Graphene Oxide Intercalated with MXene as Composite Membranes with Improved Permeability for Wastewater Treatment

Graphene oxide (GO)-based membranes have exhibited fascinating superiority in water treatment. However, water transfer resistance caused by the tortuous interlayer pathway and swelling in aqueous solutions of GO membranes are still bottlenecks in wastewater treatment. Here, a heterostructured GO membrane was designed by intercalating amino-terminated MXene (MXene-NH2) in GO layers. Specifically, the inserted MXene-NH2 with a small size in the gap of GO layers can increase the vertical distance between GO layers and offer a shortened water transport pathway for enhanced permeability. Meanwhile, the interaction between the amino groups of MXene-NH2 and the carboxyl groups of GO can restrict the deformation of the layered structure, thus inducing improved stability. Accordingly, the obtained GO/MXene-NH2 composite membrane exhibited a flux of about 11.31 L/(m2 h bar) at low pressure (1 bar), which was 4 times higher than that of the GO membrane (̃2.73 L/(m2 h bar)). Meanwhile, high rejections of the membrane for different charged dyes (≥96%) remained. Besides, the GO/MXene-NH2 membrane showed excellent antiswelling properties. This strategy provides a method for the design of a heterostructure membrane and promotes the practical application of the GO membrane.