Adsorption behavior of methylene blue onto titanate nanotubes.
Adsorption behavior of methylene blue onto titanate nanotubes.
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DOI：
10.1016/j.cej.2009.10.023
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发表时间：
2010-01
影响因子：
15.1
通讯作者：
Lin Xiong;Ye Yang;Jiaxing Mai;Weiling Sun;Chaoying Zhang;Dapeng Wei;Qing Chen;J. Ni
中科院分区：
文献类型：
--
作者：
Lin Xiong;Ye Yang;Jiaxing Mai;Weiling Sun;Chaoying Zhang;Dapeng Wei;Qing Chen;J. Ni
采用水热法对商用二氧化钛（Degussa P25）进行处理，然后进行煅烧，合成了煅烧钛酸盐纳米管。采用透射电镜、x射线衍射和n2吸附/脱附等手段对制备的样品进行了形貌和结构表征。样品呈管状结构，比表面积高达157.9m2/g。研究了焙烧钛酸盐纳米管对亚甲基蓝的吸附。采用准一级、准二级和Weber粒子内扩散模型对吸附动力学进行了评价。拟二阶模型最能描述吸附动力学，颗粒内扩散不是限速步骤。采用Langmuir模型、Freundlich模型和Temkin模型对平衡吸附数据进行了分析。Langmuir等温线的相关系数为0.993，最大吸附量为133.33mg/g。吸附机制主要归因于化学吸附，包括亚甲基蓝煅烧钛酸盐纳米管纳米复合材料的形成，并与初始体扩散中的静电吸引有关。
Calcined titanate nanotubes were synthesized with hydrothermal treatment of the commercial TiO2(Degussa P25) followed by calcination. The morphology and structures of as-prepared samples were investigated by transmission electron microscopy, X-ray diffraction and N2adsorption/desorption. The samples exhibited a tubular structure and a high surface area of 157.9m2/g. The adsorption of methylene blue onto calcined titanate nanotubes was studied. The adsorption kinetics was evaluated by the pseudo-first-order, pseudo-second-order and Weber's intraparticle diffusion model. The pseudo-second-order model was the best to describe the adsorption kinetics, and intraparticle diffusion was not the rate-limiting step. The equilibrium adsorption data were analyzed with three isotherm models (Langmuir model, Freundlich model and Temkin model). The best agreement was achieved by the Langmuir isotherm with correlation coefficient of 0.993, corresponding to maximum adsorption capacity of 133.33mg/g. The adsorption mechanism was primarily attributed to chemical sorption involving the formation of methylene blue-calcined titanate nanotubes nanocomposite, associated with electrostatic attraction in the initial bulk diffusion.