High-performance supercapacitor based on nitrogen-doped porous carbon derived from zinc(II)-bis(8-hydroxyquinoline) coordination polymer

Nitrogen-doped porous carbon electrodes with remarkable specific capacitance have been fabricated by the rational carbonization of zinc(II)-bis(8-hydroxyquinoline) (abbr. Znq2) coordination polymer, and heating treatment with CO(NH2)2. The experimental results demonstrate that the mass ratio of carbon precursor and CO(NH2)2 plays a key role in the formation of porous carbon with various nitrogen content as well as specific surface areas and pore structures. The cyclic voltammetry and galvanostatic charge–discharge measurements show that the capacitive performance has been remarkably improved by doping with nitrogen. The specific capacitance of 219.2 F g−1 is achieved at the current density of 1 A g−1 with nitrogen-doped porous carbon, increasing up to ca. 56.8% compared to that with pristine porous carbon. The nitrogen-doped porous carbon electrode exhibits enhance capacitance retention as ca. 45.2% at 20 A g−1 as well as cycling stability (ca. 7.6% loss after 3000 cycles). The present carbonization method as well as the nitrogen-doping method for porous carbon from coordination polymer can enrich the strategies for the production of carbon-based electrodes materials in the application of electrochemical capacitors.

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► A simple carbonization method was developed to prepare porous carbon.
► The precursor of Znq2 derives from coordination polymer.
► The doping processes for nitrogen/boron are simple and reproducible.
► Doping nitrogen into carbons can greatly improve capacitive performances.