TiO2 thin films and Ag/TiO2 nanoparticles were prepared by CVD and plasma bombardment method. XRD results showed the presence of Ag nanoparticles in TiO2 matrix. SEM image confirmed formation of Ag nanoparticles. XPS analysis was utilized to study the chemical state of the Ag/TiO2 nanostructure. Statistical surface analysis revealed that since there is a linear relation between logarithmic diagram of Cq(r) and r<Rc~4 mm for all q, both surfaces have self-affine structure. Formation of Ag/TiO2 nanoparticles led to the reduction of roughness of the samples from 0.72 nm to 0.61 nm. Ag/TiO2 nanoparticles represented greater hydrophilicity under UV illumination and visible light compared with TiO2. TiO2 thin films and Ag/TiO2 nanoparticles showed an inhibition for proliferation of the bacteria on their surfaces. Antibacterial activity of the samples contributed to the growth inhibition of the bacteria on their surfaces.

Effect of aging on the properties of titanium dioxide nanoparticles produced by laser ablation process in water is investigated experimentally. The fundamental wavelength of a Q-switched Nd: YAG laser was employed to irradiate a high-purity Ti plate in distilled water at temperatures of 20, 35, 50 and 65oC. Produced nanoparticles were diagnosed by UV–Vis–NIR spectroscopy, X-ray diffraction method, and dynamic light scattering device immediately after production and 1 week after. Bandgap energy of samples was extracted using Tauc method. Size of nanoparticles was increased after a week and their bandgap energy was decreased. Results show that the phase of TiO2 nanoparticles was transited from brookite to rutile after 1 week.

Nowadays, the use of photocatalysts in the removal of water pollutants is very much considered. Meanwhile, titanium dioxide with unique properties has a special place. The functional drawbacks of photocatalytic nanoparticles have led to the production and application of their various geometric structures. Synthesis of fibers is performed as a single-dimensional structure in a variety of methods. In this study, TiO2 fibers were synthesized using natural silk. Silk fibers, with good surface properties, uniformity of size and easy removal, are the perfect choice for producing nano-fibers. The synthesized structure was evaluated by analyzing XRD, SEM, FTIR, and BET. The results showed that after calcination at 450° C, there are only two anatase and rutile phases in the fibers. In fact, the sample was removed entirely from silk by heating and other analyzes also confirmed this. The photocatalytic performance of the synthesized fiber was analyzed by removing methyl orange. After 210 minutes, 94% of the dye was degraded by TiO2 fibers.

Introduction: Organic antibacterial materials have been used as insecticides and bactericides for many years. Unfortunately, high temperatures in manufacturing process reduce their antibacterial properties. However, inorganic materials of antibacterial agents have excellent bacterial resistance and thermal stability. Over the past few decades, inorganic nanoparticles whose structures exhibit significantly novel and improved physical, chemical and biological properties and functionality due to their nano-scale size have elicited much interest. Methods: The aim of this study was to investigate the antibacterial properties of one kind of nano-specimen (TiO2 nanoparticle) against Escherichia coli and Streptococcus aureus. Our study was research perusal. In the first study, the optical density of E. coli and S. aureus cultures were observed in the presence of 0.01%, 0.75% and 1.5% of TiO2. In the second study, 6.3 log CFU/ml of E. coli and S. areus were separately exposed to 1.5% TiO2 at 37°C in water. In third study, we studied thew growth of E.coli in solid medium with and without nanoparticles. Results: The presence of 0.01% TiO2 nanoparticles didn’t have a statistically significant effect, but in the presence of 0.75% and 1.5% nanoparticles, the bacterial colonies decreased significantly. In the control group, bacterial cells survival was nearly 13 days, while complete cell death of E. coli was seen when 1.5% TiO2 was applied for 24 hours. The same experiment for S. aureu, showed that complete cell death occured when the bacterial culture was exposed to 1.5% TiO2 for 16 hours. It was shown that presence of 1.5% TiO2 in the solid medium suppressed the growth of E. coli 5.6 times more (p < 0.001). Discussion: Our findings showed antibacterial effects of TiO2 nanoparticles against both bacteria, but S. areus bacteria were more sensitive to nanoparticles as compared to E. coli bacteri.

In particular, the inappropriate/inevitably discharge of dye-containing effluents is undesirable because of their color, resistant to the biological treatment systems, toxic, and their carcinogenic or mutagenic nature to life forms. About fifty percent of the washing dye liquor is discharged into the water environment. Fe3O4@SiO2@TiO2 nanoparticles, were prepared, characterized and tested as photocatalyst in the removal of Reactive Black B (RBB) dye by a photocatalytic process. The effect of photocatalyst concentration, pH and temperature in the photo degradation kinetics is discussed in terms of the Langmuir–Hinshelwood (L-H) model. SEM and TEM characterizations confirmed the Fe3O4@SiO2@TiO2 nanoparticel, revealed that the obtained particles a spherical morphology with sizes about 100 nm. The DRS pattern of Fe3O4@SiO2@TiO2 shows the energy band gap value of photocatalyst is 2.75 eV. The presence of Fe3O4, SiO2 and anatase TiO2 in the as-synthesis magnetic nanoparticle were confirmed by FTIR and XRD analysis. The Fe3O4@SiO2@TiO2 photocatalyst in combination with ultraviolet irradiation and under optimal conditions can destroy 100% of RBB after 120 min. Furthermore, the magnetic photocatalyst was efficiently separated from the solution with the help of a magnet and shown the capable of reusability up to 10 times without reducing their efficiency.

In this work, the TiO2 nanoparticle modified carbon ionic liquid electrode (CILE) was employed as a sensitive sensor to investigate the electrochemical behavior of indomethacin (IND). This nanocomposite sensor has been fabricated by incorporation of TiO2 nanoparticles and the ionic liquid 1-hexylpyridinium hexafluorophosphate (HPFP). The surface of the electrode was studied by scanning electron microscopy (SEM). Differential pulse voltammetry (DPV) was used for quantification of sub-micromolar amounts of IND. Electrochemical parameters of the electrode reaction of IND, including the electron transfer coefficient (α ) and the electron-transfer number (n), were calculated by cyclic voltammetry (CV) methods. Under selected conditions, the anodic peak current was linear for the concentration of IND in the broad range of 1. 0 × 10-7-1. 0 × 10-4 M with the detection limit of 2. 1 × 10-8 M. Moreover, the analytical performance of the proposed method for the determination of IND content in plasma samples was evaluated with good sensitivity and acceptable recoveries.