The light-induced phase transition of TiO 2 nanoparticles from anatase to rutile structure is reported depending on the surrounding environment, the transition being accomplished under oxygen-poor conditions. The transition mechanism is interpreted in the framework of oxygen adsorption and desorption phenomena with the involvement of surface oxygen …
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The light-induced phase transition of TiO 2 nanoparticles from anatase to rutile structure is reported depending on the surrounding environment, the transition being accomplished under oxygen-poor conditions. The …
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Titanium dioxide (TiO 2) is an excellent photocatalyst and transparent conducting oxide.It has two major crystal structures: rutile and anatase. Anatase TiO 2 is valuable from an industrial point of view because it typically displays better photocatalytic and electronic transport properties than rutile TiO 2.To further extract the functional …
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TiO 2 (B) is a less stable phase of TiO 2 than anatase and rutile . When compared to anatase, rutile, and brookite, TiO 2 (B) is the least dense polymorph of TiO 2 . TiO 2 (B) is suitable for use as a place of Li intercalation because it has a structure that is relatively open, with free space and continuous channels .
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The TiO 2 coating exhibits a rarely-reported microstructure comprising anatase and rutile in a composite with amorphous carbon. Columnar anatase single crystals are segmented into 15–20 nm...
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Anatase and rutile have a tetragonal geometry, differently from brookite, which has an orthorhombic geometry. In rutile, the "TiO 6 " octahedron is slightly distorted, while anatase consists of ...
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Depositing additional TiO 2 films onto TiO 2 substrates could potentially be useful in several applications. Surface defects or rough morphologies of a previously prepared surface could be repaired. Since it is difficult to grow bulk anatase TiO 2 crystals, naturally formed ones that contain impurities are used often in surface science studies, …
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The general perception that anatase has a higher photocatalytic activity compared to rutile TiO 2 is confirmed by our measurements on extended planar …
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We analyzed successfully the refractive index n, extinction coefficient k, and optical band gap E g of the fabricated polycrystalline and epitaxial TiO 2 films of rutile and anatase films by spectroscopic ellipsometry (SE). The provided samples were prepared by rf magnetron sputtering of TiO 2 target with Ar gas plasma under a variety of sputtering …
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Therefore, anatase TiO 2 hollow nanospheres show excellent high-rate performance. Through ex situ field emission scanning electron microscopy, it was revealed that the TiO 2 hollow nanosphere architecture can be maintained for hundreds of cycles, which is the main reason for its superior cyclability.
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TiO 2 has many polymorphs, among which rutile is the most thermodynamically stable. Bulk anatase TiO 2 is usually a metastable phase at room temperature. Hence, phase transformation of bulk rutile TiO 2 to anatase TiO 2 by heat treatment is thermodynamically forbidden. However, the stability of TiO 2 polymorphs is …
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Rutile (R–TiO 2) and anatase (A–TiO 2) are used as supports to vary interfacial structures. RuO 2 shares the same lattice structure with R–TiO 2, which can lead to a high interfacial ...
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The structures of the rutile and anatase are shown in Fig. 1 (a) and (c), respectively, where the typical intrinsic defects, O v and Ti int, are also indicated.Rutile TiO 2 has a six-atom tetragonal unit cell with space group P 42 /mnm and lattice parameters a = b = 4.594 Å and c = 2.959 Å at room temperature [32].Similar to rutile, anatase TiO 2 …
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Rutile and anatase are two widely used phases of TiO 2, anatase being the more photocatalytically efficient for reasons that are not fully understood [14,15]. In addition to the intrinsic natures of the aforementioned phases, energetics, concentration, and location of O-vacancies could be significant factors in their photocatalytic activity.
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Using a simple aqueous precipitation method based on a low-cost titanium oxysulfate precursor, we have prepared three TiO 2 polymorphs: anatase, rutile, and brookite. Although the anatase form can be directly obtained from the thermolysis reaction of an oxysulfate solution, the rutile and the brookite have been prepared by the addition of …
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However, the reasons for the differences in photocatalytic activity between anatase and rutile are still being debated. In this work, the band structure, density of states, and effective mass of photogenerated charge carriers for anatase, rutile and brookite TiO 2 are investigated by the first-principle density functional theory calculation ...
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Results of the performed Raman study indicate that the two TiO 2 polymorphs, rutile and anatase, occur together in samples from WBA. Moreover, as Fig. 7 illustrates, they can be intergrown in ...
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Rutile TiO 2 is also chemically more stable and potentially cheaper to produce than anatase 26. These findings suggest that additional research on rutile TiO 2 from the perspective of solar energy ...
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[ 23] In the present study, we aim to provide a comprehensive understanding of initial crystal structures during the reduction process of TiO 2. For this purpose, two …
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We deposited epitaxial anatase and rutile TiO 2 thin films on LaAlO 3 and γ-sapphire 0.5-mm-thick single-crystal substrates, respectively, using the pulsed layer deposition technique with an ...
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The well-distributed anatase of TiO 2 is shown in Fig. 7(a), while the clusters with higher density of mixed and rutile phases of TiO 2 were observed in Figs. 7(b) and …
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Anatase and rutile TiO 2 of the same particle size (Figure S1, Supporting Information) were prepared from the hydrothermal reactions according to previous literature. [24] TiO 2 nanoparticles underwent Mg reduction process at 450 °C in order to avoid the anatase-to-rutile phase transition.
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A general consensus places the bandgaps of rutile and anatase TiO 2 at 3.03 and 3.20 eV, respectively. In 1996, electrochemical impedance analysis established that the flatband potential of...
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The smaller the size of the TiO 2 nanoparticles, the greater the TiO 2 /C heterointerfaces. And both experimental tests and theoretical calculations implied that, compared with rutile TiO 2, the TiO 2 /C heterointerfaces constructed by anatase TiO 2 demonstrated a higher catalytic efficiency due to the stronger absorbability toward LiPSs and ...
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Anatase/Rutile Phases Regulating TiO/C Heterointerfaces for Enhanced Polysulfide Conversion in Sulfur Cathodes,,,,,,,, Jian-Wen Shi, Jiujun Zhang*, and Xifei Li* Cite …
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Figure 1 illustrates the most important experimental results concerning the first nanomaterial system—undoped n-type TiO 2.XRD (Fig. 1a) for as-prepared TiO 2 nanopowder indicates the predominance of anatase polymorphic form. The content of rutile is low as determined from the analysis of this XRD pattern and amounts to f R = 0.07. As …
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Electrochemical impedance spectroscopy, photoelectron spectroscopy, and Kelvin probe measurements on various TiO 2 single-crystal surfaces show that the position of the Fermi level and the conduction band minimum depend significantly on the sample environment (vacuum, air, water vapor, and aqueous or aprotic electrolyte solutions). In …
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Titanium dioxide (TiO 2) is one of the most popular photocatalysts.In fact, based on an analysis with SciFinder of the American Chemical Society, 45% of documents concerning photocatalysis in the last two years deal with TiO 2.There are two major polymorphs for TiO 2: anatase and rutile with the band gap energy of 3.2 and 3.0 eV, …
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CO 2 photoreduction with water vapor has been studied on three TiO 2 nanocrystal polymorphs (anatase, rutile, and brookite) that were engineered with defect-free and oxygen-deficient surfaces, respectively. It was demonstrated that helium pretreatment of the as-prepared TiO 2 at a moderate temperature resulted in the creation …
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In this research, the anatase phase TiO 2 kept its sheet-like structure after one hour annealing at 1000 °C, and rutile phase TiO 2 was not found by GIXRD and Raman measurement. Therefore, we can conclude that the anatase phase TiO 2 films synthesized in this research showed high thermal stability up to 1000 °C.
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Experimental studies of the surface reactions of photocatalyzed or photoelectrocatalyzed water oxidation on rutile, anatase, and brookite TiO2 show significant differences between the three polymorphs. Yet a fundamental understanding of the differences is still lacking. In this work, we carried out a systematic comparative density …
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One oxide surface of major fundamental and practical interest is rutile TiO 2 (110) (R-110 in the following), that is widely considered the prototypical metal oxide surface (3–9).Extensive investigations of gas-phase water adsorption on R-110 have established that oxygen vacancies—the most common defects on this surface—dissociate water and become …
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In TiO 2, both the anatase and rutile polymorphs are also built on a network of coordinated TiO 6 octahedra, but they significantly differ in their structural properties.
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The physicochemical properties of titanium dioxide (TiO 2) depend strongly on the crystal structurepared to anatase, rutile TiO 2 has a smaller bandgap, a higher dielectric constant, and a higher refractive index, which are desired properties for TiO 2 thin films in many photonic applications. Unfortunately, the fabrication of rutile thin films …
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TiO 2 exists naturally in three crystalline forms: Anatase, rutile, brookite, and TiO 2 (B). These polymorphs exhibit different properties and consequently different photocatalytic performances. This paper aims to …
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The more favorable ground state HOMO level alignment for A-TiO 2 (101) may explain why the anatase polymorph shows higher photocatalytic activities than the rutile polymorph. Our results indicate that (1) hole trapping is more favored on A-TiO 2 (101) than R-TiO 2 (110) and (2) HO@Ti cus is more photocatalytically active than intact H 2 O@Ti cus.
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Density functional theory calculations were used to investigate the phase transformations of Li x TiO 2 (at 0 ≤ x ≤ 1), solid-state Li + diffusion, and interfacial charge-transfer reactions in both crystalline and amorphous forms of TiO 2.It is shown that in contrast to crystalline TiO 2 polymorphs, the energy barrier to Li + diffusion in amorphous …
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1 Introduction Since the discovery by Fujishima and Honda 1 of the photocatalytic ability of titanium dioxide, TiO 2, this system has been extensively studied for hydrogen fuel production through water splitting. 2 Although the anatase TiO 2 was found to be the polymorph with the most photocatalytic efficiency, the (110)-rutile surface has become …
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The bandgap of rutile and anatase TiO 2 is of 3.0 and 3.2 eV respectively. Counting of all the possible alignments of their relative position of the conduction band (CB) ...
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blue.18 TiO 2 heterophase interfaces have been proved to have more superior photocatalytic activity than pure anatase or rutile phase TiO 2 by many researchers. Lyu et al.19 fabricated a TiO 2 hollow heterophase junction by coating anatase TiO 2 hollow spheres with porous amorphous TiO 2, and the obtained TiO 2
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