Room temperature synthesis of metal chalcogenides in ethylenediamine

Reaction of sulfur and selenium with elemental or ionic metals in liquid ethylenediamine at room temperature produced metal chalcogenides ME (M = Cu, Sn, Co2+, Ni2+, Mn2+, or Pb2+; E = S or Se), Ag2E, M2E3 (M = Bi or Sb). The results showed that the products had a range of crystalline sizes from 10 to 100 nm. Some reactions produced molecular precursors. Heat treatment of these precursors at 250 degrees C under a N-2 atmosphere induced crystalline chalcogenides. The pre- and postheated metal chalcogenides were analyzed by X-ray diffraction (XRD). Some key compounds are analyzed by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The roles of ethylenediamine in the reaction system are also discussed in this report.