UiO-66-AO的制备及其对铀的吸附

Preparation of UiO-66-AO and Its Adsorption for Uranium

通过氮杂-迈克尔加成和胺肟化反应制备出UiO-66-AO材料,利用傅里叶变换红外光谱(FTIR)、X射线光电能谱(XPS)、X射线衍射(XRD)等手段对材料微观性质进行表征研究。深入考察了溶液的pH值、U(Ⅵ)初始浓度和温度等环境因素对吸附性能的影响。结果表明:UiO-66-AO材料对U(Ⅵ)的吸附在pH=5、4 h就达到平衡,吸附过程符合准二级动力学模型;在pH=5、55℃时,吸附容量可达到244 mg/g,吸附过程符合Langmuir等温吸附模型;该吸附是一个自发、吸热反应过程。此外,UiO-66-AO在众多其它金属离子存在情况下对U(Ⅵ)也具有优异的吸附效率。

UiO-66-AO material was prepared by Aza-Michael addition and amidoxime reaction,and was well characterized by Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and X-ray diffractometer(XRD).To evaluate the selective adsorption capacity of UiO-66-AO for U(Ⅵ)from radioactive wastewater,the adsorption experiment of U(Ⅵ)on UiO-66-AO was studied by batch adsorption technique.The effect of environmental conditions,such as solution pH,initial U(Ⅵ)concentration,and temperature were studied in detail.The experimental results show that the adsorption process reaches equilibrium in 4 h at pH=5,and follows the pseudo-second-order kinetic model.The maximum adsorption capacity of UiO-66-AO for U(Ⅵ)can reach to 244 mg/g at 55℃and pH=5,and it can be well described by Langmuir isotherm adsorption model.In addition,UiO-66-AO has excellent adsorption efficiency for U(Ⅵ)in the presence of many other metal ions.