Heterostructure engineering of self-supported bimetallic sulfide as an efficient bifunctional electrocatalyst for overall water splitting

Abstract

The exploitation of effective bifunctional electrocatalysts for oxygen and hydrogen evolution reactions (OER, HER) is of great significance to hydrogen energy production via electrocatalytic water splitting. Herein, a self-supported Ni3S2/NiMo2S4-POM/NF hybrid heterostructure with uniform flower-like nanosheets and highly porous for overall water-splitting was synthesized via a scalable hydrothermal method followed by a vulcanization treatment. Significantly, the obtained three-dimensional porous heterostructure with high structural integrity ensures sufficient exposure of active sites and effectively adjusts the electronic structure for faster charge carrier dynamic to achieve enhanced reaction kinetics. The as-prepared Ni3S2/NiMo2S4-POM/NF achieves low overpotentials of 275 and 338 mV to deliver a current density of 100 mA cm−2 for OER and HER. Furthermore, the assembled alkaline electrolyze comprised of Ni3S2/NiMo2S4-POM/NF for both anode and cathode exhibits an appealing voltage of 1.53 V at 10 mA cm−2 with excellent long-term durability, implying notable catalytic activity of Ni3S2/NiMo2S4-POM/NF towards overall water-splitting. This work sheds light on a simple approach for synthesizing highly efficient electrocatalysts for water electrolysis.