Macroporous Graphene Frameworks for Sensing and Supercapacitor Applications

摘要

3D architectures based on graphene have triggered a great deal of interestin energy, sensing, and environmental applications. This work describes, asimple electrochemical approach for the direct deposition of a functionalizedgraphene framework by utilizing electrostatic interactions betweengraphene oxide (GO) and a cationic surfactant. The surfactant improves theadsorption of GO sheets on the electrode surface, allowing the integrationof individual graphene sheets into 3D structures with large electrochemicallyactive surface area. Without using binders or conductive additives,the current approach leads to supercapacitors with high specific capacitance(320 F g~(?1)) and areal capacitance (≈400 mF cm~(?2) for two electrodecells with single-sided coatings), which compares favorably to commercialactivated carbon supercapacitors. Moreover, the supercapacitors demonstratelow internal resistance (≈1 Ω cm~(?2)), excellent cycling stability (no lossobserved after 10 000 cycles) while also maintaining superior rate capability.In another application, these frameworks were successfully implementedas an electrochemical sensor for the simultaneous determination of smallbiomolecules including ascorbic acid, dopamine and uric acid with high sensitivity,selectivity and reproducibility. This work provides a simple, yet effective,strategy for the fabrication of macroporous electrodes with superiorchemical, structural, and electrical properties that are desirable for a broadrange of applications.