Properties Of Titanium Research Articles

Rationalizing Fe-Modified TiO2 through doping, composite formation, and single-phase structuring for enhanced photocatalysis via inter- and intra-charge transfers

This study sheds light on how the properties of titanium dioxide (TiO2) are influenced when it is modified with iron (Fe), leading to the formation of Fe-doped-TiO2, Fe2O3-TiO2 composite, and single-phase FeTiO3 systems. The structural formation of the materials, oxidation state, and chemical environments of the elements are analyzed using XRD and XPS techniques. Band structures with UV–visible light driven properties and suitable redox potentials with improved recombination resistance along with an active inter- and intra-charge transfers were observed for Fe2O3-TiO2 and FeTiO3 systems. The photocatalytic efficiency was found to be superior for FeTiO3 system, degrading ∼97 and 100 % of phenol, malachite green and rhodamine B dyes in 150 min, respectively along with enhanced recyclability. Interestingly, a competitive S- and Z-scheme was predicted for Fe2O3-TiO2 composite, explaining its photocatalytic mechanism. The scavenger and total organic carbon analyses revealed the radicals driving the photocatalytic reactions and the nature of degradation products, respectively.

Wettability of anatase TiO2 surface: Effect of niobium doping

The effect of niobium doping on the hydrophilic behavior of anatase TiO2 surface was demonstrated on a series of x-Nb-TiO2 nanocoatings with dopant concentrations in the range of 0.0 - 1.0 at.% Nb. Thin films prepared on glass substrates from sols by dip-coating were characterized by tensiometric, work function and isoelectric point measurements along with FT-IR spectroscopy in situ method. Using macroscopic and microscopic techniques, it was found that, at low doping level, it is the functionalization of the anatase surface with niobium ions that leads to a drastic change in its surface acid-base as well as electronic properties and, as a consequence, to a sharp increase in the initial surface hydrophilicity. The rearrangement in the hydroxyl‑hydrated layer with the formation of additional hydroxyl groups as a result of surface functionalization has an increased effect on wettability only at low levels of niobium inclusion, whereas with increasing dopant content the electronic factor plays a significant role on the properties of titanium dioxide, including its wettability. The kinetic dependencies of the photoinduced superhydrophilic conversion for all Nb-doped titanium dioxide surfaces were obtained and discussed in terms of proposed mechanism. Both the initial hydrophilic state and the initial rate of photoinduced hydrophilic conversion depend on the Nb concentration in titanium dioxide, while the final UV-induced superhydrophilic state is achieved for all Nb-doped TiO2 regardless of the dopant content.

Se (IV)-Doped Monodisperse Spherical TiO <sub>2</sub> Nanoparticles for Adhesively Bonded Joint Reinforcing: Synthesis and Characterization

<div>This study focused on the synthesis and characterization of monodisperse spherical TiO<sub>2</sub> nanoparticles doped on the surface with Se (IV) in order to increase the mechanical properties of the bonded joint reinforcing. Work will begin with the synthesis of monodisperse quasi-spherical TiO<sub>2</sub> nanoparticles with a modal diameter of less than 20 nm, using the sol-gel technique. Se (IV) selenium surface doping changed the specimen’s chemistry and physics. Different initial concentrations of the doping element will be tested. Next, a physicochemical characterization of the different solid systems will be carried out in order to determine the effect of the doping element on the properties of titanium dioxide. Their morphology and size will be studied through transmission electron microscope observations; volume chemical composition by X-ray diffraction analysis, EDX (energy-dispersive X-ray), and XRF (X-ray fluorescence). The careful selection of 4% and 6% concentrations produced the optimum nanoparticle increase and cohesive structure preservation. These findings demonstrate that Se (IV)-doped monodisperse spherical TiO<sub>2</sub> nanoparticles may improve adhesive junction mechanical properties, enabling the development of better adhesive formulations.</div>

MODIFICATION METHODS TO ENHANCE THE PERFORMANCE OF TiO2 IN PHOTOCATALYSIS

With industrial development and changes in human lifestyle, organic pollution has become an increasingly serious problem, posing a serious threat to the ecological environment and human health. As an emerging advanced oxidation process, titanium dioxide–based photocatalysis has shown unparalleled potential in solving environmental pollution problems due to its stable catalyst properties, mild reaction conditions, environmental friendliness and low cost. However, titanium dioxide is limited in its photocatalytic efficiency by the fact that it can only be excited by ultraviolet light, its carriers are easily compounded and its adsorption capacity is weak. In order to improve the photocatalytic degradation efficiency of organic pollutants, the properties of titanium dioxide can be enhanced by means of modification. This article mainly reviews several major modification methods and research progresses of semiconductor titanium dioxide materials for the degradation performance of organic pollutants in the environment, and focuses on the advantages of the new Metal Organic Frameworks/ titanium dioxide composite system in enhancing the degradation performance of organic pollutants. Finally, the application prospects and key issues of Metal Organic Frameworks/ titanium dioxide materials in photocatalytic treatment of organic pollution problems are presented.

Apatite-coated Ag/AgBr/TiO2 nanocomposites: Insights into the antimicrobial mechanism in the dark and under visible-light irradiation

For the first time, titania-based photocatalysts with different crystalline compositions (anatase/rutile) and morphology (irregular and faceted nanoparticles) were modified with Ag/AgBr and apatite (HA). The antimicrobial activity was tested for Escherichia coli (E. coli) bacteria and Candida albicans (C. albicans) fungi under visible-light illumination and in the dark for HA-covered and uncovered nanocomposites. It has been found that antimicrobial inactivation mechanism follows two different pathways, depending on the conditions (dark vs. irradiation), i.e., HA loading on the photocatalyst surface affects only the microorganism nourishment from the surrounding media (growth inhibition) in the dark, but significantly induces outer cell wall destruction (leading even to the mineralization) in the presence of light. Furthermore, 2-propanol oxidative decomposition was also investigated. The obtained results suggest that the improved photocatalytic activity of HA-covered samples originates from phosphate anions in HA, hindering the charge carriers’ recombination. In bacteria case, titania's properties are key factor for high bactericidal effects, such as anatase form (electrostatic attraction between microorganisms and photocatalyst surface) and fine crystallites, as opposed to yeast inactivation resembling 2-propanol oxidation, i.e., photocatalytic mechanism, based on reactive oxygen species. Concluding, HA/Ag/AgBr/TiO2 samples are promising “green” materials for decomposition of both microbiological and chemical pollutants.

Effects of particle collection in a premixed stagnation flame synthesis of sub-stoichiometric [formula omitted] nanoparticles

Flame synthesis is a simple method to prepare sub-stoichiometric titanium dioxide (TiO2-x) nanoparticles. A rotating stagnation plate is often used as a substrate and to provide a cooling mechanism. The collection of particles from the rotating plate could be done in two ways: the conventional interval particle collection (IPC) method and a continuous particle collection (CPC). The effects of the deposition time and the rotation speed on the properties of titanium dioxide (TiO2) particles are investigated experimentally. For IPC, it was found that the properties of the collected samples are dependent on the deposition time. This creates an undesirable correlation between properties and synthesis yield. On the other hand, CPC approach allows for a continuous synthesis in which the particle properties are invariant with respect to the synthesis yield. The tunability of the particle properties is still achievable by controlling the rotation speed in the CPC.

Comparative study of the effect of Mg, Zn and Ag dopants on properties of titanium dioxide as mesoporous ETL for photovoltaic application

As the electron transport layer (ETL) has a pivotal role in extracting and transporting the photogenerated electrons leading to lesser recombination of charge carriers in perovskite solar cells (PSCs), we reported on the modification of structural, optoelectronic and optical characteristics of ETL of PSCs. ETL (titanium dioxide, (TiO2)) modified by incorporation of metal ion dopants magnesium, zinc, and silver named Mg–TiO2, Zn–TiO2, Ag–TiO2 respectively revealed fascinating characteristics in terms of electron injection, porosity, diffusion length, and nonlinear optical properties. The decrease in bandgap Ag–TiO2 < Zn–TiO2 < Mg–TiO2 < TiO2 aligned the TiO2 conduction and valence band which makes the injection of electrons from perovskite active layer conduction band to ETL conduction band easier. This helped to get reduced recombination and enhanced electron transport. Surface morphology revealed the increase in porosity as Ag–TiO2 > Zn–TiO2 > Mg–TiO2 > TiO2 which suggested the easy infiltration of the perovskite active layer into ETL and lead to enhanced absorption of the incident light. Optoelectronic characterization by steady-state photocarrier grating technique gave an increase in minority charge carriers diffusion length Ag–TiO2 (99 nm) > Zn–TiO2 (70 nm) > Mg–TiO2 (67 nm) > TiO2 (61 nm). Nonlinear susceptibility of third-order (χ (3)) obtained by the z-scan technique is of the same order for TiO2, Mg–TiO2, Zn–TiO2 whereas it decreases for Ag–TiO2. With the help of obtained experimental results, the authors concluded that Ag–TiO2 is the promising ETL among the introduced materials followed by Zn–TiO2, Mg–TiO2, and TiO2.

Study of humidity sensing properties and ion beam induced modifications in SnO2-TiO2 nanocomposite thin films

Swift heavy ion beam induced dense electronic excitation in the nanocomposite thin film is a unique way to introduce various modifications such as track formation, atomic transport and phase transformation. Therefore, this work based on the modification in the properties of Titanium dioxide and Tin oxide nanocomposite thin films prepared by RF sputtering deposition technique in the mol% 50:50 on ITO coated glass and silicon substrates. The prepared nanocomposite thin films annealed at 500 °C and irradiated with SHI of 150 MeV Fe11+ ion beam with varied ion fluences ranging from 5 × 1012to 5 × 1013 ions.cm−2. The SRIM simulation was confirmed the electronic energy loss (Se) as 1.038 × 102 eV/nm, nuclear energy loss (Sn) as 1.33 × 10−1 eV/nm and the projectile depth of the iron ion inside the thin films was founded to be 17.18 um. Structural analyses of pristine and irradiated thin films were analyzed by X-ray diffraction technique. Changes observed in the peak intensity were confirmed by the significant variations in crystallite size, which was calculated by the Debye Scherrer equation. The crystallite size of all samples was found to be improved from 59 nm to 141 nm. The influence of ion irradiation on surface topography of nanocomposite thin films was analyzed by Atomic Force Microscopy (AFM). The sectional analysis of AFM images reveals that the grain size depends on the ion irradiation fluences. The grain size was increased from 52 nm to 129 nm. The optical properties were studied using UV–Visible spectroscopy and Photoluminescence (PL) spectroscopy. Tauc's method was used to calculate the optical energy band gap of the samples. The direct band gap was decreased as ion fluence increases may be due to creation of metastable energy states in between the valance and conduction band. The recombination and separation of photo generated charge carriers were studied by the photoluminescence spectroscopy. Rutherford Backscattering Spectrometry (RBS) was performed on all samples to ensure depth profiling, elemental composition and absence of impurities in titanium dioxide and tin oxide nanocomposite thin films. The response time, recovery time, repeatability and ageing effect after (one, two and three) weeks of nanocomposite thin films were obtained during humidity sensing measurements.

CHARACTERISTICS AND OPTICAL PROPERTIES OF NITROGEN IONS IMPLANTED TiO2 THIN FILM PREPARED BY REACTIVE DC SPUTTERING TECHNIQUE

This study reports on the properties of Titanium Dioxide (TiO2) thin films fabricated by Reactive DC sputtering technique on glass substrate. TiO2 thin films were implanted with several doses of N+ ions namely; (2×1015, 1×1016 and 1×1017 ions/cm2 ) using homemade implantation equipment. The optical properties of N+ ions implanted TiO2 thin films examined by UV-Vis spectrophotometry. The transparency of the N+ ion implanted TiO2 decreased with increasing of N+ ion dosage while the absorption spectrum was shifted toward visible region. The band-gap energy of N+ ion implanted TiO2 exhibited a decrease with various doses from 3.15 eV to 2.52 eV. The intensity of diffraction peak A(101) and R(110) decreased specially at the dose (1×1017 ions/cm2 ). XRD and SEM analyses indicated a degeneration of the crystal quality.

Optical Properties of Composite Materials Based on Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-Phenylenevinylene] and Titanium Dioxide in the Mid-IR Spectral Range

Composite materials based on poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] and titanium dioxide are used in the optoelectronic and chemical industries. A study of the behavior of chemical bonds in the composite and of the influence exerted by an inorganic additive on its properties is topical. The physical properties of the composites are analyzed by IR (infrared) spectroscopy. All the experiments are performed in an oxygen atmosphere at room temperature. The spectral characteristics of the composite in the mid-IR spectral range are examined and the spectral absorption lines are identified. It is shown that the introduction of titanium dioxide into the polymer matrix does not cause intense oxidation processes within the composite. It is found that the main absorption lines characterizing the vibronic properties of titanium dioxide are not subject to spectral shifts within the polymer matrix.

Properties of TiO2/TiOx Active Layers and Fabrication Resistive Switching Device

The electrical and structural properties of titanium oxides TiO2/TiOx fabricated by reactive magnetron sputtering were studied and used in a memristor. X-ray diffraction and [Formula: see text]–[Formula: see text] measurements were performed in order to characterize the fabricated structures.

On the Impact Caused by Titanium Dioxide of Different Trademarks on the Properties of Intumescent Fire-Protective Coatings

The paper overviews the process of thermolysis of fire-retardants based on melamine, ammonium polyphosphate and pentaerythtritol and containing titanium dioxide of different trademarks. The role of titanium dioxide as a component of fire-retardants is revised. Titanium dioxide was perceived only as white pigment, but this paper states that the properties of a charred layer forming from an intumescent coating depend on the properties of titanium dioxide's species, such as surface treatment and crystalline structure. This statement is proven by using thermal analysis of intumescents with different titanium dioxide's trademarks; it shows that rutile titanium dioxide helps forming a charred layer with the highest thermal stability thus fire retardant efficiency grows up. It means that the knowledge of processes which occur in intumescents based on primary products with different qualities helps to create fire-protective compositions which will perform more reliable in case of fire.

Synthesis and Characterization of Titanium (iv) Oxide Loaded with Silver Nano Particles Thin Films

This research investigates effect of annealing temperature on the optical properties of titanium dioxide loaded with silver nanoparticles (TiO2: AgNPs) thin films deposited on glass substrate by spin–coating technique. Silver nanoparticles was prepared using laguminosae-paplionodeae extracts as a reducing agent for silver nitrate and commercially available titanium (iv) oxide was used. Deposition of TiO2:AgNPs blend solution was done in different volume ratio. The blend solution volume ratio of (1:0.2) was deposited at 7 different thicknesses with different speed of revolution per minutes (rpm) for 30 seconds. Annealing of 16 samples deposited at 1000 rpm on the glass substrate was carried out at temperature range of 50°C to 425°C with 10°C interval in a tubular furnance. It is observed from the results that the peak absorption of photon energy occurred at 375°C in the visible range of the wavelength spectrum. Optimal thickness for peak absorbance of the TiO2:AgNPs blend layer occurred at 115 nm in the visible spectrum and at the corresponding spin speed of 1000 rpm. Optimized fabrication process with blend layer thickness of 115 nm yielded the best absorbance at annealed temperature of 375°C in the visible spectrum. The volume ratio of (1:0.2) gave the peak absorption at 0.75 a u. The band gap energy of the blend thin film is 3.58 eV at 375°C in the visible range of wavelength spectrum. It is revealed from the result that the light absorption, broadened absorption spectral range and thermal stability of titanium (iv) oxide film could be enhanced using silver nanoparticles. The results can be therefore used as a guideline for improving the design and fabrication of organic solar cells.

Photothermal Enhanced Photocatalytic Properties of Titanium Dioxide (B)/Glass Fiber Cloth

Photothermal Enhanced Photocatalytic Properties of Titanium Dioxide (B)/Glass Fiber Cloth

Electrochemical Study of Photocatalytic Activity Enhanced By Plasmon Resonance

Titanium oxide has been proven the most promising material for water treatment via Advance oxidation process (AOP) due to its low recombination rate and high capacity to generate hydroxyl radicals, its most important downside is restricted photocatalytic activity to the UV range. Enhancing photocatalytic activity under visible light has been the objective of a lot of researchers around the world. Plasmon resonance in conjunction with traditional semiconductor photocatalyst provides an opportunity to understand and improve on the already useful properties of titanium oxide. The present study is focused on the interaction of an anodized titanium surface (ATS) and silver nanoparticles (Ag-NP) deposited on the ATS by photo electrochemical electroless reduction. Photocatalytic activity enhanced by plasmon resonance is expected to improve the material activity in two fronts, via the metal semiconductor junction where the electron hole (e/h) separation and fast lane charge transfer are induced, and a second front where localized surface plasmon resonance (LSPR) benefit photocatalysis by enabling visible light response, enhancing Visible/UV absorption, local electric fields reducing (e/h) diffusion length, generation of LSPR powered (e/h), local heating effects, lastly molecule polarization. ATS was form by anodic oxidation of a titanium sheet at 30 V for 120 minutes in an organic electrolyte compose of ethylenglicol, NH4F and water at 5%. Subsequently Ag-NP were deposited by photoreduction of 0.1 M AgNO3, The material was characterized by cyclic voltammetry and scanning electron microscopy. The photo response to visible and UV light was evaluated by zero-current chronopotenciometry. The ATS/ Ag-NP system was successfully fabricated showing a porous titanium oxide surface, decorated by Ag-NP with a uniform size of around 60 nm. Results shows an increase in the visible light response provoked by the silver deposit, the way the photocatalytc response is affected appears to be dependent on the amount of silver deposited, and the size of the particles. Further studies on the effect of the nanostructures over the photocatalytic activity are being conducted. Figure 1

Photoelectrochemical Properties of Oxide Systems Formed by Plasma Electrolytic Oxidation

This paper describes the photoelectrochemical properties of titanium oxide formed by plasma electrolytic oxidation. The possibility of correlation between the photoactivity of the formed systems and their impedance characteristics was investigated. Equivalent circuitries which allow explanation of the character of the impedance spectra were constructed and interpreted. The role of heat treatment and surface modification with platinum on the photoelectrochemical and electrochemical characteristics of the formed systems was demonstrated.

Recent advances in titanium dioxide/graphene photocatalyst materials as potentials of energy generation

The properties of titanium dioxide (\(\hbox {TiO}_{2})\)/graphene/graphene oxides (GO) are examined in this study. These views summarize the recent theoretical and experimental novel approaches in the catalytic activity of \(\hbox {TiO}_{2}\)/graphene interface. Imperative results at a level of detail, suitable for upcoming experimental and theoretical researchers involved an overview of the enthralling characteristics of \(\hbox {TiO}_{2}\) and graphene composites were presented. Aspects like crystal lattice, electronic band structure and phonon dispersion, among others that were used to describe the properties of a \(\hbox {TiO}_{2}\) interface with pristine graphene and graphene dioxide among other composites are discussed. In particular, this review covers reactivity, binding energies, geometric structures as well as the photocatalytic activity of anatase \(\hbox {TiO}_{2}\) surfaces with graphene and graphene oxide with hybrid nanocomposites. These views also explore the understanding of the \(\hbox {TiO}_{2}\) interactions with graphene and possible applications. Finally, highlights on the challenges and proposed strategies in developing advanced photocatalytic semiconductor-based composites for water-splitting applications are provided.

Surface Physicochemical and Structural Analysis of Functionalized Titanium Dioxide Films

Titanium and its alloys are recognized as acceptable materials for many applications. The properties of titanium dioxide (TiO2) thin films are directly related to the structural characteristics of the material, which can be modified with tailor-made functional groups. Reactive bifunctional groups can be bound with hydroxyl-terminated TiO2, leading to the formation of self-assembled monolayers or multilayer films. The understanding of such interactions is necessary to design functional oxide coatings for a large variety of applications. In this study, nanosized TiO2 films were synthesized by the sol-gel method and deposited by spin coating technique upon titanium substrate. Subsequently, TiO2 thin films were functionalized with (3-aminopropyl)trimethoxysilane (APTMS), 3-(4-aminophenyl)propionic acid (APPA), 3-mercaptopropionic acid (MPA) or polyethylene glycol (PEG). Surface characterization by XPS, surface roughness, and contact angle indicated successful functionalization and allowed for identification of the preferential conformation of each molecule. APPA and APTMS presented free amine groups indicating the attachment to the surface by carboxyl and silane groups, respectively. Mercapto coupling from MPA showed the formation of S-Ti bonds. PEG-coated surface revealed polymerization of several hydroxyl groups that crosslinked with each other. Analyzing the mode of attachment at the interface of the metal oxide and functional group may help in the development of improved functional materials.

The effect of ionic and electronic properties of titanium oxide on the electrochemical growth and redox behavior of polyaniline on titanium surfaces

Polyaniline (PANI) was electrodeposited directly from aniline (ANI)-containing sulfuric acid media on Ti|TiO2 electrodes, which were prepared in ANI-free 0.5 M H2SO4 solution by applying suitable anodization conditions in order to control the donor density (N D) in the oxide layer of a fixed thickness. By using the suggested procedure, reproducible conditions for the cyclic voltammetric growth of PANI on Ti can be achieved, and most importantly, the properties of Ti|TiO2|PANI electrodes can be modulated to meet the requirements for specific applications. The polymerization rate and the deposited amount of PANI were found to depend strongly on the N D estimated by Mott-Schottky analysis. The redox behavior of the resulted Ti|TiO2|PANI electrodes indicated differences in acid solutions as compared with the corresponding behavior of other PANI-modified metal surfaces. Analysis of the anodic and cathodic electrochemical response of the prepared Ti|TiO2|PANI electrodes discloses the significant role of ionic and electronic properties of the intervening oxide between the metal support and PANI.

Anatase TiO2 (101) and wurtzite ZnO (001) modified polymer for visible light-photocatalytic efficiency enhancement

ABSTRACTPhotocatalytic property of titanium dioxide and zinc oxide was used in several of application in the environmental field due to their high oxidation power and a self-sensitized degradation in a wide range of organic compound. Unfortunately, the large band gap of these metal oxides absorbs only UV radiation and limits the photocatalytic efficiency results in high cost of photocatalytic degradation of environmental pollutant. To be used under visible light irradiation, time-dependent density functional theory was applied to study anatase titanium dioxide (101) and wurtzite zinc oxide (001) with modified organic materials. Four modified structures, including polyisoprene ring, polyisoprene chain, polyacethylene, and polyphenylenevinylene, were investigated. The electronic structure and simulated UV-Vis spectra were analyzed.