Self-assembled MXene-based nanocomposites via layer-by-layer strategy for elevated adsorption capacities

The chemical modification and organized self-assembly of MXene-based nanocomposites demonstrate critical importance to a wide range of material applications. Herein, we have investigated the preparation of new hierarchical core-shell type MXene-based composite materials for high-efficient dye removal in wastewater treatment via layer-by-layer (LbL) strategy. From the carboxyl functionalization of the MXene material, the negative functional groups were obtained on the surface of the shell composite layer. Carboxyl functionalized MXene materials are immersed in polyimide and polyacrylic acid solution respectively, which leads to formation of shell structure on the surface of MXene layer. Alternating self-assembly processes in the solutions of the polyimide and polyacrylic acid polymers are investigated until the desired number of shell layers is fabricated around MXene layer structures. Finally, the core-shell nanocomposites were characterized by morphological and spectral techniques, demonstrating that the core-shell nanocomposites have more reaction sites and mesoporous structures. The as-obtained core-shell nanocomposites were evaluated with well adsorption capacities via three kinds of dyes. Thus the study of MXene based composites assembled by LbL provides a new choice for the application of MXene composite nanomaterials in wastewater treatment.