▎ 摘　　要

NOVELTY - Preparing graphene-coated metal nanoparticle, comprises using tartrate metal salt as raw material, pyrolyzing at 700-1200℃ for 20-120 minutes under the protection of nitrogen and/or inert gas, and gradually catalyzing carbon-containing compounds at high temperatures to directly grow graphene in situ on the surface of metal nanoparticles due to the in-situ pyrolysis of tartrate metal salts at high temperatures to produce metal nanoparticles and carbon-containing compounds and simultaneously forming a coating layer, thus a one-step method is realized to prepare graphene-coated metal nanoparticles. USE - The method is useful for preparing graphene-coated metal nanoparticle. ADVANTAGE - The method provides metal graphene particle with controllable parameters e.g. graphene layer number and metal nanometre particle size. The method does not need additional carbon source and auxiliary gas. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for regulating and controlling the number of layers of graphene in graphene-coated metal nanoparticles.