Superior coagulation of graphene oxides on nanoscale layered double hydroxides and layered double oxides
Superior coagulation of graphene oxides on nanoscale layered double hydroxides and layered double oxides
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氧化石墨烯在纳米级层状双氢氧化物和层状双氧化物上的优异凝结
DOI：
10.1016/j.envpol.2016.10.052
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发表时间：
2017
影响因子：
8.9
通讯作者：
Wang Xiangke
中科院分区：
文献类型：
--
作者：
Zou Yidong;Wang Xiangxue;Chen Zhongshan;Yao Wen;Ai Yuejie;Liu Yunhai;Hayat Tasawar;Alsaedi Ahmed;Alharbi Njud S.;Wang Xiangke
随着氧化石墨烯（GO）的开发和应用，GO的潜在毒性和环境行为已成为当前最前沿的环境问题之一。本文中，合成了新型纳米级层状双氢氧化物（甘油改性的纳米微晶层状Mg/Al层状双氢氧化物，LDH-Gl）、层状双氧化物（煅烧的LDH-Gl，LDO-Gl）和金属氧化物（TiO 2），并将其作为上级混凝剂用于从水溶液中有效去除GO。研究并比较了GO的混凝性能与混凝剂用量、pH、离子强度、GO用量、温度和共存离子的关系，结果表明GO的最大混凝能力为LDO-G1（448.3 mg g−1）> TiO 2（365.7 mg g−1）> LDH-Gl（339.1 mg g−1），在pH 5.5时，其显著高于膨润土、Al 2 O3、CaCl 2或其它天然物质由于其较强的反应活性和界面效应。SO 32-和HCO 3-的存在显著抑制了GO在LDH-G1和LDO-G1上的凝聚，而其它阳离子（K+，Mg 2+，Ca 2+，Ni 2+，Al 3+）或阴离子（Cl-）对GO的凝聚影响较小。TEM、SEM、FT-IR和XRD分析表明，GO在LDO-G1和TiO 2上的凝聚作用机理可能是静电作用和强表面络合作用，而GO在LDH-G1上凝聚作用的主要驱动力可能是静电作用和氢键作用。自然环境模拟实验结果表明，LDO-Gl、TiO 2等天然金属氧化物在真实的环境污染治理中，可以作为上级混凝剂，有效去除水溶液中的GO等有毒纳米材料。
With the development and application of graphene oxides (GO), the potential toxicity and environmental behavior of GO has become one of the most forefront environmental problems. Herein, a novel nanoscale layered double hydroxides (glycerinum-modified nanocrystallined Mg/Al layered double hydroxides, LDH-Gl), layered double oxides (calcined LDH-Gl, LDO-Gl) and metallic oxide (TiO2) were synthesized and applied as superior coagulants for the efficient removal of GO from aqueous solutions. Coagulation of GO as a function of coagulant contents, pH, ionic strength, GO contents, temperature and co-existing ions were studied and compared, and the results showed that the maximum coagulation capacities of GO were LDO-Gl (448.3 mg g−1) > TiO2(365.7 mg g−1) > LDH-Gl (339.1 mg g−1) at pH 5.5, which were significantly higher than those of bentonite, Al2O3, CaCl2or other natural materials due to their stronger reaction active and interfacial effect. The presence of SO32−and HCO3−inhibited the coagulation of GO on LDH-Gl and LDO-Gl significantly, while other cations (K+, Mg2+, Ca2+, Ni2+, Al3+) or anion (Cl−) had slightly effect on GO coagulation. The interaction mechanism of GO coagulation on LDO-Gl and TiO2might due to the electrostatic interactions and strong surface complexation, while the main driving force of GO coagulation on LDH-Gl might be attributed to electrostatic interaction and hydrogen bond, which were further evidenced by TEM, SEM, FT-IR and XRD analysis. The results of natural environmental simulation showed that LDO-Gl, TiO2or other kinds of natural metallic oxides could be superior coagulants for the efficient elimination of GO or other toxic nanomaterials from aqueous solutions in real environmental pollution cleanup.