Synthesis of Graphene-CeO₂ Nanocomposite Using Dodecylamine

A method is proposed for the synthesis of nanostructured composites based on graphene and CeO2, which combines sol-gel and sonochemical methods. A feature of the method is that, when the graphene content is not more than 2 wt %, its uniform distribution in the volume of the material is achieved without the formation of an impurity phase. In addition, oxygen-free graphene with a sheet thickness of 3-5 nm is used in the synthesis as a suspension obtained by ultrasonic exfoliation in an alkalized by KOH water-alcohol solution of dodecylamine. The formation of a composite in a mixed colloid occurs in such a way that the sol-gel transition and subsequent crystallization of nano-CeO2 occur on the graphene sheets. However, chemical interaction of the latter and CeO2 in the composite is not observed, which contributes to the preservation of the sp(2) electron system of graphene and, as a result, the preservation of its unique electronic properties. The graphene sheets form a layered structure of composite agglomerates, and isolated CeO2 nanocrystals are incorporated into these differently oriented layers. It is determined that CeO2 dispersion in the composite is higher than in pure CeO2 nanopowder. Estimating the phase and chemical purity of the synthesized composite, it can be argued that the developed method for obtaining nanostructured powders based on graphene and CeO2 is promising as the basis for an economical and environmentally friendly technology for the production of initial substances for fine-grained electrical ceramics.