Transition metal dichalcogenides (TMDs) such as MoS2 and MoSe2 are promising to replace Pt-based catlaysts for hydrogen evolution reaction (HER). However, the catalytic activity of TMDs is hindered by their inert basal plane and high inter-layer resistance. In this study, we investigated the effect of Ni alloying on the catalytic properties of MoSe2 thin films in HER. Ni-Mo-Se ternary chalcogenide thin films having different Ni content (9-50 at. %) were fabricated by the thermal selenization of the sputter deposited Ni-Mo alloy thin films. Ni alloying was found to notably enhance the catlaytic performance of the MoSe2. Among the catalyst films, Ni-Mo-Se at 33 at.% Ni concentration exhibits the highest catalytic activity with an overpotential of 349 mV at 10 mA/cm2 current density and a Tafel slope of 58 mV/dec. The enhanced HER performance of the Ni-Mo-Se catalysts can be ascribed to three main factors:1) Ni addition alters the electronic structure of MoSe2, leading to a more favorable Gibbs free energy of hydrogen adsorbtion value and therefore activating the basal plane. 2) Ni induces a doping effect in the MoSe2, resulting in a lower charge transfer resistance. 3) Ni prevents the oxidation of Se atoms on the surface of the MoSe2.
Anahtar Kelimeler: catalyst, hydrogen evolution reaction, MoSe2, doping, Ni