Electronic structure regulation of an ultra-thin MOF-derived NiSe2/NiS2@NC heterojunction for promoting the hydrogen evolution reaction†
*a
Abstract
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 NiSe2/NiS2@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.
Please wait while we load your content...
