Multi-layered zeolitic imidazolate framework based self-templated synthesis of nitrogen-doped hollow porous carbon dodecahedrons as robust substrates for supercapacitors

Abstract

Many reported synthetic methods for hollow porous carbon dodecahedrons based on a templating strategy are relatively complex, and the obtained hollow structure is usually single shell. Herein, we propose a multi-layered zeolitic imidazolate framework based self-templated synthesis of nitrogen-doped hollow porous carbon dodecahedrons with various architectures such as single-shell, double-shell, yolk–shell and yolk-double-shell. The mechanism of formation of the hollow structure is also demonstrated and it indicates that our strategy can be extended to prepare more multi-shell or yolk-multi-shell nitrogen-doped hollow porous carbon dodecahedrons. All obtained nitrogen-doped hollow porous carbon dodecahedrons are employed as electroactive materials for the construction of supercapacitor electrodes. Owing to their hierarchical micro/mesoporous structure, high nitrogen doping, large surface area, graphitic structure, and the unique yolk-double-shell hollow structure, nitrogen-doped yolk-double-shell hollow porous carbon dodecahedrons (N-YDS-HPCDs) exhibit a distinguished capacitance of 346 F g⁻¹ at a current density of 0.5 A g⁻¹, excellent stability with approximately 93% capacitance retention after 10 000 cycles, and a high energy density of 11.64 W h kg⁻¹ at a power density of 250 W kg⁻¹.