Fabrication and characterization of carbon doped molybdenum oxide nanostructures

Molybdenum oxide (MoOx) nanostructure has gained considerable attention because of its low-cost fabrication by low-temperature evaporation/condensation technique and its promising properties for applications in the field of catalysts and chemical sensors. However, MoOx has some inferior properties including very high electrical resistivity and instability at elevated temperature. These properties may be improved by means of foreign atom addition into its nanostructure. In this work, we develop a simple mean for doping of MoOx nanostructures by introduction of gas source dopant during evaporation. Carbon doped MoOx nanostructures have been synthesized by MoOx powder evaporation in Argon/Acetylene mixture with varying process parameters. Depending on growth conditions, various nanostructures including, nanorod, nanoplate, nanodots, can be formed with different dimensions and doping concentrations. Structural characterization by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD) indicate that the MoOx based nanostructures are highly crystalline and carbon dopant is successfully incorporated in the structure with controllable concentration. Electrical characterization shows that the electrical conductivity of molybdenum oxide nanostructures can be increased by several orders of magnitude with carbon incorporation.