Enlarged interlayer spaced molybdenum disulfide supported on nanocarbon hybrid network for efficient hydrogen evolution reaction

Abstract

We report a facile, one pot solvothermal route to prepare ultrathin molybdenum disulfide supported on nanocarbon hybrid (MoS2@NCHy) network with varied mass loading of MoS2 (20 wt%, 40 wt% and 60 wt%) for catalyzing hydrogen evolution reaction (HER). A large current density of −451 mAcm−2 at an overpotential of −480 mV vs. RHE, proves 40 wt% MoS2@NCHy/GCE nanocomposite as a highly HER active catalytic material. This value was found to be 50 times, 6 times and 2.5 times higher compared to MoS2/GCE (−8 mAcm−2), 20 wt% MoS2@NCHy/GCE (−75 mAcm−2) and 60 wt% MoS2@NCHy/GCE (−180 mAcm−2) respectively. Meanwhile, η10 (overpotential required to attain a current density of −10 mAcm−2) is −186 mV for 40 wt% MoS2@NCHy/GCE, which is much lower to MoS2/GCE (−498 mV), NCHy/GCE (−334 mV), 20 wt% MoS2@NCHy/GCE (−264 mV) and 60 wt% MoS2@NCHy/GCE (−204 mV). The overall activity of the catalyst was manifested by the least overpotential, η10 = −186 mV vs. RHE, Tafel slope of 53 mVdec−1 and exchange current density (j0) of 6.3 × 10−2 mAcm−2. The superior performance of 40 wt% MoS2@NCHy should be attributed to the highly conductive and porous support of three dimensional NCHy architecture as well as the enlarged interlayer spacing of MoS2. This study paves a new paradigm to exploit the synergistic effect of MoS2 and NCHy resulting in strong electronic coupling for enhancement in the HER activity.