Porous nanotubes derived from a metal-organic framework as high-performance supercapacitor electrodes

In this work, porous Co₃O₄ nanotubes were prepared by calcining nanoscale Co-MOF-74 crystals at an optimized temperature. The shell of the Co₃O₄ nanotubes consisted of small interconnected nanoparticles. Supercapacitors were successfully constructed using the resulting porous Co₃O₄ nanotubes as electrode materials. Electrochemical data demonstrated that the Co₃O₄ nanotubes exhibited good capacitive behavior with a specific capacitance of 647 F g⁻¹ at a current density of 1 A g⁻¹. Apart from high capacitance, the Co₃O₄ nanotubes also demonstrated excellent cycling stability with no obvious decrease after 1500 cycles at 2 A g⁻¹, which indicated that it can be promising electroactive materials for supercapacitors. The remarkable performance of the nanotubes could be attributed to their special morphology and appropriate pore-size distribution.