Ag-Doped TiO2: Synthesis, Characterization and Photodegradation of 4BS Dye

Ag doped TiO2 nanoparticles with different metallic content (0.0, 0.1, 0.15 and 0.2 wt.%) were prepared by using EDTA-Glycol method. For the sake of comparison blank TiO2 sample is also prepared using same method. All the samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). X-ray diffraction technique revealed that Ag-doped TiO2 has anatase structure and as the concentration of Ag increases the particle size will get decreases. The morphologies of TiO2 samples are influenced by doping Ag as shown by SEM images. The present work is mainly focused on the enhancement of photocatalytic reactivity of as synthesized samples by the photodegradation of 4BS under visible light irradiation using a LED lamp of (15 W) as a light source. A 96.3% of photodegradation of 4BS dye was achieved by utilizing 1 g/L of Ag-doped TiO2 at pH 6 for 100 min.

Photocatalytic degradation of Congo red dye using Fe-doped TiO2 nanocatalysts

Fe-doped TiO2 (2, 5, 10, 15 and 20% wt. of Fe) photocatalysts have been synthesized by sol-gel method using titanium aquacomplex precursor. The structure and morphology have been characterized by XRD, BET, SEM, and EDS analyses, Mossbauer and IR spectroscopies. XRD analysis confirmed the anatase structure. The introduction of ferric ions into the titania structure causes its amorphization. The crystallite sizes of obtained samples are around 3 nm. Fe-doped TiO2 samples possess mesoporous structure and high specific surface area (from 274 m2g-1 for 5Fe-TiO2 to 416.4 m2g-1 for 20Fe-TiO2). Mossbauer spectroscopy data confirms the incorporation of Fe3+ ions in the anatase structure. Photocatalytic degradation of Congo red dye using Fe-doped TiO2 photocatalysts was studied under the UV-A light. Optimized conditions for photocatalytic degradation of CR in the presence of hydrogen peroxide are obtained. It was found that the 2Fe-TiO2 sample in the presence of 20 mM H2O2 solution showed highest efficiency in dye photodegradation (99.4%) under UV-A light. The photodegradation kinetics was analyzed using a smartphone and fits well with first-order kinetics model.

STRUCTURAL, SURFACE AND ELECTROCHEMICAL CHARACTERISTICS OF TiO2 FOR LITHIUM-ION BATTERIES

The paper presents structural, surface, thermodynamic and kinetic characteristics of titanium dioxide samples obtained by means of alkaline hydrolysis of TiCl4 by LiOH solutions and further heat treatment. TiO2 samples have the anatase structure with crystallite size of 7–10 nm. An increase in the heat treatment temperature from 150 °C to 470 °C leads to a decrease in the specific surface area from 404 to 80 m2/g and the total pore volume from 0.340 to 0.152 cm3/g. The influence of electrolyte composition and surface properties of TiO2 on its behavior in cells with lithium anode investigated by means of galvanostatic cycling and impedance spectroscopy is discussed.

The Effect of Acidity and Rotation Speed in Titanium Dioxide Synthesize Process

The aims of this study are to analyze the effect of acidity and rotational speed in the synthesis of TiO2 using the sol-gel method and to analyze the morphology of synthesized TiO2 nanoparticles and commercial TiO2 using XRD to produce semiconductors for Dye-Sensitized Solar Cell (DSSC) applications. The sol-gel method was used to synthesize TiO2 Nanoparticles. Titanium tetra-isopropoxide (TTIP) was used as a precursor with the variable of the magnetic stirrer rotation speed of 500, 1000 and 1500 rpm. Acidification was achieved by adding acetic acid to Sol-gel solution to produce a pH number of 1, 2, and 3. Nanomaterial was observed with an optical microscope and X-ray Powder Diffraction (X-RD) to determine the morphology and phase of TiO2 crystalline. The results showed that the rotational speed and acidity level of the Sol-gel solution ware played an important role to get the best form of a nanoparticle. At a rotation speed of 1500 rpm with pH 3 and 1000 rpm with pH 2 ware shown characteristics similar to commercial TiO2. In addition to that, the results of XRD characterization of synthesized TiO2 was shown a crystal phase of anatase structure with 18,046 nm crystal size compared to commercial TiO2 with anatase structure and crystal size of 15,554 nm.

Revisiting the Sodiation Mechanism of TiO2 via Operando X-ray Absorption Spectroscopy

The sodiation mechanism of TiO2 anatase was thoroughly investigated via X-ray absorption spectroscopy under operando conditions. The data set was analysed via an innovative and smart approach based on chemometric tools that allows the unbiased and reliable extraction of the maximum amount of meaningful information. The resulting data analysis reveals that the electrochemical sodiation mechanism is mainly based on the reduction of Ti4+ to Ti3+, going along with the irreversible amorphisation of the pristine anatase structure. At least one semi-amorphous intermediate is formed during the first discharge, whose local structure resembles those obtained at the end of the charge.

Impact of medical titanium implant surface on the efficiency of fibrointegration

The aim of this study was to study the effect of surface branching of titanium endoprostheses on the efficiency of fibrointegration. The object of the study was samples of titanium alloy Ti6Al4V in the form of disks with a diameter of 5 mm and a thickness of 1 mm with various surface treatments: 1) samples with a rough surface after sandblasting; 2) samples with a rough surface after sandblasting with a bioactive coating of titanium dioxide TiO2 with anatase structure. The study of surface roughness was carried out by profilometry. Evaluation of the spreading and proliferation of cells on the surface of test samples, as well as evaluation of the effectiveness of fibrointegration was carried out according to standard methods using scanning electron microscopy. During the experiments, mesinchymal stem cells were sown on test samples and the test samples were introduced into the soft tissues of experimental animals. Based on the results obtained, it was concluded that the technology of forming rough surfaces by sandblasting does not provide high uniformity and reproducibility in the nanometer range and, apparently, another method for obtaining a rough surface should be chosen. The application of a bioactive coating of titanium dioxide TiO2 with the anatase structure to the surface of titanium endoprostheses increases the efficiency of fibrointegration, however, primarily the fibrointegration of titanium endoprostheses depends on their surface roughness, which determines the concentration of cell structures, the intensity of their adhesion and the ability to fibrointegrative process.

Preparation of TiO2 Thin Films by Sol-Gel Method and Analysis of its Transmittance Based on Computer Image Processing

TiO2 films were prepared by sol-gel method with butyl titanate, anhydrous ethanol, acetyl acetone and hydrochloric acid as raw materials, which were sintered at 380 °C and 530 °C respectively to obtain TiO2 films. XRD was used for analyzing the crystal structure of TiO2 film, and ImageJ software was used to detect the light transmittance of TiO2 film samples. The results show that the film sintered at 530 °C is brookite structure and the film sintered at 380 °C is anatase structure. The increase of sintering temperature is not conducive to the growth of TiO2 film grains. TiO2 films sintered at 380 °C have good light transmittance.