磁性氧化石墨烯制备和去除水中刚果红的研究.pdf

中国环境科学 2013,33(8) ：1379~1385 China Environmental Science 磁性氧化石墨烯制备及去除水中刚果红的研究 * 张秀蓉,龚继来, 曾光明,邓久华 ( , 410082) 湖南大学环境科学与工程学院湖南长沙 摘要：采用Hummer 方法制备了氧化石墨烯(GO),采用化学共沉淀法把铁氧化物纳米粒子覆盖在GO 上制成磁性氧化石墨烯(MGO),并把 MGO 用作吸附剂去除水中阴离子染料刚果红.采用扫描电镜(SEM)、透射电镜(TEM)、Zeta 电位仪和磁强计对MGO 进行了表征.研究了吸 附动力学,吸附等温线及初始pH 值,离子强度对吸附的影响.考察了MGO 对自来水中刚果红的去除效果.结果表明,GO 具有片状的二维纳 米结构,表面有许多的褶皱; 当pH3.5, 吸附剂表面带正电荷, 当pH3.5, 吸附剂表面带负电荷,等电点为3.5;MGO 的饱和磁化强度为 31.2emu/g,足够从水溶液中分离出来.刚果红的吸附符合准二级动力学模型,且在吸附时间为7h 内基本达到吸附平衡.在超纯水中最大吸附 容量高达140.6mg/g,且吸附量随pH 值升高先增加再降低,当pH4~5 达到最大值.MGO 对自来水中刚果红的最大吸附容量为287.6 mg/g,为 在超纯水中的2 倍,表明MGO 对刚果红具有很好的去除效果. 关键词：磁性氧化石墨烯；吸附；刚果红 中图分类号：X703.5 文献标识码：A 文章编号：1000-6923(2013)08-1379-07 Synthesis of magnetic graphene oxide adsorbent for congo red removal from aqueous solution. ZHANG Xiu-rong, GONG Ji-lai*, ZENG Guang-ming, DENG Jiu-hua (College of Environmental Science and Engineering, Hunan University, Changsha 410082, China). China Environmental Science, 2013,33(7)：1379~1385 Abstract ：Graphene oxide (GO) was synthesized using Hummer’s method and magnetic graphene oxide (MGO) was prepared by coprecipitation of iron oxide nanoparticles on GO nanosheets. MGO was used as adsorbent for removing anionic dye congo red from aqueous solution and was characterized by scanning electron microscope(SEM), transmission electron microscope (TEM), Zeta SIZER and vibrating sample magnetometer(VSM). Adsorption kinetics, isotherms, the effects of initial pH and ionic strength on adsorption, and congo red removal efficiency in tap water were also investigated. Results showed that GO exhibited layered 2D nanostructure with many wrinkles on the surface. The surface charge was positive at pH3.5, but was negative at pH3.5, the pH PZC value of MGO was 3.5. The saturation magnetization of MGO adsorbe