Chalcogenic heterostructure supported on carbon nanostructure for electrochemical water dissociation

Abstract

The development of an efficient and stable non-noble metal catalyst to replace noble metal catalyst for hydrogen evolution reaction (HER) is still a challenge. Herein, we report one-step hydrothermal method to synthesis binary hybrid material composed of MoS2/CoS2 heterostructure (HS) supported on reduced graphene oxide (rGO). The coexistence of HS and rGO exhibit lower overpotential towards the HER activity with superior structural stability comparing to MoS2, CoS2 and MoS2/CoS2 under acidic condition. The MoS2/CoS2@rGO yielded a low overpotential of −152 mV at cathodic current density −10 mAcm−2 compared to MoS2, CoS2 and MoS2/CoS2 with values of −322 mV, −537 mV and −238 mV. Also, a low Tafel slope value of MoS2/CoS2@rGO (65 mVdec−1) reflects its superior performance compared to other as-synthesized catalysts. The superior activity of MoS2/CoS2@rGO attributed by conductive support of rGO and strong interaction between HS and water molecule. The avenues of active sites were triggered due to the formation of HS and electrical conductivity enhancement occurred due to the presence of carbon nanostructure, which proves that further engineering of the catalyst can reduce the overpotential drastically.