Nanocomposite of carbon nanotubes/silica nanoparticles and their use for adsorption of Pb(II): from surface properties to sorption mechanism
Nanocomposite of carbon nanotubes/silica nanoparticles and their use for adsorption of Pb(II): from surface properties to sorption mechanism
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DOI：
10.1080/19443994.2015.1036784
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发表时间：
2016-05-14
影响因子：
1.1
通讯作者：
Saleh, Tawfik A.
中科院分区：
文献类型：
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作者：
Saleh, Tawfik A.
本文主要研究了多壁碳纳米管和二氧化硅纳米复合材料（CNT/SiO2）的合成。通过扫描电子显微镜、能量色散X射线光谱仪、傅里叶变换红外光谱仪和高分辨率透射电子显微镜研究观察到MWCNT/SiO2纳米结构的成功实现。所制备的纳米复合材料作为吸附剂进行评价，以去除铅，Pb（II），从水溶液中。所得的MWCNT/SiO2表现出有利的吸附性能（类似于95%）超过二氧化硅纳米颗粒（类似于50%）和CNT（类似于45%）。Lagergren的伪一阶，伪二阶和颗粒内扩散模型被用来分析在不同的初始Pb（II）浓度下获得的动力学数据。吸附动力学数据符合准二级动力学模型，相关系数为0.99。吸附过程的活化能E-a为15.8kJ·mol ~（-1）。吸附数据可以用Langmuir和Temkin模型描述。H度（29.4kJ/mol）和S度（116.8J/molK）均为正值，表明Pb（II）在纳米复合材料上的吸附过程中发生了吸热反应，并增加了固液界面的随机性。负的G度值指示自发吸附过程。元素色散X射线分析和映射证实了吸附的Pb（II）的纳米复合材料表面上。这项工作还强调了纳米复合材料的可回收性，具有高效率，并支持其在环境应用中的潜力。可以预见，这些结果在吸附领域具有广泛的潜力，用于设计高效和可重复使用的吸附剂。
This paper demonstrates the synthesis of multi-wall carbon nanotubes and silica nanocomposite (CNT/SiO2). Successful realization of MWCNT/SiO2 nanostructure was observed by scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and high-resolution transmission electron microscopy studies. The as-prepared nanocomposite was evaluated as an adsorbent to remove lead, Pb(II), from aqueous solutions. The resulting MWCNT/SiO2 manifests propitious adsorption performance (similar to 95%) over silica nanoparticles (similar to 50%) and CNTs (similar to 45%). Lagergren's pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyse the kinetic data obtained at different initial Pb(II) concentrations. The adsorption kinetic data were described well by the pseudo-second order model with R-2 of 0.99. The activation energy (E-a) of the adsorption process was calculated as 15.8kJmol(-1). Adsorption data were described well by the Langmuir and Temkin models. The positive values of both H degrees (29.4 kJ/mol) and S degrees (116.8J/molK) obtained suggest an endothermic reaction and in increase in randomness at the solid-liquid interface during the adsorption of Pb(II) on the nanocomposite. The negative G degrees values indicate a spontaneous adsorption process. Elemental dispersive X-ray analysis and mapping confirmed the adsorption of Pb(II) on the nanocomposite surface. The work also highlights the recyclability of the nanocomposite with high efficiencies and supports its potential for environmental applications. It is anticipated that the results bear broad potential in the sorption domain for the design of efficient and reusable adsorbent.