Design of hierarchical integration superbranched Ni–S clusters for efficient, stable hydrogen production

Abstract

Transition metal sulfides (TMSs), especially iron-based metals (Fe, Co, Ni), were considered the most potential catalysts to replace noble metal-based materials for hydrogen evolution reaction (HER). This work selected metal ions as a variable to modulate the catalytic activity. Designing an electrode consisting of iron-based metal atoms sulfides sweeper-like hyperbranched clusters grown on nickel foam (NF) for HER. This particular structure consisted of 1D nanorods and adequate exposure of the lattice dislocation to exhibit enhanced electrocatalytic activity with low overpotential (135.9 mV) in alkaline conditions at 10 mA cm−2. In addition, stability test results showed that the electrode exhibited good durability. The enhanced electrocatalytic activity of Ni–S could be owing to high electrical conductivity characteristic, the hierarchical structure constituted with NF and the large active surface area of the self-grown electrode further facilitating the production of H2. The Ni sites on the Ni3S2 (110) crystal faces facilitated H adsorption, and all radical reactions under applied voltage proceed spontaneously. This work guides the selection and development of substrates for the design of synthetic transition metal catalysts, leading to cost-effective and efficient electrocatalytic hydrogen production.