▎ 摘　　要

NOVELTY - Preparing graphene-ruthenium oxide nanocomposite material involves reacting citric acid and histidine in molar ratio of 1:2-2:1 at 150-200 degrees C to obtain graphene quantum dots, dispersing the graphene quantum dots in deionized water to obtain graphene quantum dots aqueous solution, dispersing graphene oxide in deionized water to obtain graphene oxide aqueous solution, adding the graphene quantum dot aqueous solution to the graphene oxide aqueous solution with stirring, adjusting the pH to neutral to obtain a mixture, adding the ruthenium source solution, collecting the precipitate, washing the precipitate with deionized water and drying to obtain the ruthenium-graphene oxide composite. The obtained ruthenium-graphene oxide composite is calcined at 600-1000 degrees C for 1-10 hours in a gas atmosphere to obtain a ruthenium-graphene nanocomposite. USE - Method for preparing graphene-ruthenium oxide nanocomposite material used in electrochemical field (claimed). ADVANTAGE - The method is simple, helps in forming small sized ruthenium oxide nano-particles uniformly dispersed on the graphene sheet, helps to avoid nano-particle accumulation and makes the ruthenium oxide to have a larger specific surface area. DETAILED DESCRIPTION - Preparing graphene-ruthenium oxide nanocomposite material involves reacting citric acid and histidine in molar ratio of 1:2-2:1 at 150-200 degrees C to obtain graphene quantum dots, dispersing the graphene quantum dots in deionized water to obtain graphene quantum dots aqueous solution, dispersing graphene oxide in deionized water to obtain graphene oxide aqueous solution, adding the graphene quantum dot aqueous solution to the graphene oxide aqueous solution with stirring, adjusting the pH to neutral to obtain a mixture, adding the ruthenium source solution, collecting the precipitate, washing the precipitate with deionized water and drying to obtain the ruthenium-graphene oxide composite. The obtained ruthenium-graphene oxide composite is calcined at 600-1000 degrees C for 1-10 hours in a gas atmosphere to obtain a ruthenium-graphene nanocomposite. The ruthenium-graphene nanocomposite material is heat-treated at a low temperature under an air atmosphere to obtain a graphene-ruthenium oxide nanocomposite material. The temperature of the low-temperature heat treatment is 100-300 degrees C, and the treatment time is 1-10 hours.