Zif-8-Templated Synthesis of Core-Shell Structured Ipop@Mof Hybrid-Derived Nitrogen-Doped Porous Carbon for Efficient Oxygen Reduction Electrocatalysis and Supercapacitor

Abstract

Nitrogen-doped porous carbon materials based on porous organic polymers and metal-organic framework derivatives are prepared for efficient ORR electrocatalysts and supercapacitor. The classic MOFs material ZIF-8 is selected as the core material. After ZIF-8 is pyrolyzed in an inert atmosphere at 900°C, the low-boiling Zn volatilizes, resulting in a hierarchical open-structured carbon-nitrogen material, which is beneficial to the transport of electrolytes in the electrocatalytic process. To further increase the nitrogen content, the designed nitrogen-rich IPOP-coated ZIF-8 composites were immersed in an aqueous solution of sodium dicyandiamide. The catalyst obtained by replacing Cl- and Br- in the porous organic polymer with nitrogen-containing ions and calcined at high temperature is a porous structure material containing a high concentration of active pyridine nitrogen. In addition to exhibiting superior oxygen reduction reaction (ORR) electrocatalytic activity, NC-900 shows superior stability and good methanol tolerance in comparison to commercial Pt/C catalysts in alkaline media as well as acidic media. Furthermore, in 6 M KOH electrolyte, NPCs-based supercapacitor exhibits a high capacitance of 225 F g-1 with a current density of 1 A g-1 and possesses good cycling stability (95.75% capacitor retention after 10000 cycles).

Keywords: porous organic polymers, Metal-Organic Frameworks, Oxygen reduction reaction, Supercapacitor