Synthesis of molybdenum carbide using mechanochemical and thermal approaches

Abstract

The carbothermic reduction of  MoS₂ using Mg, an efficient sulfur scavenger, was carried out by two very different routes, i.e., mechanochemical reaction and heat treatment. The thermodynamic calculation results show that Mo₂C and MgS are the phases formed when the elements are combined, and carbothermic reduction of molybdenite takes place. XRD analysis data indicates no reaction occurred at 1, 2, and 5 h of milling by the mechanochemical method, and the initial phases MoS₂, Mg, and C were identified. On the other hand, after 7 hours of milling, Mo₂C and MgS phases finally emerged. Through heat treatment, the desired Mo₂C and MgS phases were successfully prepared with the crystal diffraction spots obvious at 700, 800, and 900 °C, respectively. Both of these methods produced powders which were then washed with a 10% 1M HCl solution, and as a result, a reasonable yield of pure molybdenum carbide was obtained.