Role of graphene in improving catalytic behaviors of AuNPs/MoS2/Gr/Ni-F structure in hydrogen evolution reaction*

The efficient production of hydrogen through electrocatalytic decomposition of water has broad prospects in modern energy equipment. However, the catalytic efficiency and durability of hydrogen evolution catalyst are still very deficient, which need to be further explored. Here in this work, we prove that introducing a graphene layer (Gr) between the molybdenum disulfide and nickel foam (Ni–F) substrate can greatly improve the catalytic performance of the hybrid. Owing to the excitation of local surface plasmon resonance (LSPR) of gold nanoparticles (NPs), the electrocatalytic hydrogen releasing activity of the MoS 2 /Gr/Ni–F heterostructure is greatly improved. This results in a significant increase in the current density of AuNPs/MoS 2 /Gr/Ni–F composite material under light irradiation and in the dark at 0.2 V ( versus reversible hydrogen electrode (RHE)), which is much better than in MoS 2 /Gr/Ni–F composite materials. The enhancement of hydrogen release can be attributed to the injection of hot electrons into MoS 2 /Gr/Ni–F by AuNPs, which will improve the electron density of MoS 2 /Gr/Ni–F, promote the reduction of H 2 O, and further reduce the activation energy of the electrocatalyst hydrogen evolution reaction (HER). We also prove that the introduction of graphene can improve its stability in acidic catalytic environments. This work provides a new way of designing efficient water splitting system.