Enhanced Hydrogen Evolution Catalysis at the Liquid/Liquid Interface by NixSy and NixSy/Carbon Nanotube Catalysts

NixSy (NiS and Ni17S18) nanoparticles and their nanocomposite with carbon nanotubes (NixSy/CNT) were synthesized by a modified hydrothermal method and characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and energy-dispersive X-ray microanalysis. The synthesized materials were used as hydrogen evolution catalysts at the water/1,2-dichloroethane interface by using decamethylferrocene as a lipophilic electron donor. The hydrogen evolution reaction in biphasic systems was investigated by two-phase reactions and by cyclic voltammetry with a four-electrode system. A kinetic study of the hydrogen production was also performed. The rates of the reactions catalyzed by the NixSy nanoparticles and the NixSy/CNT nanocomposite were found to be about 690-fold and 2000-fold higher, respectively, than the rate for the reaction performed in the absence of a catalyst.