N-doped hollow carbon nanoplates with mesoporous thin shells towards high-performance supercapacitors

Abstract

Integrating hollow structures and ordered mesopores in carbon materials is critical for electrochemical devices to facilitate fast ion-transport pathways and large ion-accessible surface areas. In this work, a self-templating method is used to prepare hollow ordered mesoporous carbon (HOMC) materials by self-assembling resol-F127 composite micelles on the surface of two-dimensional (2D) metal-organic-framework (MOF) nanoplates, followed by polymerization and carbonization. During the hydrothermal reaction, MOF nanoplates act as a 2D template to assemble resol-F127 composite micelles, leading to hollow ordered mesostructured polymer (HOMP). At the same time, N-containing species are released from the dissolved MOF nanoplates, resulting in N-doped HOMC after carbonization. Benefiting from the structural advantages (e.g., high surface area, hierarchical porous architecture composed of hollow interiors and thin mesoporous shells) and the high amount of N-doping, the as-prepared HOMC exhibits superior electrochemical performance for supercapacitors, demonstrated by a high specific capacitance of 271 F g−1 at a current density of 0.5 A g−1, excellent rate capability, and high capacitance retention of 98.1% after 20,000 cycles. The strategy can provide a new avenue for designing and constructing hollow carbon materials for various applications in electrochemical energy storage devices.