Construction and regulation of molybdenum carbide/carbon hollow microtube composite and its supercapacitive behaviors

Crystal structure has an important effect on electrochemical performance. In this work, the molybdenum carbide/carbon hollow microtube (MoC/CHMT) composite is synthesized via carbonation of polydopamine encapsuled Mo-MOF material. Additionally, the crystal structure of molybdenum carbide in composite is controlled by adjusting the mass of dopamine in polymerization. The optimized MoC/CHMT shows the hollow microtubes morphology with the microtube diameter about 600~1100 nm and microtube wall thickness of 230~400 nm, constructed by small molybdenum carbide nanoparticles (about 1.2~1.5 nm) on the surface of nanoplates with thickness of ~17 nm. Moreover, it could achieve a high specific capacitance of 513.5 F g-1 at a current density of 0.5 A g-1. The constructed YP50//MoC/CHMT device exhibits a maximum energy density of 17.5 Wh kg-1.