磷酸化石墨烯吸附铀的性能研究  

Adsorption of uranium by phosphorylated graphene oxide

作　　者：张志宾[1,2] 张昊岩 邱燕芳[1] 陈海军 戴荧[1] 刘云海[1] 曹小红[1] Zhibin Zhang;Haoyan Zhang;Yanfang Qiu;Haijun Chen;Ying Dai;Yunhai Liu;Xiaohong Cao(State Key Laboratory Breeding Base of Nuclear Resources and Environment,East China University of Technology,Nanchang 330013,China;College of Environmental Science and Engineering,North China Electric Power University,Beijing 102206,China)

机构地区：[1]东华理工大学核资源与环境国家重点实验室,南昌330013 [2]华北电力大学环境科学与工程学院,北京102206

出　　处：《中国科学：化学》2019年第1期195-206,共12页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(编号:21561002;21866003;21866004);国家博士后基金(编号:2016M600981);江西省杰出青年基金(编号:2018ACB21007)资助项目

摘　　要：本文利用简单的原位磷酸化反应,成功地将磷酸基团接枝到氧化石墨烯的表面,制备了一种磷酸化石墨烯吸附材料(PGO).采用扫描电子显微镜(SEM)和透射电子显微镜(TEM)表征了PGO的微观形貌,通过傅里叶转换红外光谱(FT-IR)、X射线光电子能谱(XPS)和拉曼光谱(Raman)等表征了PGO表面官能团的结构.结果表明,磷酸基团通过与GO中的C–O–C反应引入.系统研究了pH、离子强度、温度和时间等对PGO吸附铀性能的影响. pH是影响吸附铀过程的主要因素,吸附过程受离子强度影响较弱,说明PGO的吸附受内层表面络合控制;吸附过程符合Langmuir模型,单分子饱和吸附容量为396.83 mgg^(-1),高于GO (249.38 mgg^(-1));吸附过程符合准二级动力学模型,证明化学吸附占有主导地位;热力学参数(ΔG、ΔH、ΔS)表明吸附过程是吸热和自发的; PGO吸附铀的选择率高达56%,用1.0 molL^(-1)HCl洗脱时,脱附率达到98%; 5次吸附、脱附循环后PGO的吸附量仅降低了13%.磷酸化石墨烯在放射性废水处理领域具有广阔的应用前景.A novel phosphorylated graphene oxide(PGO)adsorbent material was synthesized by chemical grafting.The morphology and structure were characterized by scanning electron microscopy(SEM)and transmission electron microscope(TEM).The Fourier transform infrared spectroscopy(FT-IR)spectrum,X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy were used to investigate the functional groups on the surface of adsorbents.It was confirmed that the phosphate groups were introduced onto the surface of graphene oxide by reacting with C-^O-C.In addition,the effect of environmental factors including pH,ionic strength,temperature,and contact time for the adsorption of U(VI)were investigated by batch experiments.The U(VI)sorption process of PGO was clearly pHdependent,showing that the adsorption was driven by complexes between the interior surface of PGO and uranyl ions.The adsorption process was dominanted by the Langmuir isotherm model and the pseudo-second-order model,indicating that chemisorption controlled the adsorption.The adsorption capacity of U(VI)onto PGO reaches 396.83 mg g1,that is significantly higher than that of the GO(249.38 mg g_1).The selectivity was above 56%.The adsorption thermodynamic model calculation indicated that the sorption process was endothermic and spontaneous.The 0.1 mol L_1 HC1 solution was selected as elution solvent for the study of reusability of PGO,and the desorption rate reaches 98%.After the five adsorption-desorption cycles,the absorption of PGO was decreased only 13%,demonstrating that PGO maintains excellent repeatability.

关 键 词：化学接枝 石墨烯 铀 选择性 吸附 

分 类 号：O647.3[理学—物理化学]