An efficient CoS2/CoSe2 hybrid catalyst for electrocatalytic hydrogen evolution

Abstract

Herein we established a robust and highly efficient catalyst for the hydrogen evolution reaction (HER), with the characteristic of CoS₂ nanoparticles dotted on the surface of CoSe₂/DETA (DETA = diethylenetriamine) nanobelts (CoS₂/CoSe₂). The CoSe₂/DETA nanobelts possess intrinsic high conductivity and superior electrocatalytic activity. In addition, the evenly distributed amino groups on the surfaces of CoSe₂/DETA nanobelts contribute to copious nucleation sites, which are in favor of easy nucleation, uniform dispersion, and size control of CoS₂ nanoparticles. Owing to the prominent synergistic effect between CoS₂ nanoparticles and CoSe₂ nanobelts, the CoS₂/CoSe₂ hybrid exhibits a superior HER activity with a small overpotential of 80 mV at a cathodic current density of 10 mA cm⁻², and a small Tafel slope of 33.6 mV dec⁻¹ in acidic media. Meanwhile, the catalyst shows excellent mechanical stability.