Application of graphene oxides for the removal of Pb(II) ions from aqueous solutions: Experimental and DFT calculation
Application of graphene oxides for the removal of Pb(II) ions from aqueous solutions: Experimental and DFT calculation
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DOI：
10.1016/j.molliq.2015.08.020
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发表时间：
2015-11-01
影响因子：
6
通讯作者：
Yang, Shubing
中科院分区：
文献类型：
--
作者：
Wang, Xiangxue;Chen, Zhongshan;Yang, Shubing
氧化石墨烯因其特殊的物理化学性质和潜在的应用前景而引起了多学科的广泛关注。GO表面上的大量含氧官能团使得可以与金属离子形成强的表面络合物。本文采用改进的Hummers法合成了纳米TiO2，并采用SEM、TEM、FTIR、XRD、XPS和拉曼光谱等技术对纳米TiO2进行了详细的表征。结果表明，在合成过程中，GO表面生成了大量的含氧官能团。该吸附剂被应用于从水溶液中去除Pb（II）离子，并且Pb（II）的吸附强烈地依赖于pH，并且Pb（II）的吸附主要归因于强表面络合物的形成。比较不同材料对Pb（II）的吸附能力，在当今的材料中，硅藻土的吸附能力最高。远红外光谱分析和密度泛函理论计算的结果也表明Pb（II）在Pb2+上的结合主要是由于COOH基团而不是其他官能团。如果能够大规模、低成本地合成出金属螯合物，那么金属螯合物在不久的将来可能成为从大体积水溶液中富集重金属离子的合适材料。(C)2015 Elsevier B.V.版权所有。
Graphene oxides (GOs) have attracted intense multidisciplinary study because of their special physicochemical properties and their possible applications. The large amount of oxygen-containing functional groups on GO surfaces makes it possible to form strong surface complexes with metal ions. Herein, the GOs are synthesized by modified Hummers method and characterized by SEM, TEM, FTIR, XRD, XPS and Raman spectroscopy techniques in detail. The results show that large amount of oxygen-containing functional groups is generated on GO surfaces during the synthesis process. The GOs are applied as adsorbents to remove Pb(II) ions from aqueous solutions and the sorption of Pb(II),is strongly dependent on pH and the sorption of Pb(II) is mainly attributed to the formation of strong surface complexes. Comparing the sorption capacities of Pb(II) on different materials, the GOs have the highest sorption capacity among todays' materials. The results of far infrared spectroscopy analysis and the DFT calculation also indicate that the binding of Pb(II) on GOs is mainly attributed to the COOH groups rather than other functional groups. The GOs may be suitable materials for the preconcentration of heavy metal ions from large volume of aqueous solutions in the near future if GOs could be synthesized in large scale at low price. (C) 2015 Elsevier B.V. All rights reserved.