Abstract Graphene oxide (GO) is an excellently conductive carbon material composed of versatile building blocks that can self-assemble a broad range of nanoparticles, and the features of GO can be tuned to accommodate various self-assembly approaches. Using the benefits of a simple self-assembly of two oppositely charged nanomaterials via electrostatic interactions, GO and MgFe2O4 can be self-assembled together, and the assembled composites are expected to possess special properties as catalysts in comparison to their individual counterparts. In this research, novel magnetic separable MgFe2O4/crumbled reduced GO (rGO) nanoparticles of surface area 35 m2/g and adsorption capacity 24.81 mg/g were synthesized to eliminate methylene blue (MB) dye as a primary cationic organic dye pollutant model. The physicochemical features were explored using field emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and N2-adsorption/desorption isotherms. The rod-like structured of the as-synthesized nanoparticles with crystallite size of 11 nm were deposited homogeneously on the surface of wrinkles of rGO with a crumbled sheet structure. The microstructure analysis indicated the accumulation of MgFe2O4 on the wrinkles and the edges, rather than the basal planes, due to the distribution of the COOH groups on the GO. The influences of catalyst dose, dye concentration, pH, rate of agitation, and the change in temperature during the dye removal process were investigated. The elimination of MB followed a pseudo second-order reaction and was characterized by multi-layer formation on the solid surface. The values of enthalpy and entropy change were 61 and 0.219 kJ/mol, respectively, indicating a strong interaction between dye molecules and solid surface and the enhancement of the random arrangement of dye molecules on the adsorbent surface. The novel magnetic and easily separable nanoparticles retained 75% of their reactivity on dye removal after four consecutive cycles. The prepared magnetic rGO will allow the synthesis of highly effective and low-cost nanoparticles for dye removal from aqueous solution.

中文翻译：

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用于从水溶液中去除亚甲蓝染料的磁性可分离和可回收粉碎的 MgFe2O4/还原氧化石墨烯纳米粒子的合成和表征

摘要 氧化石墨烯 (GO) 是一种导电性极佳的碳材料，由多功能结构单元组成，可以自组装各种纳米颗粒，并且可以调整 GO 的特性以适应各种自组装方法。利用两种带相反电荷的纳米材料通过静电相互作用进行简单自组装的好处，GO 和 MgFe2O4 可以自组装在一起，并且与单独的对应物相比，组装的复合材料有望具有作为催化剂的特殊性能。在这项研究中，合成了表面积为 35 m2/g 和吸附容量为 24.81 mg/g 的新型磁性可分离 MgFe2O4/粉碎的还原氧化石墨 (rGO) 纳米颗粒，以消除作为主要阳离子有机染料污染物模型的亚甲蓝 (MB) 染料。使用场发射扫描电子显微镜、高分辨率透射电子显微镜、X 射线衍射、X 射线光电子能谱和 N2 吸附/解吸等温线探索物理化学特征。具有 11 nm 晶粒尺寸的合成纳米颗粒的棒状结构均匀沉积在具有破碎片状结构的 rGO 皱纹表面。微观结构分析表明，由于 COOH 基团在 GO 上的分布，MgFe2O4 在皱纹和边缘而不是基面上积累。研究了催化剂用量、染料浓度、pH 值、搅拌速率和染料去除过程中温度变化的影响。MB 的消除遵循伪二级反应，其特征是在固体表面形成多层。焓值和熵变值分别为 61 和 0.219 kJ/mol，表明染料分子与固体表面相互作用强，染料分子在吸附剂表面的随机排列增强。新型磁性且易于分离的纳米粒子在连续四个循环后保留了 75% 的染料去除反应性。制备的磁性 rGO 将允许合成高效和低成本的纳米粒子，用于从水溶液中去除染料。表明染料分子与固体表面之间有很强的相互作用，并增强了吸附剂表面染料分子的随机排列。新型磁性且易于分离的纳米粒子在连续四个循环后保留了 75% 的染料去除反应性。制备的磁性 rGO 将允许合成高效和低成本的纳米粒子，用于从水溶液中去除染料。表明染料分子与固体表面之间有很强的相互作用，并增强了吸附剂表面染料分子的随机排列。新型磁性且易于分离的纳米粒子在连续四个循环后保留了 75% 的染料去除反应性。制备的磁性 rGO 将允许合成高效和低成本的纳米粒子，用于从水溶液中去除染料。