Electronic structure regulation of an ultra-thin MOF-derived NiSe/NiS@NC heterojunction for promoting the hydrogen evolution reaction

• Published in: Materials advances Vol. 3; no. 4; pp. 2139 - 2145
• Main Authors: Lu, Kebin, Sun, Jianpeng, Xu, Huakai, Jiang, Chuanhai, Jiang, Weifeng, Dai, Fangna, Wang, Hong, Hao, Hongguo
• Format: Journal Article
• Published: 21.02.2022
• ISSN: 2633-5409
• DOI: 10.1039/d1ma01168e

Transition metal selenides (TMSes) are considered promising electrocatalysts for the hydrogen evolution reaction (HER) due to their narrow bandgap, unique morphology and low cost. Herein, using a metal-organic framework (MOF) as a precursor, a NiSe 2 /NiS 2 @NC electrocatalyst with abundant heterogeneous interfaces was designed and synthesized through a simultaneous selenization/sulfurization process. The heterojunction could provide more catalytic sites, accelerate the transfer of ions/gas, and optimize the electronic structure of the interface, and then exhibit overpotentials of 188 mV and 211 mV at 10 mA cm −2 in acidic and alkaline media. The density functional theory (DFT) calculation results showed that the heterogeneous interface can optimize the electronic structure. Meanwhile, the Gibbs free-energy for H* adsorption was reduced to −0.35 eV, which means that the interface can effectively accelerate the HER kinetics. This work provides a strategy for constructing heterojunction electrocatalysts and understanding the role of electronic structure in the HER. A Ni-MOF is used as a precursor to synthesize a NiSe 2 /NiS 2 @NC heterojunction with rich phase interfaces through a selenization/sulfurization process. Overpotentials of 188 mV and 211 mV are achieved in acidic and alkaline media at 10 mA cm −2 .