▎ 摘　　要

NOVELTY - The method involves coating a porous carbon metal catalyst layer of a graphene oxide three-dimensional network colloid on a surface of a pre-treated Titanium plate substrate. The pre-treated Titanium plate substrate is decompressed and dehydrated at 50 to 70 degrees centigrade. The pre-treated Titanium plate substrate is frozen and dried to obtain a porous carbon metal catalyst layer with a three-dimensional graphene network. A surface of the porous carbon metal catalytic layer surface is added with graphene oxide solution. The surface of the porous carbon metal catalytic layer surface is vacuum dried at 50 to 70 degrees centigrade. A layer of a compact graphene film is formed on the three-dimensional graphene network surface. An electrode is sintered at 400 to 900 degrees centigrade to obtain a composite electrode for generating hypochlorous acid by electrolysis. USE - Method for preparing a composite electrode (claimed) based on generating hypochlorous acid by electrolysis for preparing plant extract coupling. ADVANTAGE - The method enables preparing the composite electrode with high catalytic activity and stability, low cost, long service life.