Heterostructure of 3D sea-grape-like MoS2/graphene on carbon cloth for enhanced water splitting

Abstract

MoS2 has been widely used as a hydrogen evolution reaction (HER) electrocatalyst because of its unique characteristics, such as a tunable band gap, near-zero Gibbs free energy, and earth abundance. However, its low electrical conductivity and the electrochemically inert basal plane of MoS2 decrease the HER performance. Herein, we used graphene and carbon cloth (CC) to boost the electrocatalytic activity of MoS2. Using nickel electrodeposition and chemical vapor deposition (CVD) at high temperature, graphene was grown on carbon cloth (Gr/CC) and a sea-grape-like morphology was formed simultaneously. Finally, Gr/CC was covered up with MoS2 using two-zone CVD (MoS2/Gr/CC), resulting in a three-dimensional (3D) sea-grape-like heterostructure. The MoS2/Gr/CC exhibits outstanding HER performance, with a suitable onset potential (50 mV), low ŋ10 (91 mV, overpotential at 10 mA cm−2), high electrical double layer capacitance (Cdl; 239 mF cm−2), low Tafel slope value (48 mV dec−1), and high stability in 0.5 M H2SO4 for two days at various overpotentials. The 3D sea-grape-like morphology and the synergistic effect of MoS2 and graphene led to the enhanced electrocatalytic activity of MoS2/Gr/CC, indicating much better HER performance than most electrocatalysts based on graphene and MoS2.