High antifouling graphene membranes with Fe2O3 nanoparticles in-situ intercalation for selective dye/salt separation

Effective organic dyes selective separation from high salinity textile wastewater consisting of inorganic salts and organic dyes is of great significant for the textile wastewater treatment. Graphene oxide (GO) have been used widely to form ultrathin high-permeance membrane for molecular and ionic sieving. However, swelling and membrane fouling of GO membrane hampered its practical applications. In this work, high stability and antifouling reduced graphene oxide (rGO) membranes were prepared, and Fe2O3 nanoparticles was used as intercalation to turn the membrane interlayer spacing. The rGO/2Fe2O3 nanocomposite blended membrane exhibited high permeance of 24.90 L m−2 h−1 bar−1, excellent organic dyes rejection (98.15 % and 98.69 % for methylene blue and Evans blue, respectively) and low salt retention (6.26 % for NaCl). Meanwhile, this membrane demonstrated a superior selective dye/salt separation factor up to 232 with a high rejection of 99.59 % to Evans blue and a lower salt rejection of 5.03 % to NaCl. Furthermore, nanofiltration experiments towards Evans blue/NaCl mixed solution indicated that the membrane also exhibited excellent antifouling performance with flux recovery rate of >86 % after six fouling/backwash cycles. Therefore, our work may provide a promising idea for the development of two-dimensional nanofiltration membranes for efficient high salinity textile wastewater treatment.