Graphene-coated hybrid electrocatalysts derived from bimetallic metal–organic frameworks for efficient hydrogen generation

Abstract

In this study, we synthesized a low-cost electrocatalyst, Ni/Mo₂C nanoparticles coated with graphene shells (denoted as NiMo₂C@C), via a facile carburization process of porous bimetallic metal–organic frameworks (NiMo-MOF). This is the first example of a Ni and Mo₂C nanocomposite derived from a bimetallic MOF that demonstrates excellent electrocatalytic activity and remarkable durability as long as 10 h under acidic and basic conditions. The overpotentials are 169 mV and 181 mV to reach the current density of 10 mA cm⁻², respectively. The favorable performance can be ascribed to the synergistic effect between Mo₂C and Ni as well as the homogeneous distribution, graphene coating and mesoporous structure which is in favor of the charge transfer in the HER. This work may provide some guidelines for fabricating nanostructured hybrids composed of versatile transition metal carbides and graphene with high performance and stability in different media based on designed MOFs.