Enhancement of Dielectric Responses and Conduction Properties of Zn-doped TiO2 for Energy Storage and Photosensitivity Applications

Abstract This work deals with the physical investigations on Zn-doped TiO2 synthesized via a solvent controlled non-aqueous sol–gel route. X-ray diffraction analysis indicated that TiO2 particles crystallized in both tetragonal anatase and rutile structures. FTIR analysis confirmed the insertion of Zn in TiO2 network, and revealed the presence of surface defects in the prepared powders, as proved by their porous morphologies. UV-visible absorption was performed to provide an insight into the band-gap variation in the Zn-doped TiO2 nanopowders as a function of Zn doping. On the other hand, the electrical properties were studied using complex impedance spectroscopy in the frequency range from 40Hz to 1MHz at temperature range 480-600K. The impedance plots are well fitted to an (R1//C1)-(R2//CPE1) equivalent circuit. As well, the correlated barrier hopping model (CBH) was proposed to describe the conduction mechanism. Finally, Photocatalytic activities of the Zn doped TiO2 nanoparticles were evaluated via the degradation of the rhodamine B (RhB) dye under UV light irradiation. The results showed enhanced performance by Zn-doping, compared to the undoped TiO2 nanoparticles.