▎ 摘　　要

NOVELTY - Graphene-based thermally conductive composite filler comprises high-quality graphene and elemental silver without impurities. The mass ratio between carbon, oxygen and silver elements in the composite filler is 68-92:1-5:5-30; the elemental silver in the composite filler is silver nanoparticles with particle size is 50-180 nm, and is uniformly adhered to the surface of high-quality graphene and graphene sheets. USE - The graphene-based thermally conductive composite filler is useful in thermally conductive material (claimed). ADVANTAGE - The composite filler: improves the heat dissipation efficiency of surface of electronic devices; has uniform distribution and excellent crystallinity; and is suitable for industrial production. The method: has high purity product; and is highly efficient, safe and environmentally friendly. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene-based thermally conductive composite filler, comprising (i) mixing graphene with graphite oxide to obtain mixture, where the graphene is used as microwave sensing material; and mass ratio between graphite oxide and graphene is 1:0.1-0.2, (ii) placing the mixture obtained in step (i) in microwave reactor and passing mixed gas containing argon and hydrogen gas, controlling microwave reaction power and time to obtain high-quality graphene, where the volume ratio between argon gas and hydrogen gas is 9:1, (iii) mixing high-quality graphene obtained in step (ii) with silver acetate powder to obtain mixture, where mass ratio between high-quality graphene and silver acetate powder is 1:0.1-0.7, and (iv) placing the mixture obtained in step (iii) in microwave reactor, then passing argon gas, and controlling microwave reaction power and time to obtain nano-silver-loaded graphene-based thermally conductive composite filler.