CoS2/MoS2 decorated with nitrogen doped reduced graphene oxide and multiwalled carbon nanotube 3D hybrid as efficient electrocatalyst for hydrogen evolution reaction

Abstract

Designing an efficient and stable electrocatalyst made of earth abundant elements to take over expensive noble metal based for Hydrogen Evolution Reaction (HER) have been focused. Cobalt disulfide-molybdenum disulfide nanocomposite supported by nitrogen doped reduced graphene oxide and multiwalled carbon nanotubes (CoS2/MoS2@NrGO-MWCNT) is reported as an efficient electrocatalyst for HER. CoS2/MoS2@N-rGO-MWCNT and ternary hybrids composed of CoS2, MoS2 and N-rGO/MWCNT have been investigated. The catalysts were prepared by facile hydrothermal method, and the optimal doping ratio referred to date cobalt to molybdenum as 2:1 was chosen. It is found that co-existence of CoS2, MoS2 brings abundant active sites and incorporation of MWCNT offered stability. Good dispersion of CoS2 nanoparticles on graphene and MoS2 sheets is observed. Additionally nitrogen doping on rGO sheets has been carried out to boost up the electronegativity of the catalyst as a support to enhance the catalytic activity of CoS2/MoS2 for refine structure and better electrical conductance. Precisely, CoS2/MoS2@N-rGO-MWCNT exhibited smaller tafel slope 73 mV dec−1 at overpotential 281 mV for current density 10 mA cm−2 and the substantial stability of 14 h is recorded in 0.5 M H2SO4 medium, results suggest that catalyst is viable alternate for HER.