Fabrication and characterization of TiO2–ZnO composite nanofibers

Tetraisopropyl titanate, zinc acetate dihydrate, and polyvinylpyrrolidone (PVP) were mixed to obtain a composite solution for producing TiO2–ZnO nanofibers. Electrospinning and subsequent calcination at 973 K were employed to produce composite metal-oxide nanofibers with diameters ranging from 50 to 150 nm. Characterization of the TiO2–ZnO composite nanofibers was carried out by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (XEDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), and ultraviolet–visible (UV–vis) spectrophotometry. TGA reveals a total weight loss of 49% and no change in mass above 873 K. The nanofibers are predominantly made of titania and exhibit two different energy band gap values of 3.0 and 3.5 eV. Our findings indicate that in the composite TiO2–ZnO nanofibers three different phases (anatase and rutile TiO2 and wurtzite ZnO) can co-exist and retain their individual characteristic properties.

Research Highlights
► TiO2–ZnO composite nanofibers with diameters ranging from 50 to 100 nm are produced using an electrospinning method.
► Electron microscopy revealed dispersion of nanoparticles along the surface of the nanofibers.
► ZnO crystals favor the surface region of the nanofibers.
► Anatase (A) and rutile (R) TiO2 phases, together with the wurtzite ZnO structure, are observed.
► Band gap energies of the composite nanofibers were 3.0 and 3.5 eV.