Shahzad Asif, Rasool Kashif, Iqbal Jibran, Jang Jiseon, Lim Youngsu, Kim Bolam, Oh Jae-Min, Lee Dae Sung
Department of Energy and Materials Engineering, Dongguk University, Seoul, 04620, Republic of Korea.
Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5824, Doha, Qatar.
Environ Res. 2022 Apr 1;205:112532. doi: 10.1016/j.envres.2021.112532. Epub 2021 Dec 9.
Two-dimensional (2D) transition metal carbides and nitrides (MXenes) have drawn considerable attention for application in the field of environmental remediation. In this study, we report the simultaneous reductive-adsorption behavior of TiCNT for toxic metal ion Hg ion in the aqueous phase. 2D TiCNT and TiCT MXene nanosheets were synthesized by exfoliation of TiAlCN and TiAlC MAX phases, respectively. Various characteristics analysis confirmed the successful fabrication of MAX phases and their exfoliation into MXenes. The fabricated MXene nanosheets were used to investigate their Hg removal, Hg intercalation, and surface interaction mechanism efficiencies. Both MXenes were found to adsorb and reduce a large amount of Hg. Analytical techniques such as X-ray powder diffraction, field emission transmission electron microscopy, zeta-potential analyses, and X-ray photoelectron spectroscopy were used to investigate the material characteristics and structural changes after uptake of Hg. The quantitative investigation confirmed the interaction of bimetal and hydroxyl groups with Hg using electrostatic interactions and adsorption-coupled reduction. In addition, both MXenes exhibited extraordinary Hg ion removal capabilities in terms of fast kinetics with an excellent distribution coefficient (K) up to 1.36 × 10. Based on batch adsorption results, TiCT and TiCNT exhibited removal capacities of 5473.13 and 4606.04 mg/g, respectively, for Hg, which are higher than those of previous Hg adsorbents.
二维（2D）过渡金属碳化物和氮化物（MXenes）在环境修复领域的应用引起了广泛关注。在本研究中，我们报道了TiCNT在水相中对有毒金属离子汞离子的同时还原吸附行为。二维TiCNT和TiCT MXene纳米片分别通过剥落TiAlCN和TiAlC MAX相合成。各种特性分析证实了MAX相的成功制备及其剥落成MXenes。制备的MXene纳米片用于研究其汞去除、汞嵌入和表面相互作用机制效率。发现两种MXenes都能吸附和还原大量汞。使用X射线粉末衍射、场发射透射电子显微镜、zeta电位分析和X射线光电子能谱等分析技术来研究汞吸附后材料的特性和结构变化。定量研究证实了双金属和羟基通过静电相互作用和吸附耦合还原与汞的相互作用。此外，两种MXenes在快速动力学方面均表现出非凡的汞离子去除能力，具有高达1.36×10的优异分配系数（K）。基于批量吸附结果，TiCT和TiCNT对汞的去除容量分别为5473.13和4606.04 mg/g，高于先前的汞吸附剂。
