Phase-controlled synthesis of nickel sulfide series via solvothermal method

Abstract

Nickel sulfide series nanoparticles were synthesized by a simple solvothermal reduction method of nickel chloride and element sulfur in the oleylamine solvent. This method could offer potential advantages of mildness, safety, low cost, and simplified fabrication procedures. Through the adjustment of Ni / S raw material ratio, different phases of nickel sulfide, including cubic NiS 2, hexagonal NiS , orthorhombic Ni 7 S 6, and trigonal Ni 3 S 2 were obtained. In addition, the sulfur sources played important roles in the synthesis of nickel sulfide series compounds. The possible growth mechanisms had been discussed based on the influence of reaction temperatures and solvents on the phase structure and detailed composition of the final products. Finally, the obtained optical properties demonstrated that each sample had the unique absorption peak except cubic NiS 2.