Molybdenum disulfide nanowires and nanoribbons by electrochemical/chemical synthesis.

Molybdenum disulfide nanowires and nanoribbons have been synthesized by a two-step, electrochemical/chemical synthetic method. In the first step, MoOx wires (a mixture of MoO2 and MoO3) were electrodeposited size-selectively by electrochemical step-edge decoration on a highly oriented pyrolytic graphite (HOPG) surface. Then, MoOx precursor wires were converted to MoS2 by exposure to H2S either at 500−700°C, producing “low-temperature” or LT MoS2 nanowires that were predominantly 2H phase, or above 800°C producing “high-temperature” or HT MoS2 ribbons that were predominantly 3R phase. The majority of these MoS2 wires and ribbons were more than 50 μm in length and were organized into parallel arrays containing hundreds of wires or ribbons. MoS2 nanostructures were characterized by X-ray photoelectron spectroscopy, scanning and transmission electron microscopy, selected area electron diffraction, X-ray diffraction, UV−visible absorption spectrometry, and Raman spectroscopy. HT and LT MoS2 nanowires were stru...