氧化石墨烯插层膨润土复合材料高效吸附碱性紫3染料

通过超声途径，利用氧化石墨烯（GO）插层膨润土（Bent）制备复合材料（BGO），并评估对碱性紫3的吸附效果。采用XRD、FTIR、BET、SEM、XPS等检测手段表征了复合材料的结构特征，通过Langmuir、Freundlich模型和伪一级、伪二级模型拟合了等温吸附数据和动力学吸附数据，范特霍夫方程研究热力学过程。结果表明：GO成功插入Bent层间，XRD图谱显示膨润土层间距从1.35nm（Bent）扩大至1.6nm（BGO），BGO比表面积有大幅提升；吸附数据符合Langmuir等温线模型和伪二级动力学模型，在30℃、250mg/L初始浓度下，BGO最高吸附容量可达420.17mg/g，与Bent相比，BGO显示更强的吸附能力，吸附过程展现快速动态；热力学研究表明吸附过程是自发且吸热的。机理分析表明，高比表面积GO及所带含氧基团与Bent之间的协同作用共同决定BGO具有高吸附能力。

Highly efficient adsorption of Basic Violet 3 dye by composite material derived from graphene oxide intercalated bentonite

The composite materials (BGO) prepared by graphene oxide (GO) and bentonite (Bent) through ultrasound method were tested for their ability to absorb Basic Violet 3. The materials structure were characterized by X-ray Diffraction, Fourier Transform Infra-Red Spectrophotometer, BET equation, Scanning Electron Microscope and X-ray Photoelectron Spectroscopy. The biosorption data were analyzed using Langmuir, Freundlich, pseudo-first-order kinetic model and pseudo-second-order kinetic model, and the thermodynamic parameters of the biosorption were determined by Van’t Hoff equation. XRD analysis indicated that the interlayer spacing of Bent increased from 1.35nm to 1.6nm after GO were inserted successfully, and the specific surface area of BGO were improved significantly. Langmuir model and pseudo-second-order kinetic model proved to be the best fit to the experimental data. BGO performed more significant adsorption capacity and adsorption speed. Compared with Bent, the maximum adsorption capacity of BGO was 420.17mg/g at an initial dye concentration of 250mg/L and 30℃. Thermodynamic analysis verified that BGO biosorption was spontaneous and endothermic. Mechanism analysis revealed that the synergy between GO with high specific surface area and oxygen-containing groups and Bent played a prominent role in adsorption ability of BGO.