▎ 摘　　要

NOVELTY - A heavy metal adsorbent comprises graphene and nano-magnesium oxide composite synthetic compound. The graphene is present at 0.1-10 wt.%. The grain diameter of the nano-magnesium oxide is 10-100 nm. USE - Heavy metal adsorbent. ADVANTAGE - The heavy metal adsorbent has excellent heavy metal adsorption performance, simple and easy to operate preparation method. The preparation method is suitable for industrial production. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for the preparation of heavy metal adsorbent comprising: (A) carrying out chemical oxidation method to prepare graphite oxide; (B) ultrasonic cleaning the graphite oxide into an ultrasonic cleaner for 2 hours, obtaining the graphene oxide solution, adding sodium borohydride solution into the graphene oxide solution, and adding soluble magnesium salts solution and citric acid solution and stirring; (C) heating solution at 80 degrees C, stirring into sol solution for 2-3 hours, and continuously stirring for 1-2 hours to form gel; and (D) putting the obtained gel into a muffle furnace, foaming at 150 degrees C, calcining at 450-600 degrees C for 1-3 hours under the air atmosphere.