▎ 摘　　要

NOVELTY - An etching solution is prepared by filling glass vessel with ammonium persulfate, heating deionized water to boil at 100 degrees C, and adding boiled deionized water to glass vessel to obtain ammonium persulfate aqueous solution. USE - Preparation of etching solution for metal foil substrate graphene (claimed). ADVANTAGE - The etching solution is non-toxic and environment-friendly, and has high etching rate. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for etching method which involves spin coating protective colloid on metal foil substrate graphene surface with thickness of 0.5-2 mu m, oven drying at 60-100 degrees C for 5-15 minutes or drying at room temperature for 30-60 minutes, cooling etching solution by water bath heating at 50-80 degrees C, and immersing metal foil substrate graphene to etching solution with protective layer facing upward to obtain graphene/protective layer laminated structure.