Obtaining hybrid nanostructures based on graphene and nano-ZrO2

A technologically promising method for obtaining nanostructured graphene/ZrO2 has been proposed. Its main idea is to use suspensions of graphene and nano-ZrO2 and create conditions for the interaction of graphene sheets and ZrO2 crystallites to form a hybrid nanostructured powder without the formation of new chemical bonds. The oxygen-free graphene sheets with thickness of several nanometers were obtained by sonochemical method in N,N-dimethyloctylamine-aqua emulsion. Nano-ZrO2 powder with average crystallite size of 8.1 nm was synthesized by sol-gel method. The morphology and phase composition of all synthesized objects (nano-ZrO2, graphene, composite) were studied by using a set of instrumental methods (transmission electron microscopy (TEM) and electron diffraction, x-ray diffraction (XRD), electron energy loss spectroscopy (EELS), nitrogen adsorption-desorption, diffusion aerosol spectrometry (DAS) and elemental analysis). It was shown that the proposed method allows obtain chemically homogeneous mesoporous hybrid powders consisting of graphene sheets and ZrO2 crystallites with a size of 8 – 13 nm fixed on them. We investigated an effect of duration of ultrasonic impact to graphite on the morphology of the hybrid and the mechanism of its formation. According to the results of a comprehensive analysis of the obtained data, the mechanisms for the formation of graphene suspension in emulsion and a nanostructured hybrid during the interaction of crystalline ZrO2 and oxygen-free graphene sheets in an aqueous-organic medium was proposed. The developed hybrid nanostructures are highly demanded innovative raw-products in the production of (photo)catalysts for a wide range of processes, sensor, ceramic and electrical materials, and materials for medical and biological purposes.