Efficient Synthesis of Nitrogen-Doped Porous Carbon Nanosheets for High-Performance Supercapacitors

Abstract

Developing electrode materials with more active sites through simple preparation methods is crucial for enhancing the electrochemical performance of supercapacitors (SC). Herein, a nitrogen doped porous carbon nanosheet (NPCS) was successfully synthesized via one-step self-sacrificial template method. The mass ratio of g-C3N4 template/phenolic resin prepolymer is a key factor regulating the microstructure of NPCS. The optimized NPCS-3 has a high specific surface area (880 m2·g-1), rich mesoporous structure, appropriate nitrogen content (2.35 %), and uniform sheet-like morphology. Based on the unique structural merits, the NPCS-3 displays a high specific capacitance of 355 F·g-1 at 0.5·A g-1, a good rate capability with an 80.6 % retention, and outstanding cycling stability with a 92.1 % capacitance retention after 10000 cycles. The NPCS-3//NPCS-3 symmetric SC also achieves a high energy density of 18.6 W h·kg-1 and power density of 11.0 kW·kg-1. The simple and scalable self-template strategy provides a new direction for the synthesis of high-performance 2D carbon nanomaterials for electrochemical energy storage applications.

Keywords: Heteroatom doping, Porous carbon, 2D nanosheets, Self-sacrificial template, Supercapacitor