Hydrazine-controlled hydrothermal synthesis of Co9S8 from a homogeneous solution

Single-phase nanocrystalline Co9S8 was prepared by hydrothermal treatment o f Co(Ac)(2) and NH2CSNH2 in hydrazine solution at 170 degrees C. The produc ts were characterized by x-ray powder diffraction (XRD) technique, transmis sion electron microscope (TEM), and wet chemical analysis. XRD indicated th e product was the cubic Co9S8 phase. The relative crystallite size was 6.3 nm as determined by the Scherrer method. TEM images showed the particles we re agglomerative. The electron diffraction pattern also revealed their nano crystalline nature. In this hydrothermal formation process of Co9S8, hydraz ine was a critical factor. The formation process is discussed.