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℃, 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 10,000 cycles).