College of Metallurgy and Material Engineering, Hunan University of Technology, Zhuzhou 412007, P. R. China.
College of Chemistry, Xiangtan University, Xiangtan 411105, P. R. China.
J Nanosci Nanotechnol. 2020 Mar 1;20(3):1814-1821. doi: 10.1166/jnn.2020.17357.
Graphene-oxide-wrapped magnetic Fe₃O₄ nanocluster (NC) composites (MC@GO) were prepared and their characteristics were analyzed by multiple characterization methods. Results indicated that the magnetic NCs (~400 nm in size) were composed of numerous Fe₃O₄ monocrystalline particles (30-50 nm in size) and MC@GO had stable structure, high saturation magnetization (61 emu/g) and specific surface area of 112.5 m²/g. The magnetic NCs were integrally and tightly encapsulated in the composites by silk-like GO sheets via electrostatic interaction. The formation mechanism for MC@GO is also discussed in detail herein. Fe was reduced by ethylene glycol in the adopted synthesis scheme, to generate Fe₃O₄ monocrystalline particles that aggregated to form Fe₃O₄ NCs with rough surfaces. Subsequent SiO2 coating and positive charge introduction caused the GO sheets to firmly wrap around the magnetic NCs, resulting in novel GO wrapped magnetic NC composites. The Fe₃O₄ NCs contributed much to structure amelioration and performance enhancement of the final GO composites. The rough surfaces of Fe₃O₄ NCs were beneficial for the SiO2 coating and final wrapping of GO sheets. The good magnetic property and beneficial structure of MC@GO make it an ideal adsorbent, which was demonstrated in the current study using methylene blue (MB) as a model adsorbate. The maximum MB adsorption capacity for MC@GO reached 105.5 mg/g. This is the first study on GO-wrapped Fe₃O₄ NC composites and their potential use for environmental adsorption. Furthermore, this study provides a method for developing GO wrapped magnetic particle composites by tailoring the magnetic precursor.
氧化石墨烯包裹的磁性 Fe₃O₄ 纳米团簇（NC）复合材料（MC@GO）被制备出来，并通过多种表征方法对其特性进行了分析。结果表明，磁性 NCs（大小约为 400nm）由许多 Fe₃O₄ 单晶体颗粒（大小 30-50nm）组成，MC@GO 具有稳定的结构、高饱和磁化强度（61emu/g）和 112.5m²/g 的比表面积。磁性 NCs 通过丝般的 GO 片通过静电相互作用整体而紧密地包裹在复合材料中。本文还详细讨论了 MC@GO 的形成机制。在采用的合成方案中，乙二醇还原 Fe 生成 Fe₃O₄ 单晶体颗粒，这些颗粒聚集形成具有粗糙表面的 Fe₃O₄ NCs。随后进行 SiO2 涂层和正电荷引入，使 GO 片牢固地包裹在磁性 NCs 周围，从而形成新型的 GO 包裹磁性 NC 复合材料。Fe₃O₄ NCs 对最终 GO 复合材料的结构改善和性能提高有很大的贡献。Fe₃O₄ NCs 的粗糙表面有利于 SiO2 涂层和最终的 GO 片包裹。MC@GO 的良好磁性和有益结构使其成为一种理想的吸附剂，本研究以亚甲基蓝（MB）为模型吸附质对此进行了验证。MC@GO 对 MB 的最大吸附容量达到 105.5mg/g。这是首次对 GO 包裹的 Fe₃O₄ NC 复合材料及其在环境吸附中的潜在应用进行研究。此外，本研究通过调整磁性前体为开发 GO 包裹磁性颗粒复合材料提供了一种方法。
