Preparation of TiO₂ Nanofibrous Membranes with Hierarchical Porosity for Efficient Photocatalytic Degradation

In order to solve the complex spinneret and unstable structure of multifludic electrospinning and side-by-side electrospinning, TiO₂ nanofibers with hierarchical porosity were fabricated via microemulsion electrospinning, which can be realized just by single-spinneret electrospinning. The morphology, crystal, and specific surface area of the TiO₂ nanofibers were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and physisorption analyzer. The photocatalytic activities of TiO₂ nanofibers calcined at 500, 700, and 900 °C were examined. The experimental results indicated that TiO₂ nanofibers were hollow, and the wall of nanofibers possessed abundant mesopores. The specific surface area of TiO₂ nanofibers calcined at 500 °C was approximately 41.4 m²/g, which was favorable for increasing the photocatalytic reaction sites and the separation efficiency of electron–holes. The photocatalytic results demonstrated that compared with solid TiO₂ nanofibers, the photocatalytic activities of the TiO₂ nanofibers prepared via microemulsion electrospinning were significantly enhanced. Particularly, the TiO₂ nanofibers calcined at 500 °C could decompose methyl blue (MB) solution completely within 70 min. The results verified that microemulsion electrospinning was indeed a simple, versatile, and convenient method to prepare porous inorganic nanofibers for various applications