▎ 摘　　要

NOVELTY - Preparing modified graphene comprises dispersing graphene oxide in de-ionized water to obtain graphene oxide suspension, adding phosphatidylserine, stirring and reacting under presence of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and 4-dimethylaminopyridine (DMAP), repeatedly washing product obtained by reaction until pH is close to neutral, and drying. USE - The method is useful for preparing modified graphene, which is useful for preparing heavy metal ion absorbing material i.e. lead ion adsorbent for treating lead ion-containing wastewater and/or repairing lead ion-contaminated soil, promoting plant growth (all claimed), increasing activity of soil urease and acid phosphatase, and improving soil quality. ADVANTAGE - The lead ion adsorbent has large specific surface area and better lead ion adsorption capacity. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) modified graphene, prepared by above method; (2) lead ion adsorbent, comprising sodium alginate/modified graphene pellets; and (3) preparing the lead ion adsorbent, comprising: (i) dispersing modified graphene and sodium alginate in de-ionized water, stirring to form uniform solution, dropping mixed solution into calcium chloride solution, maintaining formed microsphere in calcium chloride solution, filtering and washing with de-ionized water, and drying.