NiSe2/FeSe2 heterostructured nanoparticles supported on rGO for efficient water electrolysis

Abstract

Development of a cost-effective and highly abundant catalyst for overall water splitting is highly desirable. Herein, we report a feasible approach to fabricate a catalyst based on phase-separated heterointerfaces in which heterostructured NiSe₂ and FeSe₂ are supported on a reduced graphene oxide composite (NiSe₂/FeSe₂/rGO), which may improve the intrinsic properties of materials. The as-prepared catalyst shows excellent oxygen evolution reaction (OER) (260 mV@10 mA cm⁻²), hydrogen evolution reaction (HER) (101 mV@10 mA cm⁻²) and total water splitting (1.57 V@10 mA cm⁻²) activities in alkaline solution. The NiSe₂/FeSe₂/rGO catalyst also exhibits fast charge transfer ability, long-term stability and a large electrochemically active surface area. The multi-metal active sites generate a remarkable synergistic effect and carbon channels also support electron transmission during the water splitting process. This work provides a new perspective to analyze the role of heterostructure-based materials in the water electrolysis.