氧化石墨：制备及去除阳离子染料的性能

以石墨粉为原料按Hummers氧化法制备氧化石墨,借助X射线衍射仪(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、傅里叶变换红外光谱法(FTIR)和低温氮吸附-脱附对氧化石墨的结构和形貌进行了表征。结果表明,氧化石墨是不平整的、具有一定层状结构的褶皱片状,在其表面存在着许多含氧的官能团如:环氧基、羟基、羧基。此外还研究了氧化石墨对阳离子染料的吸附性能,结果表明:吸附过程的等温模型符合Langmuir等温式,对甲基紫、甲基绿、中性红这3种阳离子染料的最大饱和吸附量分别为:741,446和368 mg.g-1;对阳离子染料的吸附过程符合二级动力学方程。氧化石墨作为一种吸附剂能有效的去除阳离子染料与其较高的比表面积和与阳离子染料的静电吸引有关。

Graphite Oxide :Preparation and Removal Ability of Cationic Dyes

This study reports the preparation of Graphite oxide (GO) and GO as an adsorbent for removal of cationic dyes. GO was synthesized by the oxidation of graphite through the modied Hummers approach. The structure of GO was characterized by XRD, TEM, SEM, FTIR and N₂ adsorption. The results show that GO is a uneven wrinkled flake with certain layer structure and a large quantities of oxygen-containing fuctional groups exists in the form of epoxy, hydroxyl, and carboxyl groups on the surface of GO. In addition, GO has a good capability towards cationic dyes adsorption. The Langmuirian maximum adsorption capacities of GO are 741 mg·g^-1 for methyl violet, 446 mg·g^-1 for methyl green and 368 mg·g^-1 for neutral red. The adsorption processes follow the pseudosecond-order kinetics model. GO could be used potentially as an effective adsorbent for removal of cationic dyes from aqueous solution possibly due to its electrostatic attraction and large specific surface area.