Titanium Oxide Materials Research Articles

Template-Free Synthesis of Phosphorus/Nitrogen-Doped Mesoporous Titania Materials with Excellent Adsorption for Lysozymes.

Element-doped mesoporous titanium oxide has significant advantages in substance separation and adsorption due to its larger specific surface area and stronger hydrophobicity. However, its current synthesis methods have limitations such as complicated preparation process, high production cost, or not being environmentally friendly, and the synthesis of elementally doped titanium oxide materials by simple, low-cost, and green means is the research goal of this study. In this study, phosphorus-doped mesoporous titanium oxides (TiP) materials have been synthesized through a facile template-free method in an ethanol system, which were further modified by nitrogen doping with the use of urea as the nitrogen source. Both the synthesized TiP and P-N codoped sample (N-TiP) are amorphous with mesopores. It was revealed by FTIR and XPS spectra that the formation of Ti-O-P and -O-Ti-N bonds in the synthesized samples was due to the partial substitution of phosphorus for titanium in Ti-O-Ti bonds in mesoporous titanium oxide, while nitrogen replaced some oxygen in the -O-Ti-O bonds in the form of anions. The TiP sample was estimated by the BET method to have a relatively large surface area, up to 317 m2/g. The adsorption of TiP and N-TiP materials to lysozyme protein in a buffer solution at different pH values showed that the adsorption of TiP to lysozyme protein was larger, which was 32.68 μmol/g. It shows that TiP has potential as a multifunctional adsorbent.

A quantitative and qualitative study of gas generation observed in LiFePO4–TiNb2O7 cells

Since 20 years, titanium oxide materials and in particular, lithium titanate spinel Li4Ti5O12 (LTO) were considered as promising negative electrode materials for lithium-ion cells. In the case of the TiNb2O7 compound (TNO), which has a larger theoretical lithiation capacity of 388 mAh g−1, few studies have focused on the outgassing of the material. In this work, we quantified the volume produced as a function of different cycling parameters and then characterized the produced species and show a prevalence of H2 gas. The use of carbon coating as a mitigation strategy and its limitation is also discussed.Graphical abstract

In-Operando Raman Study on the Use of 2D and Suboxide Titanium Host Materials for Lithium-Sulfur Batteries

While Lithium-Sulfur (Li-S) batteries have promised high capacities and low-cost material inputs, their potential has yet to be realized due to inherent issues with sulfur cathodes. In particular the polysulfide shuttle effect and sulfur’s intrinsic insulating properties stand in the way of a commercial battery, the demands of which include high sulfur loading and high cycling stability. Engineering the sulfur cathode, via the use of promising new materials has been an avenue of research pursued in the hopes of mitigating the shuttle effect via polysulfide entrapment and introducing more conductive materials.Of particular interest have been titanium oxide based materials which have shown polysulfide adsorption capabilities. However, the most common titanium oxide, anatase titanium (IV) oxide (TiO2) acts as an insulator, limiting its use in high sulfur loading batteries. Therefore, the use of more conductive titanium oxide materials is an attractive avenue of research. A previously reported freestanding titanium suboxide (TiO) carbon nanofiber cathode demonstrated excellent capacities (~790 mAh/g, ~2 mg/cm2). A rare lepidocrocite phase has also been observed via Raman spectroscopy in a newly discovered titanium carbide derived titanium oxide nanofilament (1D-NF). This material demonstrates properties that makes it attractive as a sulfur host material, having a high surface area of ~1700 m2/g, improved polysulfide reduction kinetics via the formation of polythionates, and polysulfide-cathode host interactions. The inclusion of these nanofilaments in sulfur cathodes yields capacities of ~800 mAh/g with ~1 mg/cm2 sulfur loading.The proposed mechanism via which these titanium oxide based materials function has never been investigated in-operando, and herein we conduct an in-operando Raman study to understand the behavior of these materials. Principally we will investigate the Eg band whose vibration can be moderated by the interaction of terminal sulfur atoms acting as Lewis bases and titanium atoms acting as Lewis acids, due to their vacant valance electrons. This interaction has been observed via postmortem XPS. The use of in-operando Raman allows us to uniquely observe transient behavior of the host material as well as the impact of crystal structure on polysulfide host interactions.

Green chemistry based benign approach for the synthesis of titanium oxide nanoparticles using extracts of AzadirachtaIndica

The colossal significance of nanostructured materials and their implications is a coherent incentive for the exploration of novel conventional techniques. This brings attention to the major problem in developing nanomaterials i.e. the hazardous nature of reactants used. The hazardous reactants are harmful to the environment. So here, biogenic synthesis of nanostructured materials utilizing natural herb extracts has enthralled prodigious implications owing to its rapid, clean, eco-friendly, non-toxic, cost-effective, and as a flipside pathway to several chemical and physiochemical approaches. Titanium oxide materials have been the cynosure for several propitious implications due to their low cost, availability, chemical stability, and biocompatibility. Herein, we developed an efficient green chemistry method for the synthesis of titanium oxide nanoparticles utilizing neem (Azadirachta Indica) extracts. The X-ray diffraction studies revealed the polycrystalline titanium oxide (rutile) structure. The spherical shape of the nanoparticles was observed in TEM and SEM images and their size ranged from 10 to 20 nm. UV–vis studies showed an exciton emission peak at about 380 nm while the IR transmission spectrum revealed the characteristic stretching modes of TiO2. It is envisioned that this novel route for the synthesis of TiO2 nanoparticles could be more beneficial in comparison to other conventional approaches. As the greener approach is being carried out in this paper, therefore, the toxic byproduct is not being released.

Ligand-dependent structural diversity and optimizable CO2 chemical fixation activities of Cu-doped polyoxo-titanium clusters.

Heterometallic oxo clusters have been attracting intensive interest due to their unique properties originating from the synergistic interactions between different components. Herein, we report the construction and catalytic applications of a family of copper-doped polyoxo-titanium clusters (Cu-PTCs) coordinated with different acetate derivative ligands. The solvothermal reactions of metal salts and trimethylacetic acid or 1,2-phenylenediacetic acid in ethanol produced Ti6Cu3(μ3-O)4(μ2-O)(OEt)16(L1)4 (L1 = trimethyl acetate, PTC-367) and H2Ti8Cu2Br2(μ4-O)2(μ2-O)4(OEt)20(L2)2 (L2 = 1,2-phenylenediacetate, PTC-368), respectively. When smaller acetic acid was introduced as a stabilizing ligand, higher nuclei H2Ti16Cu3(μ4-O)5(μ3-O)15(μ2-O)3(OiPr)18(Ac)8 (Ac = acetate, PTC-369) and H3Ti29Cu3(μ4-O)6(μ3-O)30(μ2-O)8(OiPr)17(Ac)20 (PTC-370) were prepared. The number of metal ions exposed on the surface of the four clusters changes due to variations in the steric hindrance of functionalizing ligands, and theoretically, so does their catalytic activity as Lewis acids. In light of this, we conducted a carbon dioxide cycloaddition reaction in an atmospheric environment and the four obtained compounds displayed increasing catalytic activities from PTC-367 to PTC-370. These results provide a feasible synthetic method for modulating the structures of Cu-doped titanium oxide materials and improving their catalytic activities.

Black Titanium-Oxo Clusters with Ultralow Band Gaps and Enhanced Nonlinear Optical Performance.

A series of catecholate-functionalized titanium-oxo clusters (TOCs), PTC-271 to PTC-277, with atomically precise structures were synthesized and characterized, including distinctive "boat" and "chair" conformations in PTC-273 and PTC-274, respectively. These cluster compounds are prominent for their ultralow optical band gaps, as is visually evident from the rather unusual black TOCs (B-TOCs), PTC-272 to PTC-277. The cluster structures were found to be ultrastable with respect to air, water, organic solvents, and even acidic or basic aqueous solutions in a wide pH range (pH 0-13), owing to the stabilizing effects of catecholate and its derivatives, as well as the carboxylate ligands. Another prominent feature is the occurrence of third-order nonlinear optical (NLO) performance, which has previously been unreported in the field of homometallic titanium-oxo clusters. Open-aperture Z-scan experiments show significant solid-state optical limiting (OL) applications of these B-TOCs, with high laser irradiation stability and low minimum normalized transmittance (Tmin) of PTC-273 as ∼0.17. Meanwhile, theoretical calculations indicate that the smaller band gaps of B-TOCs were beneficial for strengthening the NLO response. This work not only represents a significant milestone in the construction of stable low-band gap black titanium oxide materials but also contributes to the mechanism insights into their optical applications.

Controllable synthesis of bifunctional material Ca2Ti2O6:Eu3+ and its comparative study on luminescence and photocatalytic properties with CaTiO3:Eu3+

Pure pyrochlore Ca2Ti2O6, perovskite CaTiO3, and their mixed crystalline phases with different proportions were controllably synthesized via a solvothermal method, followed by a subsequent calcination process. RIR (reference intensity ratio) data of Ca2Ti2O6 were first obtained by X-ray diffraction (XRD), which can be used to quantitatively analyze the phase composition. When Eu3+ is doped into these calcium titanium oxides, they can be used as luminescent and photocatalytic materials. The structure, luminescence, and photocatalytic properties of pure pyrochlore Ca2Ti2O6:Eu3+ and perovskite CaTiO3:Eu3+ were comparatively studied in detail. The relative intensities of the excitation peaks and the emission peaks in Ca2Ti2O6:Eu3+ and CaTiO3:Eu3+ are different, which is attributed to the different symmetries of Eu3+ inhabiting the two kinds of lattices. In addition, although the luminescence intensity of CaTiO3:3%Eu3+ is higher than that of Ca2Ti2O6:3%Eu3+ under excitation at 394 nm, the luminescence intensity of Ca2Ti2O6:3%Eu3+ is superior to that of CaTiO3:3%Eu3+ under excitation at 464 nm and 533 nm. Photocatalytic experiments show that Ca2Ti2O6:3%Eu3+ has better photocatalytic performance than CaTiO3:3%Eu3+, which is mainly due to its smaller crystallite size, higher specific surface area and pyrochlore structure. In addition, biphase (Ca2Ti2O6–CaTiO3):3%Eu3+ has the best photocatalytic activity compared with the single phase Ca2Ti2O6:3%Eu3+ and CaTiO3:3%Eu3+, owing to the presence of heterojunctions that significantly reduced the band gap. It is anticipated that the discovery of this bifunctional Ca2Ti2O6:Eu3+ would expand the application of rare earth-doped calcium titanium oxide materials.

Synthesis and characterization of Fe2O3-TiO2 magnetic materials: Effect of heat-treatment on catalytic activity of naphthalene hydrogenation

We report physicochemical characterization and catalytic evaluation of Fe2O3-TiO2 magnetic materials synthesized at mild conditions, using co-precipitation method with heat-treatment at 673 K, 773 K and 873 K. Results indicate different crystallographic phases including anatase, hematite, rutile and maghemite with a granular morphology, with no uniform grain-size distribution, as confirmed Rietveld Refinement and SEM techniques. High-Resolution Transmission Electron Microscopy (HR-TEM) confirmed presence of stick, spherical and hexagonal nanoparticles. The N2-physisorption and Vibrating Sample Magnetometry (VSM) indicated that Specific Area (SBET) and magnetic remanence response is attributed to calcination temperatures. Diffuse reflectance ultra-violet visible (DR-UV-Vis) and Temperature Programmed Reduction of hydrogen (H2-TPR) showed photoactive species are related to Fe-based content near its surface, with a superficial metallic iron, during hydrogenation process. A different interaction between iron-oxide and titanium oxide materials is linked to lower magnetic remanence, and this could promote catalytic activation with conversion rates near 80% for 1 h of chemical reaction related to 2+ and 3+ oxidation states for Fe and Ti species.

Ion-exchange-induced Bi and K dual-doping of TiOx in molten salts for high-performance electrochemical nitrogen reduction

Electrocatalytic nitrogen reduction reaction (eNRR) at the ambient conditions is attractive for ammonia (NH3) synthesis due to its energy-efficient and eco-friendly features. However, the extremely strong N≡N triple-bonds in nitrogen molecules and the competitive hydrogen evolution reaction lead to the unsatisfactory NH3 yield and the Faradaic efficiency (FE) of eNRR, making the development of high-performance catalysts with adequate active sites and high selectivity essential for further development of eNRR. Addressing this, we herein report a Bi and K dual-doped titanium oxide (BTO@KTO) material, which is prepared by a cation exchange reaction between K2Ti4O9 and molten BiCl3, for high-performance eNRR catalysts. Benefiting from the controllable molten-salt cation exchange process, a highly active surface containing Bi/K sites and rich oxygen vacancies has been obtained on titanium oxide. Under the synergy of these two merits, an efficient eNRR catalysis, with the NH3 yield rate of 32.02 μg h−1 mgcat.−1 and the FE of 12.71%, has been achieved, much superior to that of pristine K2Ti4O9. This work thus offers a high-performance electrocatalyst for eNRR, and more importantly, a versatile cation-exchange strategy for efficiently manipulating materials' functionalities.

Welding technology that saves energy by using electrolysis of a water membrane mixed with titanium oxide and aluminum materials

It is known that the modification of the surface of titanium membranes and its alloys is a hot spot of modern research. In addition, that the use of anodic oxidation is the technology recognized to improve the membranes of titanium used in water welding. Moreover, this use has many problems, especially those bacteria that are formed on the surface of titanium oxide and weaken its functions in welding. Therefore, it tried to mix it with aluminum to improve the properties of the membrane of titanium oxide. It found that the mixture form soft tissue that helped the biological activity and was antibacterial and energy-saving and cost.

Biopolymer and Synthetic Polymer-Based Nanocomposites in Wound Dressing Applications: A Review.

Biopolymers are materials obtained from a natural origin, such as plants, animals, microorganisms, or other living beings; they are flexible, elastic, or fibrous materials. Polysaccharides and proteins are some of the natural polymers that are widely used in wound dressing applications. In this review paper, we will provide an overview of biopolymers and synthetic polymer-based nanocomposites, which have promising applications in the biomedical research field, such as wound dressings, wound healing, tissue engineering, drug delivery, and medical implants. Since these polymers have intrinsic biocompatibility, low immunogenicity, non-toxicity, and biodegradable properties, they can be used for various clinical applications. The significant advancements in materials research, drug development, nanotechnology, and biotechnology have laid the foundation for changing the biopolymeric structural and functional properties. The properties of biopolymer and synthetic polymers were modified by blending them with nanoparticles, so that these materials can be used as a wound dressing application. Recent wound care issues, such as tissue repairs, scarless healing, and lost tissue integrity, can be treated with blended polymers. Currently, researchers are focusing on metal/metal oxide nanomaterials such as zinc oxide (ZnO), cerium oxide (CeO2), silver (Ag), titanium oxide (TiO2), iron oxide (Fe2O3), and other materials (graphene and carbon nanotubes (CNT)). These materials have good antimicrobial properties, as well as action as antibacterial agents. Due to the highly antimicrobial properties of the metal/metal oxide materials, they can be used for wound dressing applications.

Novel TiO2 Nanoparticles/Polysulfone Composite Hollow Microspheres for Photocatalytic Degradation.

Nanosized titanium oxide (TiO2) material is a promising photocatalyst for the degradation of organic pollutants, whereas the difficulty of its recycling hinders its practical application. Herein, we reported the preparation of a novel titanium oxide/polysulfone (TiNPs/PSF) composite hollow microspheres by the combination of Pickering emulsification and the solvent evaporation technique and their application for the photodegradation of methyl blue (MB). P25 TiO2 nanoparticles dispersed on the surface of PSF microspheres. The porosity, density and photoactivity of the TiNPs/PSF composite microsphere are influenced by the TiO2 loading amount. The composite microsphere showed good methyl blue (MB) removal ability. Compared with TiO2 P25, and PSF, a much higher MB adsorption speed was observed for TiNPs/PSF microspheres benefited from their porous structure and the electrostatic attractions between the MB+ and the negatively charged PSF materials, and showed good degradation efficiency. For TiNPs/PSF composite microsphere with density close to 1, a 100% MB removal (10 mg L−1) within 120 min at a catalyst loading of 2.5 g L−1 can be obtained under both stirring and static condition, due to well dispersing of TiO2 particles on the microsphere surface and its stable suspending in water. For the non-suspended TiNPs/PSF composite microsphere with density bigger than 1, the 100% MB removal can be only obtained under stirring condition. The removal efficiency of MB for the composite microspheres retained 96.5%, even after 20 cycles. Moreover, this composite microsphere also showed high MB removal ability at acidic condition. The high catalysis efficiency, excellent reusability and good stability make this kind of TiNPs/PSF composite microsphere a promising photocatalyst for the water organic pollution treatment.

Performance enhancement using TiO2 nano particles in solar still at variable water depth

ABSTRACT The present research paper shows the use of Titanium oxide nanoparticle to enhance the yield of Solar still. Titanium Oxide and black die mixture used as a base paint and find out the performance of the solar still at 20% and 40% weight by weight in a combination of titanium oxide materials and a black die. To check the consequences of water depth on productivity yield, readings were taken at different depth of water like 10 mm, 15 mm, 20 mm. The reading of these experiments has compared with a conventional solar still (CSS) in the same location (Gandhinagar, India, 23.2156°N, 72.6369°E) at the same ambient conditions. The outcome of the experiment shows, at higher water depth productivity of solar still increases up to a certain limit. We find that in comparison with conventional solar still 11–18% and 20–23% increment in productivity with 20% and 40% mixture. Highlight Performance of Passive Solar still, active Solar still and phase change material is studied. Nanomaterials are studied, and Titanium oxide (TiO2) used as a phase change material in Distilling system. Effect of variable water depth and concentration of nanomaterial with paint on productivity yield has been studied. The concentration of 40% (w/v) of TiO2 and black paint offer 23% addition efficiency at a water depth of 10 mm concerning conventional solar still.

Epoxy/polyurethane nanocomposite coatings for anti-erosion/wear applications: A review

Offshore pipelines are vulnerable against erosion/wear deterioration mechanisms that can be controlled through the use of proper surface coatings, such as polymer matrix nano-composite (PMNC) coatings that are well-known for their ease of production, availability and applicability. Epoxy, as a versatile rigid and brittle resin and polyurethane with proper chemical/mechanical properties, are potential candidates to make the matrix of these composites. A combination of these polymers can also enhance the mechanical behaviors, glass transition temperature and flexibility. In addition, the desired coating characteristics, such as adhesion to metal substrate, mechanical properties, erosion/wear resistivity and UV absorbance, can be further improved through the addition of appropriate nanoparticles within the polymer matrix. Especially, nanoparticles can improve the erosion/wear resistance of polymers because of establishing high strength bonds between the polymer chains and the reinforcements besides enhancing other required properties. The present work is a review on PMNC coatings that contain epoxy, polyurethane or EP/polyurethane as a polymer matrix along with the details of the nanoparticle reinforcements, such as alumina, silica, titanium oxide, zinc oxide, clay and carbon-based materials. The effect of these nanoparticles on the properties of composite coatings has also been investigated.

Successive redox-mediated visible-light ferrophotovoltaics

Titanium oxide materials have multiple functions such as photocatalytic and photovoltaic effects. Ferroelectrics provide access to light energy conversion that delivers above-bandgap voltages arising from spatial inversion symmetry breaking, whereas their wide bandgap leads to poor absorption of visible light. Bandgap narrowing offers a potential solution, but this material modification suppresses spontaneous polarization and, hence, sacrifices photovoltages. Here, we report successive-redox mediated ferrophotovoltaics that exhibit a robust visible-light response. Our single-crystal experiments and ab initio calculations, along with photo-luminescence analysis, demonstrate that divalent Fe2+ and trivalent Fe3+ coexisted in a prototypical ferroelectric barium titanate BaTiO3 introduce donor and acceptor levels, respectively, and that two sequential Fe3+/Fe2+ redox reactions enhance the photogenerated power not only under visible light but also at photon energies greater than the bandgap. Our approach opens a promising route to the visible-light activation of photovoltaics and, potentially, of photocatalysts.

Realizing the Single-Phase Spinel-Type Sodium Titanium Oxide with the Li4Ti5O12-like Structure for Building Stable Sodium-Ion Batteries.

Sodium titanium oxide with a spinel-type structure is suitable for the stable sodium-intercalation host for the negative electrode of sodium-ion batteries, such as the spinel-type lithium titanium oxide (Li4Ti5O12, LTO) material for lithium-ion batteries. Recently, this has been partly discovered as the Na3LiTi5O12 (NTO) phase in the LTO particle. However, the single-phase NTO material has never been obtained, preventing accurate material characterizations and applications. Here, we successfully realized the NTO material with the single-phase by the chemical sodium insertion-extraction process. The chemical sodium-inserted LTO material is well converted to the pure NTO phase in the single particle level, via following chemical oxidation by water. The purified material was about 97 mol % of NTO as the single-phase spinel structure with a = 8.746 Å. The basic lattice framework of the prepared NTO was confirmed to be the same as that of the LTO. The single-phase NTO electrode shows 0.8 V versus Na+/Na of the Na-insertion and extraction potential, and 99.4% of Na-insertion capacity with 99.7% of Coulombic efficiency during 200 cycles of the Na-ion half-cell experiment. Further, the Na2Fe2(SO4)3/NTO full-cell shows 3 V-class stable charge-discharge character during 100 cycles. This excellent stability of Na-insertion and extraction properties of single-phase NTO extends the range of constructing safe and stable high-voltage oxide-based sodium-ion battery cells for practical use.

Carbon-modified titanium oxide materials for photocatalytic water and air decontamination

Titanium oxide-based materials with different physical and chemical features were synthetized aiming at removing organic pollutants from both water and air media. The materials were produced employing two different heating methodologies (thermal, T and hydrothermal, H) at distinct temperatures resulting in porous materials. These materials were also modified with either graphene oxide (GO) or carbon nanotubes (CNT), using an in-situ approach. All materials were tested as photocatalysts using ultra-violet (UV), visible (Vis) and solar radiation. Rhodamine B (RhB) and benzene were used as representative pollutants in water and air, respectively.The addition of carbon to the catalysts improved the removal of both pollutants. In the case of the photocatalytic degradation of rhodamine B, under both UV and Vis light, it was found that, the materials containing carbon nanostructures allowed the highest degradation degree, while the photosensitisation phenomenon became negligible. The best catalyst is the one containing CNT (2.98 wt% of C) and thermally treated at 300 °C (T300_CNT). This material showed higher degradation ability than the commercial TiO2 nanopowder Degussa P25 (P25) under Vis light. Regarding benzene removal, the samples thermally treated at 300 °C and modified with CNT and GO (T300_CNT and T300_GO, respectively) outperformed Degussa P25. The former material was successfully reused in the photocatalytic degradation of benzene over 6 consecutive cycles.

Amino-Polyalcohol-Solvothermal Synthesis of Titanium-Oxo Clusters: From Ti6 to Ti19 with Structural Diversity.

As is known, amino-polyalcohol ligands are usually used as sacrificial agents in photocatalytic reactions. And polyoxo-titanium clusters (PTCs) are molecular modes of titanium dioxide, one of the most important photocatalysts. In order to help understand the intrinsic coordination feature of amino-polyalcohol toward titanium-oxo species, we carried out the research of constructing PTCs with amino-polyalcohol ligands. In view of the low melting point of amino-polyalcohol, they have been directly applied as reaction mediums. Under this new synthetic method, a series of PTCs have been successfully obtained, namely, Ti6(μ2-O)2(OCH2CH2O)2(O iPr)4(dea)6·HO iPr (deaH2 = diethanolamine, PTC-171), Ti9(μ2-O)2(μ3-O)4(tea)2(O iPr)8(dea)5(teaH3 = triethanolamine, PTC-172), Ti11(μ3-O)10(μ4-O)(O iPr)14(dea)4 (PTC-173), Ti19(μ2-O)6(μ3-O)12(dea)18Cl4 (PTC-174), and Ti19(μ2-O)6(μ3-O)12(dea)18(NO3)4·(H2O)6 (PTC-175). Their structures are determined by single-crystal X-ray diffraction analysis. It is worth noting that PTC-174 and PTC-175 are not only the first Ti19 examples of crystalline PTCs, but also currently the largest PTCs compounds in the amino-polyalcohol system. Moreover, the solid-state UV-vis spectra of these PTCs were recorded. And their applications in photocurrent responses were also investigated. This work provides an interesting method for the preparation of amino-polyalcohol base PTCs and would also benefit the mechanism interpretation of the photocatalytic processes of titanium oxide materials.

Isomerism in Titanium-Oxo Clusters: Molecular Anatase Model with Atomic Structure and Improved Photocatalytic Activity.

Phase isomerism is a common and important phenomenon in inorganic materials, but the molecular isomerism of their nanocluster models is still rare. In this work, we report the first pair of isomeric titanium-oxo clusters. Through combining pentagonal {Ti(Ti5 )} building units in corner-sharing or edge-sharing forms, the two obtained Ti20 -oxo clusters take vertical and horizontal core configurations, respectively, which are both functionalized by the same organic ligands. More interestingly, the vertical type Ti20 -oxo core contains an identical {Ti8 O14 } moiety as anatase, making it the first molecular model of anatase TiO2 . As a result, the vertical type cluster exhibits better photocatalytic H2 evolution activity, higher photocurrent response and faster charge transfer to external acceptors than its horizontal isomer. Thus, this work provides a cluster isomer method to understand the structure-property relationship of import titanium oxide materials.

Isomerism in Titanium‐Oxo Clusters: Molecular Anatase Model with Atomic Structure and Improved Photocatalytic Activity

AbstractPhase isomerism is a common and important phenomenon in inorganic materials, but the molecular isomerism of their nanocluster models is still rare. In this work, we report the first pair of isomeric titanium‐oxo clusters. Through combining pentagonal {Ti(Ti5)} building units in corner‐sharing or edge‐sharing forms, the two obtained Ti20‐oxo clusters take vertical and horizontal core configurations, respectively, which are both functionalized by the same organic ligands. More interestingly, the vertical type Ti20‐oxo core contains an identical {Ti8O14} moiety as anatase, making it the first molecular model of anatase TiO2. As a result, the vertical type cluster exhibits better photocatalytic H2 evolution activity, higher photocurrent response and faster charge transfer to external acceptors than its horizontal isomer. Thus, this work provides a cluster isomer method to understand the structure–property relationship of import titanium oxide materials.