Sacrificial graphene oxide interlayer for highly permeable ceramic thin film composite membranes

In this study, we report a facile and straightforward graphene oxide pre-coating method to prepare defect-free, ultrathin film composite ceramic hollow fiber membranes. By coating a graphene oxide (GO) interlayer, the defect-free thin alumina active layer with sub-micrometer thicknesses was successfully coated on highly porous substrates without thick interlayers. The GO interlayer not only prevents the pore-clogging of the substrate by boehmite nanoparticles but also helps the thin and uniform formation of active layers. Since the ultrathin GO interlayer was naturally removed during the calcination process of the active layer over 400 °C, the ceramic thin-film composite (TFC) membranes with controllable active layer thickness and pore size were obtained. Prepared ceramic TFC membranes showed outstanding separation performance, which was 2–8 times higher water flux at the same MWCO, compared to commercial multilayered ceramic ultrafiltration membranes. The results demonstrate the superior separation properties of ceramic TFC membranes, and the potential of cost-effective GO interlayer pre-coating methods for fabricating inorganic based membranes for various molecular separation applications.