Hu Wenjihao, Xie Lei, Zeng Hongbo
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
J Colloid Interface Sci. 2020 May 15;568:36-45. doi: 10.1016/j.jcis.2020.02.028. Epub 2020 Feb 10.
Energy-efficient process for water desalination and organic dye separation is urgently needed to meet the dramatically increasing demand for fresh water globally. NbCT MXene, as one type of 2D transition metal carbides (TMDCs) family, has attracted tremendous research interest in the fields of separation technology over the past decade. However, it has been challenging to fabricate surface-modified NbCT MXene nanosheet films with superior performance for desalination and separation applications. Herein, we report a novel, facile and scalable sodium alginate (SA)-assisted surface termination method to fabricate SA-modified NbCT MXene (NbSA) nanosheets. It is found that films of the NbSA nanosheets demonstrate overall better performance than bare NbCT MXene nanosheet film. The NbSA film with a thickness of 5 µm shows >95% rejection towards various cations under forward osmosis process. The film also shows a fast water flux of 2200 ± 100 L m h bar (LMHB) with almost 100% rejection rate towards multiple dyes under vacuum-driven filtration mode. Moreover, the NbSA film has exhibited selective separation performance on Li/Mg mixture solution under forward osmosis process. This work reports a novel NbSA film with excellent performances for desalination and separation, with useful implications for developing 2D material films in separation processes and environmental engineering.
为满足全球对淡水急剧增长的需求，迫切需要一种节能的海水淡化和有机染料分离工艺。作为二维过渡金属碳化物（TMDCs）家族的一种，NbCT MXene在过去十年中在分离技术领域引起了极大的研究兴趣。然而，制备具有优异性能用于海水淡化和分离应用的表面改性NbCT MXene纳米片薄膜一直具有挑战性。在此，我们报道了一种新颖、简便且可扩展的海藻酸钠（SA）辅助表面终止方法来制备SA改性的NbCT MXene（NbSA）纳米片。发现NbSA纳米片薄膜总体表现优于裸露的NbCT MXene纳米片薄膜。厚度为5 µm的NbSA薄膜在正向渗透过程中对各种阳离子的截留率>95%。该薄膜在真空驱动过滤模式下还显示出2200±100 L m h bar（LMHB）的快速水通量，对多种染料的截留率几乎为100%。此外，NbSA薄膜在正向渗透过程中对Li/Mg混合溶液表现出选择性分离性能。这项工作报道了一种具有优异海水淡化和分离性能的新型NbSA薄膜，对在分离过程和环境工程中开发二维材料薄膜具有重要意义。
