Hybrid Structure of Zinc Oxide Nanorods and Three Dimensional Graphene Foam for Supercapacitor and Electrochemical Sensor

12/marzo/2011
Maximiliano De La Higuera Macías

A hybrid structure of zinc oxide (ZnO) on three dimensional (3D) graphene foam has been synthesized by chemical vapor deposition (CVD) growth of graphene followed by a facial in-situ precipitation of ZnO nanorods under hydrothermal conditions. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used to characterize the morphology and structure of graphene/ZnO hybrids. The results show that the ZnO nanorods have high crystallinity and cluster uniformly on graphene skeleton to form flower-like nanostructures. Serving as a free-standing electrode, the electrochemical and biosensing performance of graphene/ZnO hybrid are studied by cyclic voltammetry, electrochemical impedance spectroscopy, galvanostatic charge/discharge and amperometric measurements.

It is found that the graphene/ZnO hybrids display superior capacitive performance with high specific capacitance (~400 F/g) as well as excellent cycle life, making them suitable for high-performance energy storage applications. Furthermore, the graphene/ZnO hybrids exhibit a high sensitivity for detection of [Fe(CN)6]3+ and dopamine, with the extropolated lower detection limits of ~1.0 µM and ~10.0 nM respectively. These results demonstrate the potentials of free-standing graphene/ZnO hybrid electrode for the development of highly sensitive electrochemical sensors.

Peng Chen. Hybrid Structure of Zinc Oxide Nanorods and Three Dimensional Graphene Foam for Supercapacitor and Electrochemical Sensor Applications. RSC Advances. Royal Society of Chemistry. Mar 2, 2012. http://pubs.rsc.org/en/content/articlepdf/2012/ra/c2ra01295b