Rutile Phase TiO2 Nanoparticles Research Articles

Comparative Assessment of Crystallographic Phase Stability of Anatase and Rutile TiO2 at Dynamic Shock Wave Loaded Conditions

In the present research article, authors have experimentally evaluated the shock wave resistant properties of technologically potential materials of the anatase and the rutile phase TiO2 nanoparticles at the dynamic shock wave loaded conditions. The shock wave resistant behavior has been quantitatively drawn utilizing the crystallographic phase stability of the test samples for which the required crystallographic information has been extracted from the powder XRD patterns. Based on our observed experimental results as well as the respective interpretations, it is strongly authenticated that Rutile TiO2 NPs are suitable candidates for aerospace and defense industrial applications of materials fabrications because of the outstanding shock resistant properties than that of Anatase TiO2 NPs which undergo the crystallographic phase transition of rutile-TiO2 at shocked conditions.

Investigation of photocatalytic properties of TiO2 nanoparticles belonging to rutile phase

In this article, photochemical dissolution of phenol solution was carried out by ALDKIT001 reactor in the presence of TiO2 nanoparticles possessing rutile phase, the physical and chemical properties of these nanoparticles have been investigated. Photochemical dissociation in the UV field was performed using a Varian device. Photochemical decomposition of phenol was confirmed by gas chromatographic mass spectroscopy.Therefore, we carried out the decomposition of phenol by photochemical reactions using rutile phase TiO2 nanoparticles to purify phenol from wastewater. After photolysis process, 99% phenol decomposition has been occurred.

Tailoring the structural properties and electronic structure of anatase, brookite and rutile phase TiO2 nanoparticles: DFTB calculations

In this study, we perform a theoretical investigation using the density functional tight-binding (DFTB) approach for the structural analysis and electronic structure of anatase, brookite and rutile phase TiO2 nanoparticles (NPs). Our results show that the number of Ti-O bonds is greater than that of O-O, while the number of Ti-Ti bonds is fewer. Thus, large amounts of O atoms prefer to connect to Ti atoms. The increase in the temperature of the NPs contributes to an increase in the interaction of Ti–O bonding, but a decrease in the O-O bonding. The segregation of Ti and O atoms shows that Ti atoms tend to co-locate at the center, while O atoms tend to reside on the surface. Increasing temperature causes a decrease of the bandgap from 3.59 to 2.62 eV for the brookite phase, which is much more energetically favorable compared to the bulk, while it could increase the bandgap from 3.15 to 3.61 eV for anatase phase. For three-phase TiO2 NPs, LUMO and Fermi levels decrease. The HOMO level of anatase phase NP decreases, but it increases for brookite and rutile phase TiO2 nanoparticles. An increase in the temperature contributes to the stabilization of anatase phase TiO2 NP due to a decrease in the HOMO energies.

Interaction of pharmaceutical ionic liquids with TiO2 in anatase and rutile phase

The coating of predominantly anatase and rutile phase TiO2 nanoparticles, with IL-APIs derived from ibuprofenate and containing lidocaine ([LID][IBU]) and bupivacaine ([BUP][IBU]) cations, and with an IL-API derived from docusate and containing the bupivacaine cation ([BUP][DOC]), was evaluated. The DSC, PXRD, DLS, and TEM techniques were used to determine the interactions between TiO2 and the IL-APIs. The antifungal activity and cytotoxicity of the IL-APIs were determined, considering biological and biomedical uses involving coated TiO2 nanoparticles. In accordance with DSC and PXRD, the [BUP][IBU] and anatase TiO2 mixture showed the most significant changes in thermal behavior and diffraction pattern compared to the starting materials. Additionally, [BUP][IBU] formed a thicker layer (coating) around the anatase TiO2. The [BUP][IBU] had an acceptable level of toxicity and better antifungal activity (smallest MIC values) than the two other IL-APIs. The mixture of [BUP][IBU] and anatase TiO2 resulted in the most promising interactions for an application involving TiO2 nanoparticle coating.

Ag deposition effects on the photocatalytic activity of nanoparticulate TiO[formula omitted] — Comparison of gamma irradiation and UV irradiation methods

Rutile phase TiO2 nanoparticles were synthesized first by a modified polyol based sol–gel technique. One important aspect of this work is that the less common rutile phase of TiO2 could be synthesized under mild conditions of temperature and pH. Then these TiO2 nanoparticles were impregnated with Ag using radiation methods i.e. UV-radiation and γ-radiation. This resulted in the formation of Ag–TiO2 nanocomposites. The differences in structure, crystallinity and size of the Ag–TiO2 nanocomposites depends strongly on the reductive power of the reducing species involved as has been ascertained by TEM, XRD and XANES study. The weakly reducing free radicals generated from glycerol via the UV-irradiation method leads to formation of tetrapod precursor like composite nanoparticles of lower crystallinity. On the other hand, the strongly reducing hydrated electron (in the γ-irradiation method) leads to single crystalline, discrete and spherical Ag–TiO2 nanocomposites with traces of Ti2O3. We have been successful in preparing Ti2O3 which is a Magneli phase (MP) Ti sub-oxide, without calcination at very high temperatures. The photocatalytic efficiency of the composites is better than TiO2 itself. The photocatalytic efficiency of the nanocomposites depends on their structure and crystalline nature which can be ultimately correlated to the efficiency of production of active oxygen species like •OH. The presence of the narrow band gap Ti2O3 phase enhances photocatalytic activity of rutile TiO2.

Growth of anatase and rutile phase TiO2 nanoparticles using pulsed laser ablation in liquid: Influence of surfactant addition and ablation time variation

Titanium dioxide (TiO2) nanoparticles were grown using nanosecond pulsed laser ablation of Ti target in DI water and in 0.001M sodium dodecyl sulfate (SDS) surfactant aqueous solution. Growth was carried out with varying ablation times i. e. 30min, 60min and 90min. The objective of our study was to investigate the influence of variations in liquid ambience conditions on the growth of the nanoparticles in a pulsed laser ablation in liquid (PLAL) process. Size, composition and optical properties of the grown TiO2 nanoparticles were investigated using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), optical absorption, photoluminescence (PL) spectroscopy and X-ray diffraction (XRD) studies. The obtained nanoparticles of TiO2 were found almost spherical in shape and polycrystalline in nature in both the liquid mediums i.e. DI water and aqueous solution of surfactant. Nanoparticles number density was also found to increase with increasing ablation time in both the liquid mediums. However crystalline phase of the grown TiO2 nanoparticles differs with the change in liquid ambience conditions. Selected area electron diffraction (SAED), PL and XRD studies suggest that DI water ambience is favorable for the growth of anatase phase TiO2 nanoparticles for all ablation times. While Surfactant added water ambience is favorable for the growth of rutile phase TiO2 nanoparticles but for shorter ablation times of 30min and 60min only, for longer ablation time of 90min anatase phase was also observed along with the rutile phase TiO2 nanoparticles. The formation of anatase phase in DI water and rutile and anatase phase in aqueous solution of surfactant is explained on the basis of varying thermodynamic conditions with the two different liquid ambiences and different ablation times.

Encapsulation of curcumin over carbon dot coated TiO2 nanoparticles for pH sensitive enhancement of anticancer and anti-psoriatic potential

The surface engineering of rutile phase TiO2 nanoparticles was performed by carbogenic carbon dots for biological applications.

The effect of rate of hydrolysis on structural and optical properties of the TiO2 nanoparticles prepared by a sol–gel method

The nanocrystalline TiO2 powders with different crystallinity and phase structures were obtained by controlling hydrolysis rate and annealing temperature. Rutile phase TiO2 nanoparticles with crystallite sizes of about 80nm, were obtained by annealing the TiO2 powders at 700°C. The crystallite sizes of anatase phase TiO2 increases from 8 to 11nm and band gap energy ranges from 2.49 and 3.26eV, calculated using XRD pattern and UV–vis reflectance spectra, respectively. In agreement with change of the TiO2 band gap after different rate of hydrolysis the PL emission peak in the UV region shift slightly from 335 to 339nm, which corresponds to the direct recombination between electrons in the conduction band and holes in the valence band. The defect related emission shifted from 376 to 385nm with the change in the rate of hydrolysis. TiO2 nanoparticles synthesized at slow hydrolysis rate (6ml of H2O) shows the attainment of best luminescence and maximum reflectance in the visible range. Therefore, these TiO2 nanoparticles can also be employed as coating material to develop reflectors with maximum diffuse reflectance.

Novel synthesis of rutile titanium dioxide–polypyrrole nano composites and their application in hydrogen generation

This work presents the first report of rutile titanium dioxide (TiO2)–polypyrrole (PPy) nanocomposites prepared by chemical polymerization of pyrrole in situ in the presence of pure rutile phase TiO2 nanoparticles. The TiO2 rutile nanoparticles were made in water while the composite was made in a biphasic ionic liquid–water system. We attempted for the first time to split water under sunlight with this recoverable photocatalyst.

Using Thin Films of Rutile-Phase TiO2 Nanoparticles as Photoactive Material in Metal-Semiconductor Structures with Low Thermal Processing

Rutile-phase TiO2 nanoparticles are embedded within an organic SiO2 matrix (Spin-On Glass) and the final suspension is deposited by spinning on (a) thin aluminum stripes or (b) in between thin aluminum films and ultra-thin titanium stripes. The maximum processing temperature for both devices is 220 � C. The first device is a “horizontal” TiO2:SiO2/Al/Glass photoactive structure which is then electrically characterized under dark and illuminated conditions (I–V -Light) so that the total resistance of a simple aluminum stripe is measured before/after ultraviolet-visible (UV-Vis) irradiation. Compared to dark conditions, excess carriers are photogenerated within the TiO2 nanoparticles during light exposure and they are transferred to both ends of the aluminum stripe after applying a low potential difference. A large decrease in the resistance of the aluminum stripe (down to 43% of its original value) is obtained when this horizontal structure is irradiated with UV-B light thus acting as a photoresistor. The second device is a “vertical” Ti/TiO2:SiO2/Al/Glass photoactive structure. Here, the path for photogenerated and electrically-driven carriers occurs vertically, or inside a Metal-Insulator-Metal (MIM) capacitor. Because of the ultra-thin titanium layer (100 A in thickness), this gate electrode is highly transparent to most of the UV-Vis irradiation so that when all carriers are being photogenerated, they are almost immediately separated at the top/bottom electrodes by a small applied electric field due to the thin and high-dielectric constant of the photoactive TiO2:SiO2 film. This way, a fast and large increase/decrease in gate current (about 4–7 orders of magnitude) is observed when this device is under illumination/dark conditions. This vertical structure operates as a photocapacitor, where all photogenerated carriers could be efficiently stored within the MIM capacitor itself and thus, enable simultaneous conversion and storage of solar energy in the same device.

Ionothermal synthesis of TiO2 nanoparticles: Photocatalytic hydrogen generation

Rutile phase TiO2 nanoparticles have been successfully prepared at 120°C for one day via the ionothermal method using imidazolium based functionalized ionic liquid. The obtained products have been characterized by various techniques. XRD pattern shows rutile phase with crystallite size ∼15nm. FTIR shows a band at ∼410cm−1 assigned to Ti–O–Ti stretching vibrations and few other bands due to the presence of ionic liquid. UV–vis studies show maximum absorbance at ∼215nm due to the imidazolium moiety and a band at 316nm due to TiO2 nanoparticles. TEM images show that the size of particle is ∼30nm. TG-DTA shows weight loss corresponding to the formation of stable TiO2 nanoparticles. The rutile TiO2 nanoparticle is a promising material for hydrogen generation through photocatalysis.

Surface Texturing of TiO2 Film by Mist Deposition of TiO2 Nanoparticles

Abstract Unique and various microstructures of titanium oxide (TiO2) film including macroporous structure, chromatic veins and rings, have been easily fabricated by mist deposition method on silicon substrate with mild preparation conditions. Rutile phase TiO2 nanoparticles were directly used as starting material to prepare film and led to a simple preparation process. It was found that several different microstructures existed in the sample and changed with the varied positions from the center to the edge of the film when the concentration of the TiO2 suspension is 0.06 mol/l, the deposition time is 30 min, the flow rate is 1 l/min and the temperature is 150°C. The surface texturing shows apparent distinction as the concentration of the TiO2 suspension decreased to 0.03 mol/l and 0.01 mol/l.

Preparation and Photocatalytic Performance of Titania Nanotubes Loaded with Ag Nanoparticles

Titania nanotubes (TNTs) were synthesized by hydrothermal treatment of rutile-phase TiO2 nanoparticles in 10 mol·L-1 NaOH solution at 110 ℃ for 24 h. The Ag loaded titania nanotubes(Ag/TNTs) were obtained by chemical deposition method with the TNTs suspending in the AgNO3 solution (pH=8) at 50 ℃. The characterizations of the as-synthesized samples were performed by TEM, EDS, XRD, XPS, and UV-Vis spectra. The photocatalytic performance of the Ag/TNTs was investigated by UV-light induced photocatalytic decomposition of methyl orange(MO). The results showed that the inner/outer diameters of TNTs were about 6/10 nm and the length was several hundred nanometers. Both the shape and the crystalline of the nanotubes were not changed after the modification. The zero oxidation state Ag quantum dots, about 4 nm in diameter, were well dispersed on the external surface of the nanotubes. Ag/TNTs exhibited enhanced absorption at the visible range in the UV-Vis spectra. The Ag nanoparticles were found to significantly enhance the photocatalytic activity of TiO2 nanotubes, and the catalyst system was demonstrated to be highly efficient for the UV-light induced photocatalytic decomposition of MO compared to both rutile-phase TiO2 nanoparticles and pure TNTs. After irradiation for 60 min, the decomposition rates of MO solution in rutile-phase TiO2 nanoparticles, TNTs, and Ag/TNTs system were 46.8%, 57.2%, and 92.2%, respectively.