Alignment of MXene based membranes to enhance water purification

Abstract

Membrane-based separation techniques are crucial for mitigating the pollution of aquatic environments and addressing challenges associated with water scarcity. Controlling the structure and chemical functionality of two-dimensional materials can enable the development of new classes of membranes that overcome the limitations of conventional membrane materials to optimize water purification performance. This work uses supramolecular cyclodextrins to decorate the exterior surface of MXene materials, thereby fabricating a series of hybrid membranes via vacuum-assisted self-assembly. These novel nanofiltration membranes can be used to efficiently separate dyes from wastewater. Compared with pristine MXene membranes, the permeability flux of the best-performing membrane increased 23.3 times, while its rejection of methylene blue exceeded 99.7%, most likely because of charge effects and size-selective molecular sieving features of the membranes. This study offers a promising approach for developing advanced membrane separation technologies for water purification by precisely controlling the two-dimensional membrane structure using supramolecular chemistry.