Self-cleaning SiO₂–TiO₂ ceramic membrane for enhanced oil–water separation

An efficient and practical method is proposed for the separation of oil–water mixtures and emulsions in sustainable water ecosystems, facilitating energy recovery. The construction of flexible ceramic fiber membranes with high throughput and self-cleaning capabilities has proven effective but challenging. This study reports a novel approach combining the sol–gel and electrospinning techniques to synthesize flexible silicon dioxide (SiO₂)–titanium dioxide (TiO₂) nanofiber membranes (STNFMs). These membranes possess nanoscale rough structures, granting them superhydrophilicity and underwater superoleophobicity (155°). Exploiting the photocatalytic properties of titanium dioxide, STNFMs-4 not only demonstrates excellent separation performance but also exhibits remarkable self-cleaning abilities. After 2 h of ultraviolet light irradiation, the membrane flux returns to its original level. STNFMs provide a promising solution for highly efficient separation of oil–water mixtures and emulsions, with the potential to play a significant role in water treatment and resource recovery.