Unveiling temperature-modified electrospun TiO2 nanofibers with size-driven microstructure evolution and enhanced photocatalytic effect

Tailoring the properties and functionalities of TiO2 nanofibers (NFs) via controlling the surface morphology, size, and compositions has attracted tremendous attention in the last few decades. Nevertheless, the development of an efficient and stable nanostructured TiO2 NFs photocatalyst remains a challenge. Here, a heat treatment temperature-driven appearance on the microstructural evolution of TiO2 NFs and the corresponding impact on the photodegradation of organic dye were reported based on the precursor decomposition, crystallization, surface structure and active radicals. Systematic TG/DSC curves, IR spectra, X-ray diffraction, SEM and TEM images, XPS and PL spectra illustrated the impact of temperature on thermal decomposition, microstructure, morphologies and surface structure. Anatase TiO2 NFs at 900 °C with better morphological thermal stability, crystallite size and crystallinity possessed highest photocatalytic activities due to low electron-hole recombination and high production of •OH and O2•-. With the addition of radical scavengers, the results illustrated O2•- and •OH acted as the main radicals on the process of photocatalytic activities. The results of this work may provide valuable information to design and produce new highly efficient TiO2 NFs materials for wastewater treatment applications. •As a result of thermal analysis, the TiO2 NFs showed good phase and structural thermal stability.•Without the presence of rutile, anatase TiO2 NFs with better crystallite size and crystallinity possessed highest photocatalytic activities.•Based on catalytic mechanism exploration, effects of different parameters on photocatalytic activity were investigated.