Influences of acids on morphology and properties of TiO2 grown on electrospun PVDF fibers

Abstract

TiO2 with different crystalline phases and morphologies was grown on poly(vinylidene fluoride) (PVDF) fibers through electrospinning followed by hydrothermal synthesis in different acidic environments. The structural and morphological characteristics of the as-prepared composites were studied. The results show that the type and the concentration of the acids have a decisive influence on the crystalline phase, morphology, and loading mass of the TiO2 grown on the PVDF fiber. The formation of anatase TiO2 is favored in the hydrothermal environment of H2SO4 and CH3COOH, whereas rutile TiO2 is more readily obtained in HCl and HNO3. The morphology and the mass of the grown TiO2 undergo a significant change with increasing acid concentration. Four samples were selected from the TiO2/PVDF composites hydrothermally synthesized in H2SO4, HNO3, HCl, or CH3COOH to perform photocatalytic degradation of rhodamine B under 40 W UV lamp irradiation for 120 min. The TiO2/PVDF sample hydrothermally synthesized in H2SO4 showed the highest photodegradation efficiency (about 63.2%) owing to its excellent optical performance, the highest TiO2 loading mass, and the lowest photogenerated electron-hole recombination rate.