High activity Ni-MoS_2-x monolayer nano-sheets fabricated through photo-deposition for highly efficient HER in acid solution

A highly active and stable electro-catalyst for hydrogen evolution was developed by in-situ photo-deposition of Ni metal on MoS2 nano-sheets with many sulfur vacancies. It was found that Ni metal deposition improved the electrical conductivity of MoS2 and further enhanced the catalytic activity by synergistic effect with Ni metal with MoS2 nano-sheets. During photochemical deposition, photo-corrosion moved some sulfur, leading to many sulfur vacancies. Sulfur vacancies further enhance the activity of MoS2 nano-sheets. Electrochemical experiments demonstrate that the catalyst exhibited excellent hydrogen evolution reaction activity with a large cathode current and a Tafel slope as small as 81 per decade. The high hydrogen evolution activity of Ni-doped MoS2 was attributed to synergistic electro-catalytic effects between MoS2 nano-sheets and Ni ions.