The Synthesis of Nickel Sulfide Nanoparticles on Graphitized Carbon Supports

Nickel metal nanoparticles supported on graphitized carbon have been reacted with H 2 S/H 2 gas mixtures to produce catalytic nickel sulfide nanoparticles. By varying the conditions of H 2 S concentration, reaction time, and reaction temperature, nanoparticles of β-Ni 3 S 2, Ni 9 S 8, Ni 7 S 6, and β-NiS have been selectively produced. The average particle size was found to increase with conversion of the nickel metal particles to nickel sulfide particles with values that agreed with those obtained from density calculations. The phases formed were characterized by PXRD, HRTEM, and EDX and at 300 °C were those predicted from previous experiments on bulk samples. However, at 600 °C, the low-temperature phases β-Ni 3 S 2, Ni 9 S 8, and Ni 7 S 6 formed rather then the higher temperature phases adopted by bulk samples at this temperature.