Self-assembled free-standing graphene oxide hybrid films modified by silane functionalized TiO2 nanotubes to increase their final Young's modulus

Abstract

Free-standing hybrid films of graphene oxide (GO) and titanium dioxide nanotubes (TNT) were prepared trough a bar coating and drying method from GO-based dispersions. Successful chemical functionalization of the nanotubes with allyltriethoxysilane as a linker is confirmed by XPS and Raman spectroscopy. These resulting functionalized nanotubes were then used to prepare self-assembled hybrid films with GO in aqueous suspension. These hybrid films exhibit outstanding mechanical properties. The Young's modulus was as high as ∼10 GPa (38% higher than the pristine graphene oxide film) and an ultimate tensile strength around ∼40 MPa. The method presented here is versatile, and it can be easily coupled to fabricate other graphene-based hybrid films for applications, such as fuel-cells, photocatalysis, filters, amongst others.