[Hydrothermal synthesis of Co9S8 nanocrystalline aggregations and spectral study]

Co9S8 nanocrystalline aggregations were synthesized in hydrazine hydrate (N2H4 x H2O) solvent at 180 degrees C for 12 h through a hydrothermal method using cobalt sulfate hydrate (CoSO4 x 7H2O) and sodium sulfate (Na2SO3) as the starting materials. The prepared samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), and transmission electron microscope (TEM). FTIR spectrum was measured using Fourier-transform infrared spectrometer. The results showed that the products were mainly composed of Co9S8 hexagonal flakes, which were about 2.1 microm in diameter and 200 nm in thickness. The flakes consisted of Co9S8 nanocrystallites with an average size of 2.5 nm.