Nanoarchitectonics of mesoporous carbon from C60/PCBM hybrid crystals for supercapacitor

Abstract

Owning a highly symmetric geometry, fullerenes are popular building blocks in nanoarchitectonics. The successful preparation of fullerene superstructures with various sizes and dimensions forms the basis for their applications. However, the lack of porosity and the limited electrical conductivity of most fullerene superstructures prevent their applications in energy-related fields such as supercapacitors. Herein, hybrid crystals with a crossed-tubular morphology and a hexagonal close packed (hcp) lattice were constructed by fullerene C60 and its derivative, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), through a modified liquid-liquid interfacial precipitation method. Subsequent calcination can greatly improve the porosity of this hybrid crystals and produce mesoporous carbon with an increased BET surface area nearly 30 times (from 13.91 to 432.41 m2 g−1), which exhibited a good performance as an electrode material in supercapacitor with a capacitance retention rate of 87.3% after 2000 cycles and specific capacitances of ∼213 F g−1 at 5 mV s−1 and ∼158 F g−1 at 1 A g−1, respectively. Compared to the crystals formed solely by fullerenes, the presence of PCBM lowered the calcination temperature and induced self-doping of oxygen. In addition, rough surfaces could be produced on the superstructures by solvent etching, which increased as well the performance of the material in supercapacitor. Our work provided a new strategy to engineer fullerene-derived functional materials for applications in energy storage and expanded the knowledge on the factors regulating their performance when using as electrode materials in supercapacitors.