3D-printed graphene-Al2O3 composites with complex mesoscale architecture

Composites of reduced graphene oxide (rGO) and Al2O3 with complex three-dimensional (3D) mesoscale architecture were prepared by a combination of 3D printing technique and thermal reduction process. For this purpose, stable aqueous graphene oxide (GO) suspensions were prepared using GO sheets synthesized previously from graphite powders according to a modified Hummers method. The printability of the resulted inks was investigated by rheological tests under steady and dynamic shear conditions. GO-Al2O3 structures with a 3D interconnected network were fabricated and thermally reduced in an N-2 atmosphere. Finally, the reduction and distribution, as well as the integrity of rGO sheets in the ceramic matrix were evaluated using scanning electron microscopy (SEM), Raman spectroscopy, and X-ray diffraction (XRD) analysis. The reported 3D printed rGO-Al2O3 composite offers a strategy for the fabrication of other graphene-ceramic composites with a high geometric surface area for a broad range of technological applications.