Mo-rich rGO–2H–MoSe2 nanocomposites with novel crystal growth plane of (106) for high hydrogen evolution reaction activity

Abstract

In this study, MoSe2-reduced graphene oxide (rGO) nanocomposites with novel crystal growth plane of (106) of 2H–MoSe2 nanosheets were modified as working electrode for enhancement of hydrogen evolution reaction (HER). Versatile characterizations revealed that rGO as a template evolves the crystal growth of MoSe2 nanosheets to (106) atomic plane while inducing an amorphous type structure at the same time. XPS studies identified the Mo rich structure and the increase of the contribution of Mo6+ oxidation state in rGO-MoSe2 structure with broad full width at half maximum (FWHM) characteristic of Mo 3d peaks and the 0.4–0.6 eV shift of Se 3d to higher binding energies resulting in the defective MoSe2 nanosheets. Polarization measurement studies revealed a small Tafel slope of 49 mV.dec−1, onset potential of 52 mV and low over potential of 271 mV at J = 100 mA cm−2 for HER. In addition, it was found that the weight ratio of MoSe2 and rGO has a critical role in the cyclic stability of the nanocomposite in HER activity.