MoS₂ Nanosheets on MoNi₄/MoO₂ Nanorods for Hydrogen Evolution

Abstract

Active\nelectrocatalytic electrodes have been long searched as potential\nalternatives to platinum-free electrodes for the hydrogen evolution\nreaction (HER). Here, we report the development of a hybrid nanostructure\nof two-dimensional (2D) MoS₂ nanosheets grown on MoNi₄/MoO₂ nanorods as a synergistic nanostructure for\nthe hydrogen evolution reaction. The nanostructure is unique as it\nis composed of vertically grown few-layer atomically thin MoS₂ nanosheets supported on MoNi₄/MoO₂ nanorods\nwith an extraordinarily high surface area. Structural and morphological\ncharacterizations illustrate that the 2D MoS₂ nanosheets\nwere uniformly coated on the MoNi₄/MoO₂ nanorods\nvia a facile hydrothermal process. The distinct phase formation, surface\ncompositions, and bonding states confirm the structural integrity\nand compositional homogeneity between MoS₂ and MoNi₄/MoO₂ nanorods in the synergistic nanostructures.\nElectrochemical characterizations showed that the MoS₂:MoNi₄/MoO₂ electrodes exhibited a narrower Tafel slope\n(67 mV dec^–1) and a lower overpotential (η₁₀ = 155.6 mV) compared to the pristine MoS₂, thereby\naccelerating hydrogen evolution reactions in an alkaline medium. Also,\nthe synergistic nanostructure-based electrode showed faster charge\ntransport for the HER compared to pristine 2D MoS₂ while\nexhibiting a higher number of the catalytically active sites for the\naccelerated charge transfer process. The synergistic MoS₂:MoNi₄/MoO₂ nanostructure electrode shows more\nthan 8 h stability with enhanced HER performance.