Jul 12, 2012
Carbon nanotubes grown on graphene quantum dot assembly
Graphene quantum dots (GQDs), which consist of single- or few-layer graphene with a tiny size of only several nanometres, represent a new type of quantum dot (QD) with the properties of both graphene and quantum dots. This could open the door to new devices with extraordinary functions. The assembly of regular QDs in a geometrically well defined fashion provides opportunities to control optical and electronic coupling between the individual QD units and form structures with collective properties. However, the self-assembly of GQDs has been less well developed. Now, a team of scientists from Beijing Institute of Technology (BIT) and Beijing Normal University (BNU) has helped to advance the field by successfully preparing an assembly of GQDs using a water-in-oil (W/O) emulsion technique without the addition of any surfactants.
The as-formed GQD microspheres are solid and remain intact after slight ultrasonication. The versatile W/O emulsion method allows the in situ intercalation of functional nanocomponents into the GQD microspheres for specific applications. One example reported in the work is a sample of Fe3O4–containing GQD microspheres, which exhibits a great magnetic response.
Furthermore, the embedded Fe3O4 nanoparticles in GQD microspheres can act as catalysts for the growth of carbon nanotubes (CNTs), which highlights opportunities for fabricating new hierarchically complex structures comprising CNTs surrounding GQD microspheres by simple chemical vapour deposition.
More details can be found in the journal Nanotechnology.
About the author
The study was conducted by research teams from BIT and BNU in Beijing, China. Yi Ding is a Masters student in chemistry at BIT. He performed the controlled assembly of GQDs and characterization of the material. Prof. Liangti Qu is head of the functional nanostructure chemistry group at BIT. His research focuses mainly on nanochemistry, advanced functional materials and devices. Topics include the controlled synthesis of new functional nanomaterials, as well as assembly processes and applications in various areas.