Co9S8 nanotubes: facile synthesis and application in the catalytic reduction of 4-nitrophenol

Co9S8 nanotubes have been successfully synthesized via a facile two-step solvothermal method without the assistance of any template or surfactant, using cobalt sulphate (CoSO4⋅7H2O), urea and sodium sulphide (Na2S⋅9H2O) as starting reactants, and deionized water and glycol as the reactive medium. The phase and the morphology of the as-obtained product were characterized by means of powder X-ray diffraction, energy dispersive spectrometry and scanning electron microscopy. The result displays that the Co9S8 nanotubes have hexagonal cross-sections, the diameter of the nanotubes is about 200 nm and the wall thickness is of 50 nm. The experiments showed that the Co9S8 nanotubes could be used as new-type catalysts for the reduction of 4-nitrophenol. It was found that the as-obtained Co9S8 nanotubes contributed to the best catalytic activity.