Vacuum synthesis of molybdenum disulfide (MoS2) using molybdenum trioxide (MoO3) and sulfur powder is presented in this study based on the equilibrium phase diagram of MoO3-S and MoO2-S at 10 Pa. The phase transitions and controlled sulfurization during the process of MoO3 to MoS2 were carried out in the temperature range from 673 to 1073 K, and 2H-MoS2 were obtained by controlling the addition of sulfur powder. It was found that MoO2 is the only detectable intermediate phase via the reactions of sulfur with MoO3 from 673 to 973 K. The experimental findings confirmed that the sulfurization of MoO3 to MoS2 was a consecutive reaction with the intermediate product MoO2, which could be demonstrated by the results of X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). With the increases in temperature were promoted the conversion of MoO2 to MoS2, and MoS2 was formed at 1073 K with average lateral dimensions of similar to 1.30 mu m. The formation of MoS2 in vacuum was found to obey the chemical vapor transport (CVT) mechanism under the experimental condition, as the phase transition of "MoO3 -> MoO2 -> MoS2" was confirmed and the morphology evolutions were given in this work.
展开▼
