Electro-responsive and dielectric characteristics of graphene sheets decorated with TiO2 nanorods

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%).