▎ 摘　　要

NOVELTY - Graphene composite comprises graphene, transition metal nanoparticle, and silver, where the transition metal nanoparticle is carbide-bonded to the surface of the graphene, and the transition metal nanoparticles have an average particle diameter of 10-100 nm, and distributed on the surface of the graphene, the silver (Ag) forms a coating layer on the surface of the transition metal nanoparticles, the coating layer has an average thickness of 4 nm, and the silver is the graphene and carbide (carbide) does not form a bond, in this case, the transition metal nanoparticles are included in greater than or equal to 1 wt.% and less than or equal to 4 wt.% of the total weight of the composite, and the silver (Ag) is greater than or equal to 1 wt.% and less than or equal to 4 wt.% of the total weight of the composite. USE - The graphene composite is useful in an ink composition for printed electronics. ADVANTAGE - The graphene composite has improved sheet resistance by using only a small amount of expensive silver. The ink for printed electronics has low sheet resistance and is easy to print with a fine line width, can be used for printed electronics of various materials without being limited to the material. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) an ink composition for printed electronics comprising water or an organic solvent and graphene composite; and (2) preparing the graphene composite comprising (i) immersing graphene chemically bonded to transition metal nanoparticles on the surface in a solution of tin (Sn), palladium (Pd) and acid, where tin and palladium are ionized in the solution, and as the tin ions are oxidized, the palladium ions are reduced to metal palladium and are chemically adsorbed on the surface of the transition metal nanoparticles, (ii) immersing the product obtained in the step (i) in a solution containing silver ions, (iii) treating the reducing agent, where the silver ions are reduced to metallic silver by receiving electrons from the reducing agent to coat the surface of the transition metal nanoparticles on which palladium is adsorbed, and (iv) obtaining the graphene composite.