Due to its extraordinary properties including structural simplicity and stability, electrochemical activity, large specific surface area, high electrical and thermal conductivity, and ease of functionalization, graphene offers a new opportunity to boost the performance of carbon-based sensors and energy storge devices. The specific capacitance of graphene and graphene-based composites is very sensitive to the processing parameters as well as the material structure at the nanoscale. We have recently designed, fabricated, and characterized a number of graphene-based nanostructured carbon composites as electrochemical electrodes. In this work, graphene and single-walled carbon nanotube composite aerogel and several different nanostructured metal oxides deposited on graphene nano-sheets have been fabricated for selective detection of biomolecules of asuric acid, dopamine, and glucose. In the composite sensors, graphene promotes electron transfer reactions and enhances the electrical signals drastically for biomolecular detection, which is attributed to the special nano-sheet structure and high electrical conductivity. We also will describe the processing of graphene and graphene-based materials aimed at obtaining higher specific capacitance. The nanoscopic structure of the high performance electrode material is analyzed using high-resolution electron microscopy, electron tomography, x-ray diffraction, and Raman spectroscopy. Electrochemical characterization of the graphene composites, which show high energy density in energy storage, will also be presented. 

Due to its extraordinary properties including structural simplicity and stability, electrochemical activity, large specific surface area, high electrical and thermal conductivity, and ease of functionalization, graphene offers a new opportunity to boost the performance of carbon-based sensors and energy storge devices. The specific capacitance of graphene and graphene-based composites is very sensitive to the processing parameters as well as the material structure at the nanoscale. We have recently designed, fabricated, and characterized a number of graphene-based nanostructured carbon composites as electrochemical electrodes. In this work, graphene and single-walled carbon nanotube composite aerogel and several different nanostructured metal oxides deposited on graphene nano-sheets have been fabricated for selective detection of biomolecules of asuric acid, dopamine, and glucose. In the composite sensors, graphene promotes electron transfer reactions and enhances the electrical signals drastically for biomolecular detection, which is attributed to the special nano-sheet structure and high electrical conductivity. We also will describe the processing of graphene and graphene-based materials aimed at obtaining higher specific capacitance. The nanoscopic structure of the high performance electrode material is analyzed using high-resolution electron microscopy, electron tomography, x-ray diffraction, and Raman spectroscopy. Electrochemical characterization of the graphene composites, which show high energy density in energy storage, will also be presented.