Abstract
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•The effect of ultrasonication and gelatin addition on TiO2@ZnO nanocomposites was reconnoitered.•The analysis revealed titanium rutile phase formation and band gap widening were observed.•The electrical investigation exhibited conductivity drop and grain boundary resistance effects of TiO2 doping.
Herein, TiO2@ZnO nanocomposites were prepared via ultra-sonication using gelatin as a stabilizing agent. The structural characterization revealed the development of a rutile TiO2 phase that monotonically increased with TiO2 loading as confirmed by the Raman active modes. The micrographs indicated reduced size spherical structures endorsing the XRD 43 – 37 nm crystallite sizes and the EDS data ascertained the inclusion of Zn, Ti, and O in the nanocomposites. A Burstein-Moss band gap widening effect from 3.196 eV for pure ZnO to 3.237 eV was exhibited by the highest TiO2 content. A decrease in dielectric constant and ac conductivity (from 4.12 × 10−4 Ω−1.cm−1 for bare ZnO to 1.41 × 10−4 Ω−1.cm−1 for highest doped sample) as a function of frequency and TiO2 loading. The Nyquist plot exhibited single semicircle arcs and increased bulk resistance from 0.025 to 3.00 × 107 Ω due to doping connoting the prevalence of grain boundary resistance.