In situ synthesis of flexible hierarchical TiO2 nanofibrous membranes with enhanced photocatalytic activity

Abstract

Construction of nanoparticle modified titanium dioxide nanofibrous membranes (TiNFs) with a mesoporous and stable nanoparticle-nanofiber composite structure would have significant implication for environmental remediation; however, currently nanoparticle-TiNFs are generally brittle with poor structural integrity upon large deformation; thus, creating flexible, robust, and stable nanoparticle-TiNF composites has proven to be extremely challenging. Herein, we report flexible and hierarchical mesoporous TiO₂ nanoparticle (TiO₂ NP) modified TiNF (TiNFNPs) composites fabricated by the combination of sol–gel electrospinning and in situ polymerization. The electrospun TiNFs served as templates and a synthesized bifunctional benzoxazine (BA-a) was used as a novel carrier and fixative for non-agglomerated growth of TiO₂ NPs. Benefiting from the large surface area, high porosity, homogeneity, stable nanofiber–nanoparticle composite structure, and robust mechanical properties, the as-prepared anatase TiNFNPs exhibited excellent photocatalytic activity towards methylene blue including fast degradation within 30 min, good reversibility in 4 cycles, and easiness of recycling. Moreover, the degradation products have been analysed and TiNFNPs exhibited better photodegradation performance towards methylene blue compared with a commercial catalyst (P25). Significantly, the successful synthesis of such fascinating materials may provide a versatile platform for further development of nanofibrous membrane-based photoreactors towards water and air pollutant treatment.