Investigation of structural, electronic and optical properties of pure and Ag-doped TiO2 nanofibers fabricated by electrospinning

Pure and 1, 2, and 3 wt% Ag doped TiO2 nanofibers were prepared by electrospinning method at different applied voltages and heights at a constant flow rate of 2 mL/h. Characterization of the prepared samples was performed by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microcopy (AFM),four point probe method (FPPM), the differential scanning calorimetry/the thermal gravimetric analysis (DSC/TGA), ultraviolet/visible spectrometry (UV/VIS), and energy dispersive X-ray spectrometer (EDX). It was found that the thermally untreated pure TiO2 nanofibers and thermally treated (at 500 degrees C) samples have the crystalline phase of anatase (A), and mixed anatase and rutile (A+R) phases, respectively. It was also observed that the content of the silver does not affect the crystal structure, but plays strengthening role in the rutile structure. SEM micrographs showed that all fabricated nanofiber samples have uniform morphologies, and AFM measurements indicated that the nanofibers were formed in three-dimensional coils. The band gap values of the nanofiber samples obtained from UV/VIS measurements revealed that band gap values of the nanofiber samples decrease while the diameter of the nanofiber increases.