One-pot hydrothermal synthesis of graphene–RuO2–TiO2 nanocomposites

• A ternary graphene–RuO2–TiO2 nanocomposite is prepared via an in-situ co-assembly.
• A unique morphology of graphene sheets loaded with sporadic spots or coatings.
• The coverage of coatings can be tuned by altering the precursor ratios of Ru/Ti
• The nanocomposite shows strong potential for applications in energy storage.

A porous ternary nanocomposite based on graphene, RuO2 and TiO2 has been prepared via a facile in-situ co-assembly without any surfactants. A unique morphology of highly-curled graphene sheets loaded with sporadic spots or coatings comprised of mixed RuO2 and TiO2 nanodots was achieved for the first time. This uniform decoration indicates strong interaction between graphene and the as-grown nanoparticles favoring the full separation of graphene sheets. The formation mechanism of such a porous but tightly bonded hetero-nanostructure benefiting from linking effect of TiO2 is proposed. Electrochemical tests showed a characteristic capacitive behavior and the specific capacitance values of 216.7–396.5 F/g depending on the ratios of Ru/Ti, which has potential for energy storage.