Ni3S2@Ni3Se2 electrocatalysts for enhanced hydrogen and oxygen evolution reaction

Abstract

Developing cost-effective and robust non-noble metal bifunctional electrocatalysts is critical for sustainable hydrogen production via electrochemical water splitting. However, the practical application is often restricted by the sluggish kinetics and high energy barriers of both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we synthesize highly efficient and stable Ni3S2@Ni3Se2 catalysts with rod-shaped structure through a two-step hydrothermal route. Benefiting from the synergistic effect of the composite structure, the optimal Ni3S2@Ni3Se2-3 samples present the overpotential of 248 mV @ 50 mA cm-2 for oxygen evolution reaction (OER) and 91 mV @ 10 mA cm-2 for hydrogen evolution reaction (HER). Meanwhile, the two-electrode system shows a voltage of 1.58 V at 50 mA cm-2. Our work provides a feasible strategy to design other non-noble metal catalysts with high catalytic activity.