氧化石墨烯对铀的高效吸附研究:批试验和理论计算
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- 英文论文题名：High sorption of U(Ⅵ) on graphene oxides studied by batch experimental and theoretical calculations
- 论文作者：陈中山 ; 王祥科
- 英文论文作者：Chen Zhongshan ; Wang Xiangke ; School of Chemistry and Environment ; North China Electric Power University
- 年：2016
- 作者机构：华北电力大学环境与化学工程系;
- 论文关键词：氧化石墨烯 ; 铀 ; 表面络合 ; DFT计算
- 会议召开时间：2016-07-01
- 会议录名称：中国化学会第30届学术年会摘要集-第二十六分会：环境化学
- 语种：中文
- 分类号：O613.71;O647.3
- 学会代码：ZGHY
- 会议名称：中国化学会第30届学术年会-第二十六分会 ; 环境化学
- 会议地点：中国辽宁大连
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：2
- 文件大小：241k
- 原文格式：D
- 会议级别：全国
摘要
我们研究了氧化石墨烯在不同实验条件下对溶液中铀的吸附特性。研究结果表明,氧化石墨烯对铀的吸附受pH值的影响很大,受离子强度的影响不明显。通过进一步的理论计算,我们发现氧化石墨烯在pH值4.5和温度20℃条件下的理论饱和吸附量为1330mg/g,这一数据比当今现有的任何其他吸附材料的饱和吸附量都大。我们对铀和氧化石墨烯之间的作用机制进行了DFT计算,计算结果证实了pH值的变化将会明显改变氧化石墨烯上官能团周围的环境。随着pH值的增大,氧化石墨烯对铀的吸附机制由低pH值条件下较弱的物理吸附或者外层表面络合转变为较强的化学吸附或者是内层表面络合,这个过程是由于高pH值条件下氧化石墨烯表面的官能团发生了去质子化反应,形成了带负电荷的-O-或者是-COO-基团。
Herein,the GOs were applied as adsorbents to remove U(VI) from aqueous solutions at different experimental conditions,and the results showed that the sorption of U(VI) on GOs was strongly dependent on pH and was notaffected by ionic strength obviously.The sorption capacity of U(VI) on GOs is calculated to be 1330 mg/g at pH 4.5 and T = 20 C,which is much higher than any other today's materials.The interaction mechanism of U(VI) on GOs was simulated by the computational DFT calculations,and the results evidenced that the variation in pH values led to significant changes in the circumstance of functional groups on GOs.As the pH value increased,the weak physical sorption/outer-sphere surface complexation between the GOs and U(VI) at low pH turned into strong chemical sorption/inner-sphere surface complexation with the negative charged –O or –COO groups induced by the deprotonation of the functional groups at high pH.
Herein,the GOs were applied as adsorbents to remove U(VI) from aqueous solutions at different experimental conditions,and the results showed that the sorption of U(VI) on GOs was strongly dependent on pH and was notaffected by ionic strength obviously.The sorption capacity of U(VI) on GOs is calculated to be 1330 mg/g at pH 4.5 and T = 20 C,which is much higher than any other today's materials.The interaction mechanism of U(VI) on GOs was simulated by the computational DFT calculations,and the results evidenced that the variation in pH values led to significant changes in the circumstance of functional groups on GOs.As the pH value increased,the weak physical sorption/outer-sphere surface complexation between the GOs and U(VI) at low pH turned into strong chemical sorption/inner-sphere surface complexation with the negative charged –O or –COO groups induced by the deprotonation of the functional groups at high pH.
引文
[1]C.C.Ding,W.C.Cheng,Y.B.Sun,X.K.Wang,,Geochim.Cosmochim.Acta 165(2015)86-107.
[2]Y.B.Sun,S.B.Yang,Y.Chen,C.C.Ding,W.C.Cheng,X.K.Wang,Environ.Sci.Technol.49(2015)4255-4262.
[2]Y.B.Sun,S.B.Yang,Y.Chen,C.C.Ding,W.C.Cheng,X.K.Wang,Environ.Sci.Technol.49(2015)4255-4262.