Flexible, fouling-resistant and self-cleaning Ti3C2Tx-derivated hydrophilic nanofiltration membrane for highly efficient rejection of organic molecules from wastewater

Up to now, the applications of nanofiltration membranes for removal of organic molecules from wastewater have still be restricted due to the improper channel distribution, inherent low chemical stability and easy fouling of the membranes. In this study, a new kind of Ti3C2Tx-deviated hybrid nanomaterial membranes is fabricated by a vacuum-filtration strategy on a cellulose acetate support. Ti3C2Tx nanosheets, together with the self-derivated TiO2, are found to play a key role to establish continuous water transmission channels. With the incorporation of TiO2 nanoparticles, the surface roughness of the prepared membranes also decreases apparently. By this new design, the water flux of the Ti3C2Tx-TiO2 membrane increases to a maximum value of 75.4 L/m2 h bar 4 times higher than that of the pristine Ti3C2Tx membrane, together with a high removal ratio of above 99% for one typical small molecule organic contaminant of rhodamine B (RhB). The composite membranes also exhibit a good anti-fouling performance, since the adsorption tendency of pollutants on the surface of the membrane or the blockage of the pores was decreased. In addition, the excellent photocatalytic self-cleaning ability of the membranes under UV light, with the improved possibility of highly efficient recycling, was also validated, which was ascribed to the in situ formation of Ti3C2Tx/TiO2 heterojunctions. This study provides a new prospective for providing multi-functional nanofiltration membranes in the field of wastewater treatment.