The conventional etching method for exfoliating MXene using hydrofluoric acid solution is time-consuming and inefficient in productivity. A double layer force is generated through polarization among the heterogeneous layers of MXene due to their different dielectric properties. The exfoliated MXene by the polarization method in an acidic solution was employed to synthesize magnetic MXene (MXFe) with FeO nanoparticles. MXFe was coated on polyacrylonitrile microspheres (PANs) as precursors (PAN@MXFe) by Pickering emulsion polymerization. The core@shell polyvinyltetrazole@MXFe (PVT@MXFe) was obtained as the adsorbent after subsequent cyano-tetrazole conversion of PAN@MFs for the removal of toxic metal ions. The maximum adsorption capacities of Hg(II) on the MXFe and PVT@MXFe coating 2 wt% of MXFe were 579 and 324 mg/g, respectively, indicating the high use efficiency of MXFe. At 8.5 kHz of high frequency, hyperthermia occurs on the PVT@MXFe, facilitating the desorption of the toxic metal ions from the adsorbents. Compared with reuse using an acidic solution, the PVT@MXFe can be reused repeatedly 10 times without obvious damage under the AMF. Our proposed polarization exfoliation method not only provides a novel methodology to exfoliate MXene but also develops an ideal adsorbent for universal adsorption, simple separation, stable regeneration, and low secondary pollution.

中文翻译：

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双层力剥离MXene纳米片制备有毒金属离子磁性吸附剂并具有热效应回收

传统的使用氢氟酸溶液蚀刻MXene的方法耗时且生产率低下。由于 MXene 异质层介电特性不同，它们之间的极化会产生双层力。采用酸性溶液中极化法剥离的 MXene 与 Fe3O 纳米粒子合成磁性 MXene (MXFe)。通过 Pickering 乳液聚合将 MXFe 作为前体 (PAN@MXFe) 涂覆在聚丙烯腈微球 (PAN) 上。经过对 PAN@MF 进行氰基四唑转化后，得到核@壳聚乙烯四唑@MXFe（PVT@MXFe）作为吸附剂，用于去除有毒金属离子。 MXFe和PVT@MXFe涂层2 wt% MXFe对Hg(II)的最大吸附容量分别为579和324 mg/g，表明MXFe的高利用率。在 8.5 kHz 高频下，PVT@MXFe 上会发生高温，促进有毒金属离子从吸附剂中解吸。与使用酸性溶液重复使用相比，PVT@MXFe在AMF下可以重复使用10次而没有明显损坏。我们提出的极化剥离方法不仅提供了一种新颖的剥离MXene的方法，而且开发了一种通用吸附、分离简单、稳定再生和低二次污染的理想吸附剂。