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.