Amine-enriched Graphene Quantum Dots for High-pseudocapacitance Supercapacitors

• Published in: Electrochimica acta Vol. 208; pp. 260 - 266
• Main Authors: Li, Zhen, Qin, Ping, Wang, Liang, Yang, Chengshuai, Li, Yanfeng, Chen, Zhiwen, Pan, Dengyu, Wu, Minghong
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2016
• Subjects: amine-functionalization; Arrays; Capacitance; Carbon; Graphene; graphene quantum dots; Nanostructure; pseudocapacitance; Quantum dots; Supercapacitors; Titanium dioxide; amine-functionalization; pseudocapacitance; graphene quantum dots; supercapacitors
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2016.05.030

[Display omitted] •Amine-enriched porous carbon electrodes have been fabricated by the electrostatic fusion of amine-functionalized single-crystalline GQDs.•The carbon films deliver ultrahigh specific capacitance (400–595Fg−1) by inducing a high concentration of active amine moieties at edge.•GQD supercapacitors offer energy density up to 21.8Whkg−1 and retain 90% of the initial capacitance after 10,000 cyclic voltammetry tests.•Amine-enriched GQDs can function as a highly active, solution-processable pseudocapacitive materials applicable to high-performance supercapacitors. The applications of carbon-based supercapacitors have been limited by their low energy storage density owing to their limited active storage sites. To overcome this limitation, amine-enriched porous carbon electrodes have been fabricated by the electrostatic fusion of amine-functionalized single-crystalline graphene quantum dots (GQDs) within conductive, vertically ordered TiO2 nanotube arrays as the collectors. The carbon films deliver ultrahigh specific capacitance (400–595Fg−1) even beyond the theoretical upper limit of single-layer graphene by inducing a high concentration of active amine moieties at edge. Symmetrical GQD supercapacitors in H2SO4 electrolyte offer energy density up to 21.8Whkg−1 and retain 90% of the initial capacitance after 10000 cyclic voltammetry tests. The results show that amine-enriched GQDs can function as a new kind of highly active, solution-processable, and low-cost pseudocapacitive materials applicable to high-performance supercapacitors.