Synthesis and properties of titania nanofibers by electrospinning method

Titania (TiO2) nanofibers were synthesized by combinations of sol-gel assisted electrospinning and calcination processes. The sol-gel was prepared from titanium (IV) isopropoxide (TIP) and poly (vinylpyrrolidinone) (PVP). The synthesized TiO2 nanofibers were investigated in various ways: thermal stability by thermogravimetric analysis (TGA), fnctional groups by Fourier transform infrared spectroscopy (FTIR), crystalline structures by X-ray diffraction (XRD), and surface morphology by scanning electron microscopy (SEM). The TGA curve revealed that the volatile solvents, organic precursor, and polymer completely removed at approximately 100, 300, and 350-400 C or higher respectively. The as-spun TIP/PVP fibers were smooth surfaced, uniform, and continuous with average diameters of 298-365 nm. The diameter of the nanofibers decreased with increasing calcination temperature. The nanofibers calcined at 600 C and became rough with diameters of 147-284 nm. The phases of TiO2 nanofibers calcined at 500 C were anatase and rutile. After increasing calcination to 600-700 C, the nanofibers became more rutile phase, and above 700 C the nanofibers became rutile phase completely. The FTIR spectra showed absorption bands at 500-700 cm-1 that confirmed the formation of metal-oxide of titania nanofibers.