MOF-derived nickel–cobalt nanostructures for high-performance electrocatalytic hydrogen evolution reaction

Abstract

Metal-organic frameworks (MOFs) are promising materials for energy-related applications, but their poor electrical conductivity limits their potential in electrocatalysis. In this study, p-Ni_xCo_1-x-MOF cathode catalysts were synthesized via a hydrothermal method followed by low-temperature annealing. This approach preserves the organic ligands within the MOF structure while exposing metal particles, thereby improving conductivity. The resulting catalyst demonstrates remarkable hydrogen evolution reaction (HER) performance, achieving an overpotential of only 35 mV and 142 mV at a geometric current density of 10 mA cm⁻² and 300 mA cm⁻², respectively, with a small Tafel slope of 34.78 mV dec⁻¹, along with excellent long-term stability that p-Ni_0.8Co_0.2-MOF enabled sustained electrolysis at current densities of 10 mA cm⁻² and 100 mA cm⁻² for one week, compared with the MOF-based catalysts used for hydrogen evolution in recent years, the performance is excellent. The low-temperature annealing maintains the integrity of the organic framework and induces beneficial surface modifications, increasing the number of active sites and enhancing reaction kinetics and electron transfer efficiency for the superior electrocatalytic performance of the catalysts.