Exfoliated MoS2 with porous graphene nanosheets for enhanced electrochemical hydrogen evolution

Porous graphene (P-rGO) was synthesized from graphene oxide (GO) via a one-pot calcination method with CO 2 as an activation agent at 800 °C. Due to the special porous structure , the surface area of P-rGO can be increased to ∼759 m 2 /g. The P-rGO was then used as a support to incorporate with chemical exfoliated molybdenum disulfide (MoS 2 ) for the fabrication of MoS 2 /P-rGO composite. Compared to bulk MoS 2 , the exfoliated MoS 2 is in the 1T phase with a metallic property and smaller charge transfer resistance , thus has a better activity in electrochemical hydrogen evolution reaction (HER). The HER activity of 1T MoS 2 could be further increased after the combination with P-rGO. The overpotential of 1T MoS 2 /P-rGO was only ∼130 mV vs. RHE , and the corresponding Tafel slope was ∼75 mV Dec −1 . The special porous structure and good electric conductivity of P-rGO decrease the charge transfer resistance of the composite without sheltering too many active sites of MoS 2 , thus leading to the enhanced HER activity. As an efficient noble metal free HER catalyst, the 1T MoS 2 /P-rGO has great potential for large-scale hydrogen production .