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 similar to 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).

Automated summary

The crystal structure has a significant impact on the electrochemical performance. In this study, the molybdenum carbide/carbon hollow microtube (MoC/CHMT) composite was synthesized by carbonating polydopamine-encapsulated Mo-MOF material. The crystal structure of molybdenum carbide in the composite was controlled by adjusting the mass of dopamine during polymerization. The optimized MoC/CHMT exhibited hollow microtubes morphology with small molybdenum carbide nanoparticles on the surface, and it achieved a high specific capacitance of 513.5 F g(-1) at a current density of 0.5 A g(-1). The YP50//MoC/CHMT device showed a maximum energy density of 17.5 Wh kg(-1).