A novel 0D/2D/2D hetero-layered nitrogen-doped graphene/MoS2 architecture for catalytic hydrogen evolution reaction

Two-dimensional (2D) layered molybdenum disulfide (MoS2) has emerged as a promising Pt-substituting elec-trocatalyst for the hydrogen evolution reaction (HER) recently. Despite the ever-growing interest in these MoS2 based-materials, their catalytic performance is still far from satisfactory due to the nature of the inactive basal plane and poor conductivity. This work presents a novel nickel@nitrogen-doped graphene@MoS2 (Ni@N-Gr/ MoS2) triad heterostructure for catalytic HER. The as-synthesized Ni@N-Gr/MoS2 assembly exhibits high intrinsic HER activity with a low overpotential of 270 mV at 10 mA cm(-2), an onset overpotential of 60 mV, a small Tafel slope of 56 mV dec(- 1), and robust stability in 0.5 M H2SO4. The notable activity of the Ni@N-Gr/ MoS2 composites is attributed to two main causes (i) presence of further catalytic active sites due to the incor-poration of Ni@N-Gr in the basal plane of MoS2 (ii) improvement of the conductivity due to nitrogen-doped Gr; where a fast electron transfer takes place from Ni@N-Gr core to MoS2 during HER. Our novel-hybrid strategy is promising as an electrochemical platform in industrial hydrogen production and hence can stimulate further structural realizations to employ other metal species.

Automated summary

This work presents a novel nickel@nitrogen-doped graphene@MoS2 (Ni@N-Gr/ MoS2) triad heterostructure for catalytic HER. The as-synthesized Ni@N-Gr/MoS2 assembly exhibits high intrinsic HER activity and stability, thanks to the incorporation of Ni@N-Gr in the basal plane of MoS2 and the improvement of conductivity by nitrogen-doped graphene.