durability compared to the pure NiS2 catalyst. This work combines Fe-doping in NiS2 and PPy-derived NC encapsulation, achieving a dual enhancement of activity and stability of the catalyst. And this strategy also offers a feasible pathway to simultaneously boost the activity and stability in OER electrocatalysts, significantly contributing to clean energy solutions and providing ideas for future research.