Transition metal dichalcogenide materials: Solid-state reaction synthesis of nanocrystalline nickel disulfide

One novel and convenient synthetic approach has been proposed to prepare the transition metal dichalcogenide material of nanocrystalline nickel disulfide (NiS2) by the solid-state reaction between basic nickel carbonate and elemental sulfur at 400 °C. The as-synthesized product is characterized by X-ray powder Diffraction (XRD), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and Low-temperature N2 Adsorption (BET method). TEM micrographs show that the as-synthesized NiS2 has nanostructures with the average particle size of 48 nm. The sulfur-to-nickel ratio of the sample determined by XPS is 1.70, which indicates that the surface of the sample is rich in Ni4+. The probable formation mechanism of nanocrystalline NiS2 is discussed in this manuscript.