Preparation of N-doped porous carbons via high internal phase emulsion template

Abstract

Heteroatom doped porous carbon materials have great application prospects in supercapacitors. In the present study, an approach of preparing N-doped porous carbon (NPC) was proposed from porous poly(resorcinol-formaldehyde-melamine) monoliths which were prepared by high internal phase emulsion (HIPE) template. Melamine was dissolved in the external phase and copolymerized, acting as the N source and porous structure regulator to provide micropore-dominant NPCs. The structure, morphology, specific surface area (SSA), and chemical composition of the samples were systematically studied. With melamine content increasing, N-doping content in NPC increased while the SSA of NPC increased at first and then decreased. When the content of N is 8.42 ​wt%, the obtained NPC showed the highest SSA of about 1670 ​m2 ​g−1. Furthermore, high N doping content could improve the electronic conductivity and provide additional pseudocapacitance of NPC. Under the combined influences of proper N content and high porosity, the prepared NPC electrodes revealed excellent specific capacitance (228.0 ​F ​g−1 at 1.0 ​A ​g−1), favorable circling stability, and prominent rate capability in a three-electrode system with 6 ​M KOH solution as the electrolyte.