Hydrogen evolution reaction catalyzed by MoS2/CoS2 supported on nanocarbon hybrid in acidic medium

Abstract

There is a high demand for evolving cost-operative and efficient non-noble electrocatalysts for hydrogen evolution reaction (HER). Free-standing MoS2 and their heterostructures are emerging as potential electrocatalysts due to their electrochemical stability in harsh acidic mediums. Herein, we report a one-pot hydrothermal synthesis of MoS2/CoS2 heterostructure with and without the support of carbon nanostructures. The electrical conductivity of the support material is enhanced by introducing f-MWCNT, which acts as pillars between the rGO layers, thus exposing a larger quantity of active sites that favors the hydrogen adsorption property and reduces the charge transfer resistance for facilitating the HER kinetics. The interfacial interaction between MoS2 and CoS2 with the synergistic effect of rGO/f-MWCNT (nanocarbon hybrid, NCHy) results in a potential catalyst yielding a current density of −10 mA/cm2 at −133 mV with an exchange current density value of 0.34 mA/cm2 and turnover frequency of 1.33/s. Catalyst stability is examined using a chronoamperometry test (CA) for 14 h, and the material shows high stability. Also, a study of change in electrochemical activity with change in transition metal in the heterostructure is systematically performed.