Chitin derived nitrogen-doped porous carbons with ultrahigh specific surface area and tailored hierarchical porosity for high performance supercapacitors

Abstract

In this study, we report the fabrication of nitrogen rich activated nanosized carbon with hierarchical micro/mesoporous and ultrahigh specific surface area by template-free and one-step carbonization-activation method, which greatly simplified the process and avoided the waste of reagents. Chitin nanoparticles were prepared by a mechanical induced sol-gel transition process in NaOH/Urea solvent and a subsequent carbonization utilizing NaOH for activation and urea for N doping, resulting in activated carbon (ACNC-800) with extraordinary specific surface area (2631 m2/g) and high nitrogen content (7.1%). Further characterization and electrochemical tests demonstrate high electrochemical performance of the activated nanocarbon. Under the current density of 0.5 A/g, the specific capacitance of the three-electrode system is 245 F/g and that of the two-electrode system is 227 F/g. The assembled capacitors exhibit superior rate performance and good cycle stability (98% capacitance retention after 10000 charge-discharge cycles). This work introduces a simple and efficient strategy to prepare N-doped carbon with hierarchical porosity applied to high performance supercapacitors.