Lim Chuan Chuan, Shuit Siew Hoong, Ng Qi Hwa, Rahim Siti Kartini Enche Ab, Hoo Peng Yong, Yeoh Wei Ming, Goh Soon Wah
Faculty of Chemical Engineering & Technology, Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia.
Department of Chemical Engineering, Lee Kong Chian Faculty of Engineering & Science, Universiti Tunku Abdul Rahman, Sungai Long Campus, Jalan Sungai Long, Bandar Sungai Long, Cheras, 43000, Kajang, Selangor, Malaysia.
Environ Sci Pollut Res Int. 2023 Mar;30(14):40242-40259. doi: 10.1007/s11356-022-25064-4. Epub 2023 Jan 6.
In view of the simple and rapid conveniency of magnetic separation, magnetic nanocomposites had notably gained attention from researchers for environmental field applications. In this work, carboxylated magnetic multi-walled carbon nanotubes (c-MMWCNTs) and novel sulfonated MMWCNTs (s-MMWCNTs) were synthesized by a facile solvent-free direct doping method. Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscope, energy dispersive X-ray, vibrating sample magnetometer, and point of zero charge analyses confirmed the successful doping of the FeO nanoparticles into the functionalized MWCNTs to form MMWCNTs. Besides, the bonding stabilities of both c-MMWCNTs and s-MMWCNTs were compared, and results showed that s-MMWCNTs possessed more substantial bonding stability than that of c-MMWCNTs with significantly less leaching amount of FeO. The adsorption capacity of s-MMWCNTs was higher than that of c-MMWCNTs owing to the stronger electronegativity sulfonic group in s-MMWCNTs. Moreover, the reusability experiments proved that the adsorbent remained consistently excellent MB removal efficiency (R > 94%) even reused for twelve cycles of batch adsorption. The finding of the present work highlights the simple fabrication of novel s-MMWCNTs and its potential to be served as a promising and sustainable adsorbent for water remediation owing to its enhanced bonding stability, high adsorption performance, magnetic separability, and supreme recyclability.
鉴于磁分离操作简单、快速便捷，磁性纳米复合材料在环境领域的应用备受研究人员关注。在本工作中，通过一种简便的无溶剂直接掺杂法合成了羧基化磁性多壁碳纳米管（c-MMWCNTs）和新型磺化多壁碳纳米管（s-MMWCNTs）。傅里叶变换红外光谱、X射线衍射、扫描电子显微镜、能量色散X射线、振动样品磁强计和零电荷点分析证实了FeO纳米颗粒成功掺杂到功能化多壁碳纳米管中形成了MMWCNTs。此外，比较了c-MMWCNTs和s-MMWCNTs的键合稳定性，结果表明s-MMWCNTs具有比c-MMWCNTs更稳定的键合，且FeO的浸出量显著减少。由于s-MMWCNTs中磺酸基团的电负性更强，其吸附能力高于c-MMWCNTs。此外，可重复使用性实验证明，即使在分批吸附中重复使用12个循环，该吸附剂仍能始终保持优异的亚甲基蓝去除效率（R>94%）。本工作的发现突出了新型s-MMWCNTs的简便制备方法，以及因其增强的键合稳定性、高吸附性能、磁分离性和卓越的可回收性而有望成为一种可持续的水修复吸附剂的潜力。
