Ni3S2@Ni3Se2 electrocatalysts for enhanced hydrogen and oxygen evolution reactions

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 the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we synthesize highly efficient and stable Ni₃S₂@Ni₃Se₂ catalysts with a 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 OER and 91 mV@10 mA cm⁻² for 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.