Solvothermal synthesis and phase control of nickel sulfides with different morphologies

Nickel sulfides were prepared through a solvothermal process at 190 °C by using NiCl2·6H2O and thiourea as reactants. XRD, XPS and SEM were used to study the phases, compositions and morphologies of the samples. It was found that through changing solvent and molar ratio of thiourea to NiCl2·6H2O, single-phase rhombohedral NiS (r-NiS) and hexagonal NiS (h-NiS) were obtained, NiS2 and Ni3S4 were also observed. r-NiS prepared in different solvents had different morphologies, such as rod-, sphere-, and petal-like.