Nickel sulfides supported by carbon spheres as efficient catalysts for hydrogen evolution reaction

Ni3S2 and NiS supported on carbon spheres are successfully synthesized by a facile hydrothermal method. And then a series of physical characterizations included XRD (X-ray diffraction), EDS (energy dispersive spectroscopy), FESEM (field emission scanning electron microscopy) and XPS (X-ray photo-electron spectroscopy) were used to analyze the samples. XRD was used to confirm that Ni3S2 and NiS were successfully fabricated. FESEM indicated that Ni3S2 and NiS disperse well on carbon spheres. Electrochemical tests showed that nickel sulfides supported by carbon spheres exhibited excellent hydrogen evolution performance. The excellent catalytic activity is attributed to the synergistic effect of carbon spheres and transition metal sulfides, of which the carbon spheres act to enhance the electrical conductivity and the dispersion of Ni3S2 and NiS, thus providing more active sites for the hydrogen evolution reaction