Rutile Titanium Research Articles

Effective transformation of hydrothermally grown TiO2 nanorods to nanotube arrays for improved PEC hydrogen evolution

Innovative green and renewable energy solutions to achieve carbon neutrality could be achieved using advanced functional materials. For the commercial realization of PEC water-splitting technology, low-cost, high active surface area, and high-performance catalyst is required. To do so, engineering the structure of the catalyst, controlling morphology and synthesis method becomes essential. So herein insightful design of experiments was carried out to synthesize in-situ growth of facet-controlled, vertically oriented rutile titanium dioxide (TiO2) nanorod (TNR) arrays and subsequent conversion to nanotubes (TNT) arrays using a facile hydrothermal approach. The photoelectrochemical (PEC) measurements at 1.23 V vs. RHE reveal a high photocurrent density of 976.8 µA cm−2 and a high theoretical H2 production of 7.4 µl min−1 cm−2 for FTO-grown TNTs. The increased exposed active surface area, improved light penetration, and uniformly oriented structures are responsible for higher response of TNTs over TNRs. Thus, present study offers a one-step conversion of nanorods to nanotubes and the corresponding improvement in PEC performances.

Rutile titanium dioxide and graphene-like OCN tailoring free-standing carbon fiber aerogel as polysulfide anchoring materials for lithium–sulfur batteries

The rational design of a host material with strong adsorption and excellent electrical conductivity function for sulfur cathode to suppress the shuttle effects of soluble lithium polysulfide (LiPS) is crucial to advance the lithium–sulfur (Li–S) battery for future commercial applications. In this work, we designed a three-dimensional (3D) carbon fiber aerogel with graphene-like oxygenated carbon nitrogen (OCN) and TiO2 (OCNF–TiO2) as a sulfur anchoring material for Li–S battery and explored the regulating effects of TiO2 on the electrochemical performances. The OCNF–TiO2/S cathode presents an initial discharge-specific capacity of 1039 mAh/g (0.1C), a rate capacity of 690 mAh/g at 1C, a cycling performance with a capacitance retention of 72.1%, and the decay of 0.13% per cycle after 200 cycles at 0.5C.

Synthesis of Carbon – TiC/TiB2 Composites at the Electrolytic Reduction of Fused Salts

This article presents the results of laboratory testing of the technology for the synthesis of composite carbon—titanium carbide/titanium diboride (C—TiC/TiB 2) material directly in course of electrolytic reduction of cryolite-alumina melts. After the preliminary standard treatment purposing the mixing of initial components—petroleum coke of different fractions, rutile titanium oxide TiO 2, boron oxide B 2 O 3 and binding agent—the cathode specimens were pressed to the specified sizes and thermally treated at the temperature of 1050 °С. Experiments with holding time of 5, 15 and 24 h during the electrolytic reduction process have demonstrated the acceptable wettability of cathode specimen surface. X-ray phase analysis and SEM-EDS-analysis have detected the presence of TiC/TiB 2 and titanium oxycarbide TiC x O 1-x within the volume of cathodes and on their surface. After 15 and 24 h experiments the aluminium layer with good adhesion to the surface was noticed on the cathode surface; which is indicative of wettability of the electrode with metal. This tested technology can be extended to the creation of wide range of composite products in the С—МеС/МеВ 2 system.

Tip-activated single-atom catalysis: CO oxidation on Au adatom on oxidized rutile TiO2 surface.

Single-atom catalysis of carbon monoxide oxidation on metal-oxide surfaces is crucial for greenhouse recycling, automotive catalysis, and beyond, but reports of the atomic-scale mechanism are still scarce. Here, using scanning probe microscopy, we show that charging single gold atoms on oxidized rutile titanium dioxide surface, both positively and negatively, considerably promotes adsorption of carbon monoxide. No carbon monoxide adsorption is observed on neutral gold atoms. Two different carbon monoxide adsorption geometries on gold atoms are identified. We demonstrate full control over the redox state of adsorbed gold single atoms, carbon monoxide adsorption geometry, and carbon monoxide adsorption/desorption by the atomic force microscopy tip. On charged gold atoms, we activate Eley-Rideal oxidation reaction between carbon monoxide and a neighboring oxygen adatom by the tip. Our results provide unprecedented insights into carbon monoxide adsorption and suggest that the gold dual activity for carbon monoxide oxidation after electron or hole attachment is also the key ingredient in photocatalysis under realistic conditions.

Preparation and properties of thermal insulation coating based on silica aerogel

An environmentally friendly coating with excellent thermal insulation ability has been investigated in this paper. It uses styrene-acrylic latex as the film-forming material, silica aerogel (SA), hollow glass beads, rutile titanium dioxide, sericite powder as fillers. Combined with other additives, it is prepared by joint mixing. This coating uses water as a solvent. It does not add other organic solvents. Therefore, it is non-toxic and harmless to the environment and human body. Through a series of test studies on the coating after drying, it can be found that the coating meets the requirements of use. When the temperature of the heated surface of the coating with a thickness of 4 ± 0.2 mm is 351℃, the temperature of the back-heated surface is only 188℃, a difference of 163℃, which is a significant thermal insulation effect. In addition, the heat resistance, water resistance, corrosion resistance, wear resistance, etc. are improved with the addition of SA. All in all, the SA can improve the properties of some coatings. However, the study found that the SA is not the more the better, and the amount should be controlled within a certain range.

Construction of R-TiO2/n-TiO2 heterophase photocatalysts for efficient degradation of organic pollutants

In this study, a commercial rutile titanium dioxide (R-TiO2) with a particle size of 200–300 nm was used as a carrier to prepare R-TiO2/n-TiO2 photocatalysts through wet co-grinding in a stirred grinder, along with commercial TiO2 (n-TiO2). The structure of R-TiO2/n-TiO2, its photocatalytic degradation performance towards methyl orange, and the enhancement mechanism were investigated. The results demonstrated that under the optimized conditions of grinding time and n-TiO2 loading ratio, the prepared R-TiO2/n-TiO2 composite (with a n-TiO2 ratio of 30%) exhibited excellent photocatalytic degradation and recyclability. After 30 min of UV irradiation, the removal rate of methyl orange was 99%, which was comparable to that of pure n-TiO2 (degradation rate of 99.5%). The degradation rate of methyl orange using R-TiO2/n-TiO2 was 4.5 times higher than that of an equivalent proportion of n-TiO2, and the degradation performance remained nearly unchanged after five cycles of recycling. R-TiO2/n-TiO2 exhibits features such as effective dispersal and even distribution of n-TiO2 onto the surface of R-TiO2, coupled with the establishment of chemical bonding at the interface between the two constituents. The existence of R-TiO2 improved the dispersion of n-TiO2 and promoted the formation of an interfacial anatase/rutile heterophase junction, which are intrinsic mechanisms for enhancing the efficiency of TiO2 photocatalysis and achieving a reduction in the application process.

Enhanced Electrochemical Performance of NTP/C with Rutile TiO2 Coating, as Anode Material for Sodium‐Ion Batteries

AbstractNaTi2(PO4)3 (NTP) is known as a promising insertion‐type anode material for aqueous and non‐aqueous sodium‐ion batteries (SIBs), due to its NASICON‐type open 3D framework which makes a zero‐strain insertion mechanism possible. NTP is considered to be an environmentally friendly, low‐cost and high safety material. However, the electrochemical performance of NTP is limited due to its poor electrical conductivity. In this work a solvothermal synthesis method is used to synthesize NTP with a nanocube (NC) morphology. In a one‐step synthesis rutile titanium dioxide (TiO2) and carbon coating of NTP are achieved (NTP/C‐RT), simultaneously, which significantly improves the poor electrical conductivity of NTP. Additional rutile coating is used to further improve the electrochemical performance compared to simple carbon coating. Rate capabilities of 301 mAh/g are achieved for NTP/C‐RT compared to 248 mAh/g for NTP/C at 0.1 C. That is, to the best of our knowledge, the highest gravimetric capacity reported for SIBs using NTP as anode material up to now. The results prove that NTP, which is itself already a promising anode material for SIBs, can be further enhanced with a combined approach of NC morphology, carbon and rutile coating, leading to superior capacities, higher than anywhere else reported in literature.

Interaction of biomolecules with anatase, rutile and amorphous TiO2 surfaces: A molecular dynamics study.

The adhesion of biomolecules to dental and orthopedic implants is a fundamental step in the process of osseointegration. Short peptide motifs, such as RGD or KRSR, carried by extracellular matrix proteins or coated onto implant surfaces, accelerate cell adhesion and tissue formation. For this reason, understanding the binding mechanisms of adhesive peptides to oxidized surfaces of titanium implants is of paramount importance. We performed molecular dynamics simulations to compare the adhesion properties of 6 peptides, including the tripeptide RGD, its variants KGD and LGD, as well as the tetrapeptide KRSR, its variant LRSR and its truncated version RSR, on anatase, rutile, and amorphous titanium dioxide (TiO2) surfaces. The migration of these molecules from the water phase to the surface was simulated in an aqueous environment. Based on these simulations, we calculated the residence time of each peptide bound to the three different TiO2 structures. It was found that the presence of an N-terminal lysine or arginine amino acid residue resulted in more efficient surface binding. A pulling simulation was performed to detach the adhered molecules. The maximum pulling force and the binding energy were determined from the results of these simulations. The tri- and tetrapeptides had slightly greater adhesion affinity to the amorphous and anatase structure than to rutile in general, however specific surface and peptide binding characters could be detected. The binding energies obtained from our simulations allowed us to rank the adhesion strengths of the studied peptides.

Thermochemical Cyclization Forms Core-Shell Structured Rutile TiO2@C-PAN as an Advanced Anode for Lithium-Ion Batteries

Rutile TiO2 is a prospective lithium-ion anode material, which has the advantages of small volume change and excellent cycling performance. The low theoretical capacity and poor conductivity, however, prevent further application. In this work, we proposed a thermochemical cyclization coating strategy and successfully prepared rutile titanium dioxide anode material coated with conductive polymer Polyacrylonitrile (PAN). The coated material has an initial capacity of 246.5 mAh/g and a stable capacity of 125.5 mAh/g after 100 cycles. It is worth noting that this simple and effective coating method will contribute to the further application of rutile TiO2 materials.

Assessing the formation and destruction behaviors of fine powder agglomerates in vibrating fluidized beds using the Ergun equation

The recycling and reutilization of powdery/dust waste are becoming increasingly important for ensuring a sustainable environment and decreasing the cost of waste disposal. In this regard, we examined component separation using a vibrating fluidized bed based on the differences in the agglomeration properties of the particles of each component. In the proposed separation method, the knowledge of agglomerate formation and destruction in a fluidized bed is essential. In this study, the effects of particle properties on agglomerate formation and destruction in a vibrating fluidized bed were investigated. Rutile and anatase titanium oxide and zinc oxide were used as test powders. The changes in the powder layer height and pressure drop were recorded. The results were utilized to compute the changes in the agglomerate size using the Ergun equation, and agglomerate formation and destruction were evaluated. Furthermore, the relationship between the equilibrium agglomerate size and vibration intensity was investigated.

Photocatalytic performance of nitrogen-doped titanium dioxide nanostructures prepared by sol-gel method

A sol-gel method was used to prepare nitrogen-doped titanium dioxide nanoparticle using tetrabutyl titanate as the titanium source and urea as the nitrogen source. The structure and properties of the samples were characterized by modern testing methods. The photocatalytic performance of N-doped titanium dioxide nanoparticle was evaluated by taking Polyacrylic amide (PAM) in the wastewater from petroleum extraction as the target degradation product. The results show that, after N-nano TiO2 is calcined at 650 °C, the TiO2 is mainly of anatase type, with a large amount of rutile titanium dioxide nanoparticle between the crystals, and the average grain size decreases from 25.9 nm to 16.8 nm. Under visible light, the removal rate of N-TiO2 on PAM simulated wastewater for 3 h was determined to have been 59% and this is increased to 79.8%. After the photocatalyst was regenerated by ultraviolet irradiation, the removal rate of pollutants still reached 74.2%.

Insights on the role of particulate filler on the polymer-modified cement-based coating and its application

The correct use of particulate fillers is the key to improving the functionality and durability of polymer-modified cement-based coatings. In this study, the amount and ratio of flake waste glass powder and rutile titanium dioxide (TiO2) were designed based on the theory of pigment volume concentration (PVC)/critical pigment volume concentration (CPVC). The tensile property, thixotropy, water absorption, microstructure and anti-ultraviolet light (UV) aging of the coatings were comprehensively studied. The results showed that when the amount of filler was 20 wt% and ratio was 2:1 (PVCCPVC), the tensile strength of the coatings increased by 49% and the water absorption reduced by 15%, accompanied by the good thixotropy. The reason was attributed to the denseness and integrity of the coatings microstructure due to the interaction between the polymer film, inorganic fillers and cement hydrates. Furthermore, the addition of rutile TiO2 could enhance the anti-UV aging property of the coatings by reducing the effect of UV light on the organic components. Moreover, the durability of fabricated coatings was substantially better than commercially available coatings in practical applications.

Получение частиц диоксида титана (рутила) на поверхности восстановленного оксида графена в сверхкритическом изопропаноле

Sequential synthesis of rutile modification titanium oxide particles on reduced graphene oxide in supercritical isopropanol is described. In this case, only graphene oxide was reduced to reduced graphene oxide. A one-stage method (one-pot) was also developed for the preparation of rutile particles on reduced graphene oxide, where supercritical isopropanol was the graphene oxide reducing agent and the reaction medium. The resulting composites were studied using X-ray phase analysis, transmission electron microscopy, and atomic force spectroscopy methods.

Fungal Colonization of Weathered Radiata Pine Surfaces Protected with Inorganic Nanoparticles and Coatings

Photoactive nanoparticles are used to reduce microbial colonization and self-clean surfaces of materials such as glass and ceramics. To test whether such an approach is feasible for wood surfaces, we treated radiata pine samples with TiO2 (rutile and anatase) or ZnO nanoparticles and then coated the samples with different finishes. Coated samples and uncoated controls were exposed outdoors for six months. After exposure, fungi colonizing wood surfaces were identified using molecular techniques and microscopy, and colour changes in the wood samples were also measured. Treatment of uncoated surfaces with nanoparticles reduced the discolouration of wood during weathering but had little effect on colonization of wood by black mould fungi. In contrast, pretreatment of samples with titanium dioxide nanoparticles increased the number and diversity of fungi including basidiomycetes colonizing coated samples, whereas zinc oxide nanoparticles had the opposite effect. Zinc oxide nanoparticles, however, were less effective than rutile titanium dioxide nanoparticles at reducing the discolouration of coated samples exposed to natural weathering. We conclude that none of the photoactive nanoparticles on their own are able to reduce microbial colonization and discoloration of samples. This suggests that it may be difficult to create self-cleaning wood surfaces using photoactive nanoparticles.

Mechanistic aspects of the reduction of rutile titanium dioxide and its Re-oxidation. Development and destruction of crystallographic shear structures

A model is presented giving the mean dimensions of acicular octadecahedral microcrystallites of a rutile titanium dioxide powder. Reduction at 823 K, in conjunction with ESR, electrical conductivity and controlled re-oxidation has enabled the model to be applied to reduced microcrystallites. At 300 K they contain <0.1% of paramagnetic [Ti3+↑ VO:↑Ti3+] reduced edge sites and >99.9% of reduced spin-paired [Ti3+↑↓ Ti3+ VO:] sites. These sites are situated on the external crystal faces and on polygonal bulk crystallographic shear (CS) structures inclined to the microcrystal four-fold symmetry axis. CS structures are quantum-sized [Ti4O7VO:] environments which broaden the paramagnetic signals at 78 K. Temperature programmed reduction in H2(g) reveals atomic hydrogen as a precursor to CS structure formation via a lattice template formed on microcrystallite faces. Shear structures are oxidised on their polygonal perimeters at differing rates on the respective microcrystallite faces by anionic vacancy transfer from sub-surface regions.

Preparation and Performance Characterization of an Active Luminous Coating for Asphalt Pavement Marking

For improving the night recognition of road markings and enhancing the driving safety of asphalt pavements, single-factor optimization is used to investigate the effects of the component materials, including luminescent power, pigment, filler, and anti-sedimentation agent, on the luminous performance of a coating. Additionally, their composition ratios are optimized using response surface methodology. A phosphorescent marking coating is prepared to investigate the micromorphology, excitation, and emission properties using scanning electron microscopy (SEM) and molecular fluorescence spectroscopy (MFS). The optimum thickness of the coating on an asphalt pavement is investigated, and the durability of the coating on asphalt pavement using a wheel rutting test is evaluated. The results show that the 300 mesh yellow-green luminous powder has the optimal overall performance, with an initial luminescence that exceeds that of orange and sky blue by three times. Initial brightness is mainly influenced by aluminate luminescent powder (ALP), which increases with the dosage. ALP and fumed silica powder (FSP) have a positive effect on brightness after centrifugation, and the effect of FSP dosage is more significant. ALP, rutile titanium dioxide powder (RTDP), and FSP influence the wear value of the coating, and the magnitude of the effect is RTDP &gt; FSP &gt; ALP. The optimal dosages of the main component are 27% ALP, 5% RTDP, and 0.8% FSP. The results of SEM show that the components in the coating are evenly dispersed, and the surface of the coating is rough. The peak excitation wavelength of 420 nm means that the coating has the best excitation effect in UV light, and its emission spectrum in the 440–760 nm wavelength range is well within the sensitive recognition zone of the human eye. The initial brightness gradually reached 4.38 cd/m2 when the coating thickness was increased from 482 μm to 546 μm, and the optimal application thickness of the luminous coating was determined to be 500 μm. At high and normal temperatures, the rutting stripping rates of the luminous marking coating are 16.8% and 8.2%, indicating its satisfactory durability. This study provides an experimental basis for the ratio optimization design of a luminous coating for asphalt pavements.

Fabrication of nanostructured non-stoichiometric TiO2-x by spark plasma sintering for enhancing its thermoelectric properties

In this study, nanostructured non-stoichiometric TiO2-x compacts were prepared by the in-situ reduction of rutile titanium oxide (TiO2) powder with urea powder via spark plasma sintering (SPS). The crystal structure and particle size of the prepared compacts were examined. The XRD patterns revealed that TiO2 could be reduced easily by the urea powder to obtain non-stoichiometric TiO2-x, and the compacts still possessed rutile crystal structures. The average particle sizes of the compacts were less than 250 nm, successfully obtaining the non-stoichiometric TiO2-x with uniform nanostructures at the sintering temperature of 1073 K. In addition, nanostructured TiO2-x compacts with Magnéli phase TinO2n-1 (n = 2, 4, 8) were fabricated by varying the volume fraction of Ti powder in a urea environment via SPS. The results suggested that addition of Ti powder contributed to the formation of Magnéli phases TinO2n-1, and the value of n decreased with an increase in the volume fraction of the Ti powder. Furthermore, the thermoelectric properties of the compacts sintered with and without Ti powder were both investigated. The TiO2–U13.3-Ti10 compact displayed the highest power factor of 5.04 μWcm−1K−2 at 973 K. A lower thermal conductivity was achieved by TiO2–U13.3-Ti10 compact in the temperature range of 373–973 K, approximately 3 Wm−1K−1, due to the nanostructures and Magnéli phases. The highest ZT value of 0.146 was obtained for the TiO2–U13.3-Ti10 compact at 973 K, achieving a reasonable enhancement of thermoelectric properties.

Cost-effective dye-sensitized solar cells based on rutile-phase three-dimensional TiO2 hierarchical nanostructures.

Specifically engineered three-dimensional (3D) and 1D morphologies are expected to play significant roles in the development of next-generation dye-sensitized solar cells. In this study, using a hydrothermal approach without a surfactant or template, we attempted to synthesize a 3D hierarchical rutile titanium dioxide (TiO2 ) architecture by varying the growth temperature and time. X-ray diffraction patterns of the synthesized TiO2 correlated well with rutile TiO2 . Scanning electron microscopy images exhibited different nanostructures, such as nanorods, aggregated nanorods, and 3D TiO2 microflowers comprised of nanorods at 100°C, 130°C, and 160°C, respectively, after growth for 6 h. A significantly improved efficiency was observed for the TiO2 microflowers. The TiO2 microflowers exhibited an efficiency of 1.16%, short-circuit current density of 12.8 mA cm-2 , open-circuit voltage of 0.692 V, and fill factor of 0.67.

Investigation of Adverse Reactions in Tattooed Skin through Histological and Chemical Analysis

Background: Just as the number of tattooed people has increased in recent years, so has the number of adverse reactions in tattooed skin. Tattoo colourants contain numerous, partly unidentified substances, which have the potential to provoke adverse skin reactions like allergies or granulomatous reactions. Identification of the triggering substances is often difficult or even impossible. Methods: Ten patients with typical adverse reactions in tattooed skin were enrolled in the study. Skin punch biopsies were taken and the paraffin-embedded specimens were analysed by standard haematoxylin and eosin and anti-CD3 stainings. Tattoo colourants provided by patients and punch biopsies of patients were analysed with different chromatography and mass spectrometry methods and X-ray fluorescence. Blood samples of 2 patients were screened for angiotensin-converting enzyme (ACE) and soluble interleukin-2 receptor (sIL-2R). Results: Histology showed variable skin reactions such as eosinophilic infiltrate, granulomatous reactions, or pseudolymphoma. CD3+ T lymphocytes dominated the dermal cellular infiltrate. Most patients had adverse skin reactions in red tattoos (n = 7), followed by white tattoos (n = 2). The red tattooed skin areas predominantly contained Pigment Red (P.R.) 170, but also P.R. 266, Pigment Orange (P.O.) 13, P.O. 16, and Pigment Blue (P.B.) 15. The white colourant of 1 patient contained rutile titanium dioxide but also other metals like nickel and chromium and methyl dehydroabietate – known as the main ingredient of colophonium. None of the 2 patients showed increased levels of ACE and sIL-2R related to sarcoidosis. Seven of the study participants showed partial or complete remission after treatment with topical steroids, intralesional steroids, or topical tacrolimus. Conclusions: The combination of the methods presented might be a rational approach to identify the substances that trigger adverse reactions in tattoos. Such an approach might help make tattoo colourants safer in the future if such trigger substances could be omitted.

Preparation of Iron Phosphate Battery Materials from Industrial Ferrous Sulfate Waste by Liquid Phase Method

Sulfuric acid method is a critical method to prepare rutile and anatase titanium dioxide. In the preparation process, acid leaching is accompanied by a large amount of iron-containing solid waste, represented by ferrous sulfate waste. If these solid wastes are stored directly without proper treatment, they will cause massive environmental damage and a lot of iron resources waste. The impurity removal and high added value utilization of ferrous sulfate had been studied deeply. Based on those studies, separation impurities from ferrous sulfate waste with various phosphate radical precipitation separation method was further explored. And a new process of preparing iron phosphate (FePO4) electrode material by liquid phase precipitation method was proposed to recover Fe from solid waste. Results showed that recovery of Fe in solid waste achieved 92%; moreover, removal rates of Ti, Mg, and Mn are higher than 95.3%, 78.4%, and 89.2%, respectively. The prepared iron phosphate reached the industrial battery grade (HG/T 4701-2014) standard by liquid phase reaction. The process realized efficient recovery of iron from solid waste and high value-added utilization of iron-containing solid waste.