Electro-responsive and dielectric characteristics of graphene sheets decorated with TiO2nanorods

Abstract

Titanium dioxide (TiO₂) nanorod-decorated graphene sheets have been synthesized by a simple non-hydrolytic sol–gel approach and demonstrated to be a highly effective dispersing material for electrorheological fluids. Electron microscopy and X-ray diffraction analysis indicated that the TiO₂ nanorods with a high crystallinity are well-dispersed and successfully anchored on the graphene sheet surface through the formation of covalent bonds between Ti and C atoms. Furthermore, electro-responsive properties of graphene sheets decorated with TiO₂ nanorods are investigated on the basis of the dielectric loss model. The dielectric property analysis based on the dielectric loss model clarifies that an introduction of TiO₂ nanorods has been coupled with the larger achievable polarizability and short relaxation time of interfacial polarization. Consequently, the TiO₂ nanorod-decorated graphene sheets exhibit consistently higher ER efficiency than that of GO sheets and show unprecedented electro-responsive performance in extremely low concentration ER materials (<0.2 wt%).