Di-nuclear metal synergistic catalysis: Ni2Mo6S6O2/MoS2 two-dimensional nanosheets for hydrogen evolution reaction

MoS2, an inexpensive non-noble metal catalyst, has emerged as a promising cathode material for water electrolysis. However, the limited number of reactive sites within the basal plane seriously restricts its hydrogen evolution performance. Herein, to create more reactive sites, Ni is successfully intercalated into the framework of MoS2 and Ni2Mo6S6O2/MoS2 two-dimension nanosheets are obtained. The Ni2Mo6S6O2/MoS2 shows significant improved catalytic performance with lower overpotential (0.09 V at 10 mA cm−2) than the MoS2 counterpart. Moreover, it could generate hydrogen at a current density of 250 mA cm−2 with no activity decline over 24 h. In-situ shielding/oxidation experiments and theoretical calculations prove that Ni and Mo perform synergistic catalytic activity on Ni2Mo6S6O2 for the decomposition of H2O. The strategy of designing di-nuclear synergistic catalysts provides a promising avenue for developing Hydrogen evolution reaction (HER) catalysts by active sites engineering.