Synthesis of Boron and Nitrogen Codoped Porous Carbon\nFoam for High Performance Supercapacitors

Abstract

A facile\nand efficient method to prepare boron and nitrogen codoped\nporous carbon foam (BNPC) derived from starch with urea as nitrogen\nsource and boric acid as both boron source and templet is presented.\nThe codoping strategy can boost the synergistically doping amounts\nof boron and nitrogen, which can achieve a great increase in the doping\nefficiency of boron (three times higher than single boron doping)\nand nitrogen. Due to its hierarchical pore structure with moderate\nspecific surface and relatively high nitrogen (9.38 at. %) and boron\n(3.87 at. %), the BNPC electrode exhibits outstanding electrochemical\nperformances with an ultrahigh specific capacity of 402 F g^–1 at a current density of 0.5 A g^–1 and retains\n266 F g^–1 even at a current density of 20 A g^–1 in 6 M KOH electrolyte. In addition, a symmetric\ndevice based on BNPC electrodes delivers a respectable energy density\nof 21.9 Wh kg^–1 in 1 M Na₂SO₄ electrolyte. Therefore, this work provides a simple and efficient\nmethod to synthesize heteroatom-doped hierarchical porous carbon materials\nfor advanced energy storage systems.