▎ 摘　　要

NOVELTY - The preparation method involves providing electrochemical reaction device. The electrochemical reaction device includes a carbon electrode (2), a metal electrode (4) and an electrolyte solution (3). The metal electrode is used as the anode and the carbon electrode is used as the cathode, and the first electrochemical reaction is carried out after electrification. The metal electrode is used as the cathode, the carbon electrode is used as the anode, and the second electrochemical reaction is carried out after electrification. The first electrochemical reaction and the second electrochemical reaction are cycled 0-N times, N≥1. USE - Preparation method of graphene or metal composite material used in electronic catalytic applications, and material chemical field. ADVANTAGE - The grapheme or metal composite material has good electrical and thermal properties. The graphene quantum dot solution as electrolyte solution is environment-friendly and pollution-free, and improves the product shape and product quality. The sheet metal is tightly combined with the graphene sheet, and obvious agglomeration is avoided. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a graphene or metal composite material. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of electrochemical reaction device in preparation method of grapheme or metal composite material. 1Constant voltage direct current (DC) power supply 2Carbon electrode 3Electrolyte solution 4Metal electrode