功能化石墨烯选择性吸附重金属离子

Functionalized Graphene for selective adsorption of heavy metal ions

重金属离子污染日益严重,石墨烯作为一种新型碳材料在吸附重金属离子方面具有巨大潜力。本文通过尝试,探索出基于酯化反应将功能团乙二胺四乙酸(EDTA)连接到氧化石墨烯(GO)表面合成功能化氧化石墨烯(EDTA-GO)的新方法。研究结果显示:EDTA-GO饱和吸附量高达(355±17)mg/g,较改性之前提高了17.5%,并且符合Langmuir单层吸附模型。随着pH值的升高,EDTA-GO的吸附性能越来越强。吸附平衡时间在4分钟以内。通过将Pb^(2+)与Cd^(2+)和Cu^(2+)相比较,发现在pH=4.6的条件下Pb^(2+)的饱和吸附量远大于后两者,表现出良好的选择性吸附特点。

Water pollution duing to heavy metal ions becomes heavier and heavier. As a novel carbon material, graphene has a unique potential for absorbing heavy metal ions. We find a new method tosynthesizing EDTA-GO,by which EDTA could connect to the surface of graphene oxide（GO） based on the esterification reaction. The results show that： theadsorption capacity of Pb（II） by EDTA-GO was（355 ± 17） mg/g at pH 4.6,whichincrease 17.5% than GO. The Langmuiradsorption model agrees with the experimental data, and theadsorption process was completed in 4 minutes. With the increase of pH, the adsorption property of EDTA-GO also has been stronger. Compared with Cd（II） and Cu（II）, theadsorption capacity for Pb（II） by EDTA-GO is much larger at pH 4.6.