Facile synthesis of 2D TiO2@MXene composite membrane with enhanced separation and antifouling performance

While composite membranes with two-dimensional (2D) lamellar materials (e.g., graphene and MXene) have recently attracted increasing attention, fabrication of high-performance 2D membrane still faces a serious challenge. In this study, 2D TiO2@MXene nanomaterial was prepared and introduced to fabricate polyethersulfone (PES)-TiO2@MXene composite membrane. The composite membrane displayed superior separation and antifouling performance. When filtrating 1.0 g L-1 bovine serum albumin (BSA) solution, the flux of the optimal membrane (BSA rejection 95%) reached to 756.8 L m- 2 h- 1.bar- 1, which is 185% higher than that of the original membrane (BSA rejection 70%). Moreover, the PES-TiO2@MXene composite membrane possessed excellent self-cleaning function under UV irradiation, which was verified by the flux recovery rate (FRR) values of 80.2%, 100%, 100% and 99.56% for BSA, sodium alginate (SA), humic acid (HA) and yeast (YE) solution, respectively. The excellent self-cleaning ability can be put down to the special 2D TiO2@MXene structure where there exists a synergy between MXene and TiO2 for self-cleaning. The composite membrane demonstrated a significant superiority in filtration performance over those in the literature. According to extended DerjaguinLandau-Verwey-Overbeek (XDLVO) approach, the PES-TiO2@MXene composite membrane displayed an optimal interface condition, significantly reducing the attractive interactions with foulants. The facile fabrication method, together with the efficient membrane performance, indicated good application prospects of the PESTiO2@MXene composite membrane proposed in this study.