Fundamental studies involving divalent ion intercalated graphene-based hydrogel are still lacking in terms of their adsorption behavior towards dye pollutants. In this study, we prepared a self-assembled Mg²⁺ and Ca²⁺ intercalated reduced graphene hydrogel (rGH) using hydrothermal treatment to evaluate the intercalation impact on the adsorption capability towards cationic dyes, methylene blue and rhodamine B. The morphological, structural, thermal, and textural properties of the divalent ion intercalated reduced graphene hydrogels were studied using Fourier transform infrared spectrometer, thermogravimetric analysis, Raman spectroscopy, scanning electron microscope-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller surface area analysis, and X-ray diffraction. The increased adsorption capacity of the divalent ion intercalated reduced graphene-based hydrogels towards the dye molecules resulted from the increase in the specific surface area and pore volume due to the Mg²⁺ and Ca²⁺ bridging that formed spaces between the graphene sheets framework. Adsorption kinetics and the equilibrium adsorption isotherm were fitted by a pseudo-second-order alongside intraparticle diffusion kinetic models and Langmuir isotherm respectively. In addition, the divalent ion intercalated reduced graphene hydrogel showed good generation after three cycles of simultaneous adsorption.

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水热还原石墨烯水凝胶与二价离子嵌入染料研究

就其对染料污染物的吸附行为而言，仍缺乏涉及二价离子插层石墨烯基水凝胶的基础研究。在这项研究中，我们准备了自组装的Mg ²⁺和Ca ²⁺水热处理的插层还原石墨烯水凝胶（rGH），以评估插层对阳离子染料，亚甲基蓝和若丹明B的吸附能力的影响。使用二价离子插层还原石墨烯水凝胶研究了其形态，结构，热和织构性质傅里叶变换红外光谱仪，热重分析，拉曼光谱，扫描电子显微镜-能量色散光谱，X射线光电子能谱，Brunauer-Emmett-Teller表面积分析和X射线衍射。由于Mg ²⁺和Ca导致比表面积和孔体积的增加，导致二价离子插层的还原型石墨烯基水凝胶对染料分子的吸附能力增强。²⁺桥接在石墨烯片框架之间形成空间。吸附动力学和平衡吸附等温线分别通过伪二级拟合和颗粒内扩散动力学模型以及Langmuir等温线拟合。此外，二价离子插入的还原石墨烯水凝胶在同时吸附的三个循环后显示出良好的生成。