▎ 摘　　要

NOVELTY - A composite material preparation method involves preparing graphene oxide aqueous solution, followed by soaking nickel foam in graphene oxide aqueous solution to obtain graphene oxide loaded with nickel foam material. The obtained material is dried to obtain nickel foam-graphene oxide composite product, followed by dissolving palladium acetylacetonate and potassium halide in N,N-dimethylformamide to obtain mixed solution. The nickel foam-graphene oxide composite product is soaked in mixed solution, followed by reacting, cooling, separating, cleaning and drying. USE - Method for preparing composite material. ADVANTAGE - The method enables preparing composite material by slowing reduction of graphene oxide laminate and irreversible agglomeration of graphene oxide, obtaining palladium particles having particle size of 10-60 nm, achieving uniform distribution of the graphene oxide and sufficiently increasing electrocatalytic activity of palladium nanoparticles. DETAILED DESCRIPTION - A composite material preparation method involves preparing 1-10 mg/ml graphene oxide aqueous solution, followed by soaking nickel foam in graphene oxide aqueous solution and ultrasonically processing to obtain graphene oxide loaded with nickel foam material. The obtained material is dried to obtain nickel foam-graphene oxide composite product, followed by dissolving palladium acetylacetonate and potassium halide in N,N-dimethylformamide to obtain mixed solution. The nickel foam-graphene oxide composite product is soaked in mixed solution, followed by reacting at 100-200 degrees C for 1-6 hours, cooling, separating, cleaning and drying, where nickel foam is utilized as substrate, concentration of the palladium acetylacetonate in N,N-dimethylformamide is 2 g/ml and concentration of the potassium halide in N,N-dimethylformamide is 0.1-4 mg/10 ml. An INDEPENDENT CLAIM is also included for a composite material comprising palladium nanoparticles having particle size of 10-60 nm.