Nanocrystalline Co9S8 has been successfully prepared by a hydrothermal-redu
ction method at 120 degrees C. The reducing agents were produced from dispr
oportionation of white phosphorus in alkaline medium. X-ray diffraction pat
tern reveals that the product is single phase of CO9S8 Transmission electro
n microscopy shows that the average particle size of Co9S8 is about 20 nm.
The possible mechanism for the formation of Co9S8 and the influence of expe
rimental conditions are discussed. (C) 1999 Elsevier Science Ltd. All right
s reserved.