Nitrogen‐Doped Porous Graphene‐Based Aerogels toward Efficient Heavy Metal Ion Adsorption and Supercapacitor Applications

Abstract

Graphene‐based aerogels with different chitosan contents are selectively prepared by the hydrothermal reaction. It is found that with increasing chitosan content, the density of graphene‐based aerogels decreases and their specific surface area enhances gradually. With the optimized mass ratio of chitosan to graphene oxide (4:1), its density and specific surface area are 11.0 mg cm −3 and 616 m 2 g −1 , respectively. Due to the well‐dispersed functional groups grafted on graphene and strong coordination ability to heavy metal ions, its saturated adsorption capacities for Cu 2+ and Pb 2+ are as high as 342.4 and 945.1 mg g −1 , respectively. After carbonization at 900 °C, the nitrogen element is incorporated into the skeleton of aerogels, and the resulting nitrogen‐doped graphene‐based aerogels show excellent electrochemical performance in supercapacitor applications. The present method paves the way for the synthesis of heteroatom‐doped graphene‐based aerogels for multifunctional special applications.