AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Development of Crumpled Graphene-based Nanocomposites via Aerosol Route for Environmental Applications
WEI-NING WANG, Yi Jiang, John Fortner, Pratim Biswas, Washington University in St. Louis
Abstract Number: 145 Working Group: Nanoparticles and Materials Synthesis
Abstract A possible solution to solve the restacking issue of graphene oxide (GO) nanosheets during large-scale production is to turn the 2D nanosheets into 3D crumpled balls that have excellent compressive properties but still maintain high free volumes. An aerosol-based process has been proven to be a rational method for this purpose, in which, the crumpling phenomenon, however, has hitherto remained unclear. In this work we present a detailed understanding of the crumpling of GO nanosheets by a systematic investigation conducted in aerosolized droplets by means of in-line (e.g., scanning mobility particle sizer) and off-line (e.g., electron microscopy) measurements. Correlations between the confinement force and various parameters, such as evaporation rate and precursor concentration were established to derive a universally applicable equation.
In addition, the synthesis of ternary crumpled graphene-TiO2-magnetite nanocomposites via aerosol route was also demonstrated in this work. The as-synthesized core-shell nanostructured photocatalyst, with controllable size and functionality, exhibited enhanced photocatalytic activity compared to bare TiO2; and is readily to be magnetically collected and redispersed in water. Compared with bare TiO2, crumpled graphene-TiO2 could increase lifetime of photo-induced holes and electrons by significantly reducing their recombination. By employing various hole and radical scavengers, we proposed the main reaction pathways for photo-induced holes and electrons, and based on which we demonstrated the shifting of oxidation pathway toward reduction one. This study provides new insights into synthesizing ternary crumpled graphene-based multifunctional nanocomposites for various environmental applications.