Quasi-one-dimensional graphene nanoribbon-supported MoS2 nanosheets for enhanced hydrogen evolution reaction

Abstract

Electrolysis of water is a sustainable and environmentally friendly way to produce hydrogen, which has motivated people to develop efficient and earth-abundant electrocatalysts that minimize energy consumption. Herein, graphene nanoribbon@MoS₂ (GNR@MoS₂) hybrids with hierarchical structure have been facilely fabricated as efficient electrocatalysts for the hydrogen evolution reaction (HER). Derived from longitudinally unzipping of multi-walled carbon nanotubes, GNR sheets can provide a greater surface area for the decoration of MoS₂, which not only stems from the outer wall sheets, but also from the additional exfoliated inner wall space, as well as from the unique ribbon edges. Furthermore, the interconnected GNR sheets can form a conductive pathway for fast electron transportation and an open structure for convenient electrolyte permeation. As a consequence, the GNR@MoS₂ hybrids exhibit excellent electrochemical activity as HER catalysts with a low onset potential of −0.11 V vs. the reversible hydrogen electrode and a small Tafel slope of 43.4 mV per decade. The outstanding electrocatalytic performance of the GNR@MoS₂ hybrids can be ascribed to their unique hierarchical architecture with numerous active sites, as well as synergistic effects between the electrocatalytic MoS₂ nanosheets and conductive GNR framework, making them promising materials for future electrocatalysts in the HER.