Effect of Hydrogen Reduction on the Optical and Giant Dielectric Properties of (La/Ni) Merge Co-doped Rutile TiO2 Nanoparticles

Abstract Pure and lanthanum/nickel merge co-doped rutile (R) titanium dioxide (TiO2) nanoparticles (NPs) were synthesized by a method of hydrothermal decomposition followed by high-temperature calcination. The synthesized NP ceramic passed standard characterization methods including X-ray diffraction for structural analysis, diffuse reflectance spectroscopy for optical properties investigation, and dielectric measurements for insulating properties study. The present investigation aims to synthesize giant dielectric permittivity medium from rutile TiO2 NPs by using the doping phenomenon to build up distinct potential barriers at crystallite boundaries that build core/shell electronic construction. The RT dielectric permittivity (ε′) obtained in this work was 1.56 × 103 at 1 kHz, whereas the known dielectric permittivity of TiO2(R) powder was 185 at RT. Moreover, it was observed that the hydrogenation reduced the value of ε′ to 0.694 × 103. Therefore, with the present co-doping, the dielectric permittivity of the rutile TiO2 strongly increased (by ∼8.5 times) compared to pure rutile TiO2. The results of this work were explained using the available suitable models.