Poly(ionic liquid)/carboxymethyl chitosan complex-derived nitrogen and sulfur codoped porous carbon for high-performance supercapacitors

Abstract

In this study, nitrogen- and sulfur-codoped porous carbon (NSPC) was prepared via the direct carbonization of an electrostatically cross-linked complex of hydrophobic poly(ionic liquid) (PIL) and carboxymethyl chitosan (CMC). Our results demonstrate that an intact carbon membrane featured with substantial micropores can be achieved facilely through the newly developed technique. NSPCs are characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nitrogen adsorption–desorption analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy. NSPC pyrolyzed at 1000 °C (NSPC-1000) offers a specific surface area as high as 1520 m2 g−1. Importantly, the electrode fabricated with NSPC-1000 can provide a specific capacity as high as 633 F g−1 at the current density of 0.1 A g−1 in 1.0 M H2SO4 and excellent cycle stability without obvious capacity loss after 10,000 cycles. Our studies thus propose a novel strategy to fabricate porous carbon membrane with high electrochemical performance using PIL and biomacromolecules.