Abstract
The electrocatalytic activity of transition metal sulfides is strongly correlated with the active edge sites and conductivity of the catalysts. Here we developed a hybrid nanowire structure consisting of NiS2-MoS2 interlaced nanoflakes by the thermal conversion of nickel molybdate (NiMoO4) nanowire precursors. The obtained NiS2-MoS2 interlaced nanoflakes have sub-200 nm sizes with abundant active edge sites and defects, as well as synergistic nanoscale interfaces between NiS2 and MoS2 throughout the whole structure. The hetero-nanowires exhibit superior hydrogen evolution reaction (HER) catalytic activity including a low onset potential of 76 mV and a small Tafel slope of 70 mV dec(-1) in a 1 M KOH aqueous solution, which substantially exceeds those of most of the metal sulfide HER catalysts including individual NiS2 and MoS2 nanostructures in basic solutions.