Nitrogen-doped hollow carbon polyhedron derived from metal-organic frameworks for supercapacitors

Abstract

Metal-organic frameworks (MOFs) derived carbon materials have great potential to be utilized as electrode materials in the field of energy storage and conversion. In the present work, nitrogen-doped hollow carbon polyhedron and hollow carbon sphere are synthesized using MOFs coated with carboxylated polystyrene (PS) microspheres as precursors. The morphology evolution of the hollow carbon has been discussed, which are subject to the reactant concentration and solvothermal temperature. The as-prepared hollow carbon has superior electrochemical performances for supercapacitors, owning to the hollow structure, high specific areas and nitrogen doping. The discharge specific capacitances of the hollow carbon polyhedron and hollow carbon sphere are respectively 160.2 F/g and 186.4 F/g under 0.2 A/g current density. Furthermore, the capacitance retentions of the hollow carbon polyhedron and hollow carbon sphere are 96.4 % and 98.9 % after 10,000 cycles, presenting excellent cycling stability. This work could provide new insight into the controllable design and synthesis of hollow carbon materials for energy storage.