Nano TiO2 was prepared by conventional and micelle – tempelate method using Triton-x-100 surfactant. The synthesized materials were characterized by X-ray diffraction, FT-IR, thermal analysis, Electron microscopy (SEM) as well as (TEM). The results showed a particle size with different morphologies in the range of 5-27 nm. The influence of the synthesis parameters on the phase structure, morphological surface and electrical properties (ac- and dc-electrical conductivity, impedance, dielectric constant and dielectric loss) as well as biological activity was investigated. The obtained results are correlated and discussed. Rutile structure is found to be formed at lower temperatures, whereas the anatase structure formed and become more stable at higher temperatures. All the prepared samples exhibited high surface areas and pore volumes that are related to the lower particle sizes of the samples. The temperature dependence of the electrical conductivity for the investigated samples showed semiconductor behavior. The electrical conduction process was explained according to the correlated barrier hopping mechanism (CBH). The impedance spectra for the samples investigated showed a single semicircle that acts as a parallel combination of capacitor and resistance. The effect of particle size and morphology on electrical properties (electrical conductivity (σ), dielectric constant (ε`) and dielectric loss (ε``), surface properties, photocatalytic activity, dye/TiO2 solar cell efficiency and biological activity has been discussed. The results showed a tuning in the energy gap with the decrease in the particle size. All the prepared samples showed higher photocatalytic degradation for organic materials such as methylene blue. Dye synthesized solar cells are fabricated using the prepared nano TiO2 samples. The results showed solar cell with high efficiency of ~6%. The prepared nano TiO2 with anatase structure showed higher biological activity toward E. Coli. While the sample prepared using Triton-X 100 surfactant that has rutile structure showed higher biological activity toward Ser. M. and Agr. S. |
