Titanium oxide nanotubes intercalated two-dimensional MXene composite membrane with exceptional antifouling and self-cleaning properties for oil/water separation

The utilization of two-dimensional (2D) MXene-based membranes represents a promising approach for the treatment of oily wastewater. Nevertheless, the long and narrow flow channels between MXene interlayers pose a significant obstacle to achieving an excellent permeability and retention. Herein, titanium oxide nanotubes (TiONT) with an exceptional aspect ratio and performance were inserted into the interlayer space of 2D MXene-based membrane. The prepared polyethersulfone supported MXene/TiONT (PMT) membrane has excellent hydrophilicity with a water contact angle decreasing from 36.5° to 0°, retention rates of emulsions higher than 99.7% and an ultra-high permeability of 578.7 L·m−2·h−1·bar−1. The PMT membrane has excellent antifouling and self-cleaning properties, and the flux recovery rate can reach 83% of bovine serum albumin and 100% of humic acid as foulants under visible light irradiation. In addition, based on extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory, the incorporation of TiONT increased the interaction energy between PMT membrane and pollutants, thus improving antifouling performance. Overall, this novel 2D membrane holds great promise for large-scale continuous separations of oil/water emulsions.