Modification of graphene aerogel with titania nanotubes for efficient methylene blue adsorption kinetics
Modification of graphene aerogel with titania nanotubes for efficient methylene blue adsorption kinetics
复制标题
二氧化钛纳米管修饰石墨烯气凝胶以实现高效的亚甲基蓝吸附动力学
DOI：
10.1007/s10971-020-05449-y
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发表时间：
2021-01-16
影响因子：
2.5
通讯作者：
Chen, Zhong
中科院分区：
文献类型：
--
作者：
Liu, Hongli;Gao, Bo;Chen, Zhong
将长径比较大的二氧化钛纳米管(TNTs)引入氧化还原石墨烯(RGO)气凝胶中，对气凝胶的孔结构进行改性，以实现对亚甲基蓝(MB)的高效吸附。采用水热结合冷冻干燥的方法制备了rGO/TNTs复合气凝胶。均匀分散在RGO基质中的TNTs可以有效地支撑网络结构，阻碍石墨烯之间的pi-pi键相互作用，从而形成具有高比表面积的三维介孔网络。RGO/TNTs气凝胶对亚甲基蓝具有良好的吸附性能，最大吸附容量为380.7 mg g-1，吸附效率为92.2%。此外，吸附动力学分析表明，当吸附剂用量较低时，分散过程是限速步骤。随着吸附剂含量的增加，MB与rGO-TNTs-C气凝胶之间的化学吸附(如pi-pi相互作用或极性官能团的反应)成为速率限制步骤。
Titania nanotubes (TNTs) with high length-diameter ratio are incorporated into reduced graphene oxide (rGO) aerogel to modify the porous structure of the obtained rGO/TNTs aerogel for efficient methylene blue (MB) adsorption. A hydrothermal method along with freeze drying is applied for the preparation of the rGO/TNTs composite aerogel. The uniformly dispersed TNTs in rGO matrix can effectively support the network structure and hinder the pi-pi bonding interaction between graphene sheets, thus resulting in a three-dimensional mesoporous network with high specific surface area. The rGO/TNTs aerogel shows favorable adsorption property toward MB and the maximum adsorption capacity can be 380.7 mg g(-1) with the adsorption efficiency of 92.2%. Besides, the adsorption kinetic analysis reveals that a dispersion process is found to be the rate-limiting step when the adsorbent dosage is low. With the increase of adsorbent content, chemical sorption such as the pi-pi interaction or the reaction of the polar functional groups between MB and rGO-TNTs-C aerogel becomes the rate-limiting step.