Single-step Synthesis of Molybdenum Carbide Nanoparticles by Wire Explosion Process

Abstract

We propose the synthesis of MoC1-x nanoparticles (NPs) with Mo wire as starting material and to carryout explosion in the methane gas medium, which acts as carburizing medium, as well as a coolant, to bring down the local temperature rise to a value lower than the melting point of the material. To control the phase and morphology of NPs, two parameters are defined in wire explosion process (WEP): energy ratio, K (ratio of energy supplied to wire and sublimation energy of wire) and pressure, P of ambient gas. XRD, TEM, SEM and XPS were used to characterize the synthesized NPs. Pure Moc1-x was synthesized for K = 5.8 and P = 170 kPa. Carburization is more for high K/P. For low pressure case, one has to provide more K to get complete carburization. XPS confirms the formation of MoC without any oxidation of Mo vapour. Spherical NPs were obtained with least mean particle size of 20 nm. Particle size decreases with increase in K and/or decrease in P.