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.

Catalyst cores

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.