▎ 摘　　要

NOVELTY - Preparing graphene by using large seaweed as raw material involves placing large seaweed powder after washing, drying, and pulverizing in a vacuum tube furnace, heating to 300-500 degrees C under a nitrogen atmosphere, and heat-treating for 1-3 hours to obtain solid biochar. The alkali is mixed with the obtained biochar, fully immersed to make the mixture uniform, heat treatment under nitrogen gas, so that the alkali activates the biochar at high temperature. The obtained sample is treated with an acid solution, and then filtered, the obtained solid is washed with water until the washing solution is neutral, and the obtained solid is dried to obtain graphene. USE - Method for preparing graphene. ADVANTAGE - The method enables to prepare graphene with abundant resources and low cost as raw materials, and simultaneously improving the high value-added comprehensive utilization of large seaweeds.