Titanium Hydroxide Research Articles

Titanium oxide hydrates as versatile polymer crosslinkers and molecular‐hybrid formers

AbstractMolecular hybrid materials based on widely available polymers crosslinked with an inorganic species have received increasing interest for their unique property sets outside of the usual range of commodity plastics and/or nanocomposites. Here, we provide a mini‐review on molecular hybrids based on metal oxide hydrates—compounds that readily react with, for example, hydroxylated polymers to form inorganic:organic materials systems with many desirable features and properties. Focusing on titanium oxide hydrates, we discuss here that such molecular hybrids can exhibit a broad refractive index range in addition to an increased glass transition temperature, mechanical stiffness and swelling resistance in comparison to the neat polymer, which illustrates that such hybrid systems offer a new, low‐cost, robust and versatile functional materials platform with great promise for, for example, solution‐processed photonics, catalysts and antimicrobial coatings. Generally, our mini‐review seeks to provide a concise and accessible overview of titanium oxide hydrate:polymer hybrid systems, focusing on their unique properties and processability as well as their broad and largely untapped potential as functional materials. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

General classification and nomenclature of sedimentary deposits and rocks, a review

A new general and genetic classification is proposed that can be applied to sedimentary deposits and rocks (sedimentites), in six main groups depending on the processes that originate them, this classification seeks the standardization and systematization of the criteria and the most used terms, and proposes some new terms: (1) detrital sedimentites formed by fragmentation of rocks “in situ”; (2) clastic sedimentites formed by erosion, transport and sedimentation of solid materials; (3) biogenic sedimentites formed by biological productivity and activity “in situ”; (4) chemical sedimentites formed by crystal precipitation from solutions “in situ” within the basin; (5) mixed sedimentites, those formed by mixed sedimentary processes, e.g., biogenic accumulation and clastic sedimentation, among others; and (6) diagenetic modification-transformation sedimentites, entities formed “in situ” by compaction- reorganization, alteration-transformation, dissolution-collapse, precipitation-cementation, crushing and grinding, or deformation-remobilization processes. Additionally, a new compositional-mineralogical classification of the sedimentites in eleven groups are proposed: silicate; carbonate; phosphate; iron, manganese, aluminum and titanium oxides and hydroxides; sulfate and salts; organic rich; nitrate; sulphide; borate; native rich (metals and the non-metals); and mixed. This systematization offers the advantage of allowing a better and easier sequencing of the classification of the sedimentites and facilitates the improvement in the teaching and learning processes. This systematization offers the advantage of allowing a better and easier sequencing of the classification of sedimentary deposits and rocks and facilitates the improvement in the teaching and learning processes.

Unravelling the nature differences of halide anions affecting the sorption of U(VI) by hydrous titanium dioxide supported waste polyacrylonitrile fibers in the presence of carbonates

The co-occurrence of halides and carbonates with uranium in the natural water poses a challenge to the uranium recovery for nuclear power due to the potential complexation. Hydrated titanium dioxide (HTD) contains a lot of surface hydroxyl (–OH) groups and waste polyacrylonitrile fiber (WPANF) has the advantages of both weather and chemical resistances. Herein, the nature differences of halide anions affecting the sorption of U(VI) by WPANF/HTD was investigated in the presence of carbonates. The sorption capacity (qe) decreased with the increases of initial pH, total carbonates, and halides but increased at high temperature and initial U(VI) concentration. The U(VI) sorption was a spontaneous chemisorption, which mainly involved surface sorption rather than intra-particle diffusion. The order of inhibitory ability on U(VI) sorption for the four halides was F > I ∼ Br > Cl. The aqueous F− was shown to be the most strongly inhibited with the lowest qe value of 17.2 mg·g−1, due to the formation of U(VI)–F complex anions. The characteristic peaks with weakened relative intensity after U(VI) sorption for the surface –OH groups on HTD (HTD–OH), together with the results from DFT calculations, demonstrated a key role of HTD–OH in U(VI) sorption by WPANF/HTD via the coordination with U(VI) complex anions. This work unravels the nature differences of halide anions affecting U(VI) sorption in the presence of carbonates and provides a valuable reference for the U(VI) extraction toward halogen-rich natural uranium-containing water.

Mechanism of Binding of Hydrated Titanium Dioxide Nanocluster with Calcium Aqua Ion

Mechanism of Binding of Hydrated Titanium Dioxide Nanocluster with Calcium Aqua Ion

Hydrolyzed Hydrated Titanium Oxide on Laser-Induced Graphene as CDI Electrodes for U(VI) Adsorption.

Recently, laser-induced graphene (LIG), which has been successfully applied in CDI technology (directly without a complex preparation process), has gained considerable attention. However, the raw LIG electrode with a limited number of active sites exhibits low adsorption efficiency. Therefore, the search for a suitable and effective method to modify LIG to improve its electroadsorption performance is significant. Herein, a very simple titration hydrolysis method is adopted to modify LIG, resulting in a layer of hydrated titanium oxide (HTO) being synthesized on the surface of LIG. The LIG/HTO composites possess a good adsorption property since covering the surface of LIG with a layer of HTO can greatly improve the adsorption capacity of LIG. Moreover, with the addition of HTO, not only the proton transfer ability of LIG has been enhanced but also considerable specific capacitance has been enlarged. As a result, LIG/HTO composite as CDI electrode displays a maximum theoretical adsorption capacity of 1780.89 mg/g at 1.2 V, and the capacitance of LIG/HTO composite material is 4.74 times higher than LIG. During the electroadsorption process, Ti4+ is reduced to Ti3+ under external voltage, and O2- is produced through oxidation. Meanwhile, part of the U (VI) is hydrolyzed into UO3·2H2O under the action of -OH, and some combine with O2- to produce UO4·4H2O.

A sensitive method to determine 210Po and 210Pb in environmental samples by alpha spectrometry using CuS micro-precipitation

A new sensitive method to determine polonium-210 (210Po) and lead-210 (210Pb) in a diversity of environmental samples was developed. For fresh and marine waters, Po was pre-concentrated using a titanium (III) hydroxide (Ti(OH)3) co-precipitation. Solid environmental samples were digested with nitric acid (HNO3) and hydrogen peroxide (H2O2). The alpha thin layer source was prepared using CuS micro-precipitation and 210Po was measured by alpha spectrometry. Lead-210 was left to decay for up to a year and indirectly measured via its progeny, 210Po. The chemical recoveries for 210Po and 210Pb were high, 90% and 97%, respectively, for a large variety of samples and a very low minimum detectable activity (MDA) was obtained. The method was validated using standardized solutions and certified reference materials.

Novel Method for Preparing Amorphous Titanyl Sulfate from Hydrous Titanium Oxide

Novel Method for Preparing Amorphous Titanyl Sulfate from Hydrous Titanium Oxide

Micro-CT in the mechanical properties and energy absorption of closed-cell aluminium foam

In situ loading experiments of closed-cell aluminium foam with densities of 0.217 g/cm3, 0.347 g/cm3, 0.414 g/cm3 and 0.588 g/cm3 prepared from industrial pure aluminium 1060 and titanium hydroxide TiH2 foaming agent were carried out by micro-CT. The pore structure parameters such as porosity, pore size distribution and sphericity of aluminium foams with different densities were analyzed, and the effects of pore structure parameters on mechanical properties and energy absorption were investigated to reveal the differences in mechanical characterization of aluminium foams with different densities. The results show that: the collapse of aluminium foam pores in the in-situ loading experiments starts from the high porosity region; aluminium foam with high density has low porosity, small pores and good sphericity; the stress-strain curve of aluminium foam with high density is located above and the elastic modulus is large; the energy absorption capacity is related to the density of aluminium foam, and the energy absorption capacity is large with high density, but the energy absorption efficiency is mainly related to whether the structure is uniform or not.

TITANOMAGNETITE CONCENTRATE PROCESSING BY SORPTION CONVERSION

A hydrometallurgical technology for processing titanomagnetite concentrate has been proposed and justified. It includes the decomposition of the concentrate in low-concentration sulfur-acidic solution in the presence of sulfonic cation exchanger in H+ form with the transfer of the main part of the metals of the titanomagnetite concentrate into the sorbent and obtaining a residue enriched with ilmenite, desorption of metals from the saturated sulfonic cation exchanger with a 5 M sodium chloride solution, fractional hydrolytic precipitation and separation of titanium hydroxide, vanadium-enriched iron hydroxide, pure hydroxide iron and mixtures of iron and manganese hydroxides, regeneration of sulfonic cation exchange resin. The optimal parameters for carrying out individual processes have been determined. The technology practically does not consume sulfuric acid and does not generate liquid waste.

Synergistic effect of amorphous ZnO/crystalline N-TiO2 interface for photoreduction of high concentration Cr(VI)

Although the synthesis of amorphous/crystalline heterojunction is still difficult due to thermodynamic instability, the introduction of amorphous components not only avoids lattice mismatch but also triggers higher photoelectric activity at the interface, making it particularly attractive. Herein, a novel amorphous ZnO/crystalline N-TiO2 heterojunction (aZn/NT) was firstly synthesized by a simple one-pot synthesis process. Non-specific preparation conditions and inexpensive raw materials [e.g., zinc acetate, bis(ammonium lactate) titanium hydroxide (TALH) and citric acid] are significant indicators of this method. The systematic test shows that the hydrolysis of TALH is independent and precedes the substitution reaction of citric acid to form a composite spherical structure. Different testing methods have shown that the newly formed bonds (Ti-O-N-Zn or Ti-N-O-Zn) between the two components during the hydrothermal process are the basis of the heterostructure association. Moreover, the combination of positively charged surfaces, abundant oxygen vacancy defects, and transport channels accelerates the photoreduction of Cr(VI) on aZn/NT surface. The high catalytic rate [0.022 min−1 for 200 mg L−1 Cr(VI)] and low activity loss rate (∼2.3% within 5 cycles) under optimal conditions indicate that the synthesis of highly active heterogeneous materials can be achieved through a simple path.

Layered hydrated-titanium-oxide-laden reduced graphene oxide composite as a high-performance negative electrode for selective extraction of Li via membrane capacitive deionization

In this work, we initially prepared layered lithium titanate (Li2TiO3) using a solid-state reaction. Then Li+ of Li2TiO3 were acid-eluded with Hydrochloric acid to obtain hydrated titanium oxide (H2TiO3). Different weight percentages (50%, 60%, 70%, 80%, and 90%) of the as-prepared H2TiO3 were deposited on a conductive reduced graphene oxide (rGO) matrix to obtain a series of rGO/ H2TiO3 composites. Of the prepared composites, rGO/H2TiO3-60% showed excellent current density, high specific capacitance, and rapid ion diffusion. An asymmetric MCDI (membrane capacitive deionization) cell fabricated with activated carbon as the anode and rGO/H2TiO3-60% as the cathode displayed outstanding Li+ electrosorption capacity (13.67 mg g−1) with a mean removal rate of 0.40 mg g−1 min−1 in a 10 mM LiCl aqueous solution at 1.8 V. More importantly, the rGO/H2TiO3-60% composite electrode exhibited exceptional Li+ selectivity, superior cyclic stability up to 100,000 s, and a Li+ sorption capacity retention of 96.32% after 50 adsorption/desorption cycles. The excellent Li+ extraction obtained by MCDI using the rGO/H2TiO3-60% negative electrode was putatively attributed to: (i) ion exchange between Li+ and H+ of H2TiO3; (ii) the presence of narrow lattice spaces in H2TiO3 suitable for selective Li+ capture; (iii) capture of Li+ by isolated and hydrogen-bonded hydroxyl groups of H2TiO3; and (iv) enhanced interfacial contact and transfer of large numbers of Li+ ions from the electrolyte to H2TiO3 achieved by compositing H2TiO3 with a highly conductive rGO matrix.

EFFECT OF MODIFYING ADDITIVES ON THE PHASE TRANSITION OF ANATASE TO RUTILE

The results of studies on changes in the chemical composition and structure of doped titanium hydroxide during thermal treatment are analysed. It is shown that anatase is formed at first under heating in all cases, and with further increase in temperature or in the duration of thermal treatment it is transformed into rutile. The temperature of the start of anatase-rutile transition depends on the type of doping component. The transition proceeds not abruptly at a certain temperature but gradually over a wide temperature range, while both compounds can exist simultaneously. At a constant temperature, the proportion of rutile increases with an increase in the duration of thermal treatment. It is concluded on the basis of the conducted studies that the samples of titanium dioxide in the presence of doping components represent the broad classes of non-stoichiometric compounds with different crystal structures, and the transition of anatase to rutile is not a polymorphic transformation of the 1st kind but it is a consequence of various chemical processes involving the release of anionic and/or cationic impurities into the gas or solid phases.

TiO2- geopolymer based novel corrosion protective micro-coatings to emaciate mild steel oxidation in severe environments

Now-a-days, cementitious geopolymer coatings are one of the most studied and adaptable coating systems to combat corrosion on low-carbon steel/structural steel. Due to its green and sustainable nature, it has enormous potential to partially replace traditional organic coatings in terms of corrosion resistant properties and economic aspects. Herein, corrosion protection and antibacterial efficiency of titanium oxide (micro-sized, 5/10/15%) containing sodium aluminosilicate (N-A-S-H) geopolymer coating for mild steel is reported to enhance the lifetime of structural steel. Developed coatings were characterized using XRD, FTIR and FESEM. Characterization results indicated the presence of titanium containing new inorganic phase (Sodium titanium oxide hydrate) along with sodium aluminium hydrate phases in XRD, supported by Ti-O stretching vibrations in FTIR along with Si-O-Al stretching vibrations. Microstructural studies using FESEM indicated the uniform distribution of TiO2 in NA-S-H gel matrix. Results revealed that developed coatings depicted corrosion protective characteristics and exhibited adhesion strength between 16.14 and 17.3 MPa. The scratch resistance test revealed that the coating could bear a point load of greater than 5 kg. Minimum percentage weight change and adhesion loss were observed for coating after immersion in NaCl/H2O for 119 days. An accelerated corrosion test (ASTM B117) was performed in the salt environment for 500 h and the best corrosion protective performance was observed for coating formulation containing 10 % TiO2 with maximum rust grading 5. Electrochemical studies showed better corrosion resistance performance for coating formulation containing 10 % TiO2 as compared to the other two formulations containing 5 and 15% TiO2. The antibacterial efficiency of coatings was evaluated by colony count assay (viability method) against the most commonly found gram-positive bacteria Staphylococcus aureus and one gram-negative bacteria Escherichia coli. All three TiO2-incorporated geopolymer coating formulations revealed a good bacterial reduction in percentage with the best performance observed for coating formulation containing 15% TiO2. The accelerated weathering test (ASTM G154-500 h) was performed to ensure the durability and stability of the developed formation. This study developed a novel, environment-friendly, and lucrative cementitious coating material which is potentially suitable for preventing early oxidation and bacterial fouling of mild steel structures.

Photodynamic Treatment of Titanium Dioxide Nanoparticles is a Convenient Method of Adenoviral Inactivation

Today, the search for safe ways to inactivate pathogens is becoming especially relevant in connection with the coronavirus pandemic. Standard methods using chlorides and ultraviolet irradiation have disadvantages related to toxicity and low efficiency. Photodynamic inactivation involving nanoparticles is already used to disinfect water and air from microorganisms and enveloped viruses such as human herpes simplex virus, vesicular stomatitis virus, human immunodeficiency virus, and hepatitis B and C viruses. The aim of this work was to evaluate the possibility of the inactivation of human adenovirus type 5 in an organic medium using titanium dioxide irradiated with ultraviolet light. Methods. The nanosized titanium dioxide material was obtained by the thermal decomposition of a suspension of hydrated titanium dioxide TiO(OH)2 (metatitanic acid). The analysis of the morphology of the TiO2 nanopowder was carried out using electron scanning microscopy (SEM), which showed that TiO2 nanopowder contains soft aggregates of nanoparticles mostly 20‒30 nm in size. Cytotoxicity, virulicidal and antiviral action of titanium dioxide were determined by standard methods using (3-(4,5-dimathylthiazol-2-yl)-2,5-dipheniltetrazolium bromide (MTT). The titanium dioxide suspension was irradiated at a distance of 20 cm from 1 to 30 min with a bactericidal UV lamp (OBB15P, BactoSfera, Poland (254 nm)). The concentration of nanoparticles for irradiation was 1.0 mg/mL. Adenovirus suspension with titer 6.0 log10 TCID50 /mL was added to the nanoparticles immediately after irradiation. The titer of virus synthesized in the presence of titanium dioxide was determined by the end of the virus dilution, which causes 50% of the cytopathic effect of the virus on cells. All studies were performed in three replicates; the number of parallel determinations was three. Results. A dose-dependent effect of titanium dioxide nanoparticles on the viability of Hep-2 cells was revealed. At the NPs concentration of 1 mg/mL, quite a low cell viability was observed (32—39%), with a decrease in concentration to 0.1 and 0.01 mg/mL, the NPs were less toxic (cell viability was in the range of 62—90%). The TiO2 NPs dissolved in glycerin-water had no virulicidal effect, as the virus titer was similar to the control values. Instead, NPs dissolved in propanediol-ethanol reduced the infectious titer of the virus by 6.0 log10, which indicates their high virulicidal effect. The absence of an antiviral effect was shown when NPs were added to infected cells. A decrease in the virus titer by 4.5‒5.0 log10 was recorded uponitsinteracting with irradiated NPs for 1‒30 min. The effect persisted for 3 h after exposure to NPs. Conclusions. The cytotoxic, virulicidal, and antiviral effects of optically active TiO2 nanoparticles were determined in optimal conditions. Regardless of the solvent, NPs had low toxicity at a concentration of 0.1 mg/mL. The TiO2 NPs dissolved in glycerin-water had no virulicidal effect; but dissolved in propanediol-ethanol reduced the infectious titer of the virus by 6.0 log10, which indicates its high virulicidal effect. NPs in a propanediol-ethanol solution, irradiated with UV for 1‒30 min, completely inhibited adenovirus reproduction. NPs in a glycine-water solution reduced the virus titer by 0.5 log10. The control with NPs without irradiation slightly reduced the virus titer (by 0.45 log10). The ability of NPs to completely inactivate adenovirus was maintained for 3 h. It was shown for the first time that the non-enveloped HAdV5 virus could be efficiently inactivated by UV-induced TiO2 photocatalysis.

Formation and growth of anatase TiO2 nanocrystals under hydrothermal conditions

This work is devoted to the study of the processes of formation and growth of TiO2 nanoparticles under hydrothermal conditions. TiO2 nanocrystals were obtained during the dehydration of hydrated titanium dioxide by varying the temperature and duration of hydrothermal treatment, as well as the method of precipitation of the synthesis precursor. The study of various characteristics of the synthesized TiO2 nanoparticles by PXRD, SEM, TEM, and low-temperature nitrogen sorption made it possible to propose mechanisms for the formation of crystalline titanium dioxide from an X-ray amorphous precursor and the growth of titanium dioxide nanocrystals with an anatase structure under hydrothermal conditions. Within the scope of the chosen model of oriented attachment, the dependence of the sizes of TiO2 crystallites on the parameters of hydrothermal synthesis is mathematically described. It was concluded that the direct precipitation of the synthesis precursor from titanium tetrachloride is superior to the reverse. It is shown that the temperature of hydrothermal treatment largely determines the size and morphology of the formed crystallites and TiO2 nanoparticles, the rate of the crystallization process, and the preferred mechanisms of nanocrystal growth, while the duration of synthesis affects the agglomeration processes and the specific surface area of titanium dioxide powders.

Preparation of porous titania particles via hot water or hydrothermal treatment of porous hydrous titania and their photocatalytic ability

Preparation of porous titania particles via hot water or hydrothermal treatment of porous hydrous titania and their photocatalytic ability

Use of nano titanium hydroxide and nano zirconium hydroxide fixed filter paper for rapid detection of Staphylococcus aureus in dairy products by PCR without pre-enrichment

Use of nano titanium hydroxide and nano zirconium hydroxide fixed filter paper for rapid detection of Staphylococcus aureus in dairy products by PCR without pre-enrichment

Galvanic corrosion mechanism of Ti-Al coupling: the impact of passive films on the coupling effect

The light metals of titanium and aluminum are often used together, so the risk of galvanic corrosion is inevitable. However, the passive films on both metals will change during the galvanic corrosion process, which affects the coupling effect. Thus, this work aims to investigate the variation of passive films with increasing galvanic corrosion time, and further clarify their impact on galvanic corrosion rate. Motto-Schottky (M-S) curves, electrochemical impedance spectroscope (EIS), zero charge potential and XPS were used to characterize the state of the passive films, potentiodynamic polarization and zero resistance ammeter (ZRA) were utilized to analyze the cathodic and anodic reactions on Ti-Al coupling. The results indicate that during galvanic corrosion process the passive film on cathode titanium alloy is transformed from titanium dioxide to low-valent titanium oxide and titanium hydroxide due to hydrogen adsorption behavior, resulting in the increase of defect density in passive film. The passive film on anode aluminum alloy degrades rapidly in the initial galvanic corrosion stage due to the action of Cl− accumulation by non-electrostatic action, also the cathodic reaction on anode aluminum alloy is relatively high under coupled condition, which plays an important role in the high corrosion rate of anode aluminum alloy.

Evaluating high temperature photoelectrocatalysis of TiO2 model photoanode

Sunlight concentration has been demonstrated as one promising strategy for practically photoelectrochemical (PEC) water splitting with exceeding 10% solar-to-hydrogen efficiency. However, the operating temperature of PEC devices, including the electrolyte and photoelectrodes, can be elevated to 65 ℃ naturally due to the concentrated sunlight and the thermal effect of near-infrared light. In this work, high temperature photoelectrocatalysis is evaluated using titanium dioxide (TiO2) photoanode as a model system, which is believed to be one of the most stable semiconductors. During the studied temperature range of 25–65 ℃, a linear increment of photocurrent density with a positive coefficient of 5.02 μA cm−2 K−1 can be observed. The onset potential for water electrolysis shows a significant negative shift by 200 mV. An amorphous titanium hydroxide layer and a number of oxygen vacancies generate on the surface of TiO2 nanorods, promoting the water oxidation kinetics. During long-term stability testing, the NaOH electrolyte degradation and TiO2 photocorrosion at high temperatures could cause the decaying photocurrent. This work evaluates the high temperature photoelectrocatalysis of TiO2 photoanode and reveals the mechanism of temperature effects on TiO2 model photoanode.

STUDY ON PHOTOCATALYTIC PERFORMANCE OF TiO2 FILM PREPARED ON Q235A STEEL AND ITS DEGRADATION OF ORGANIC POLLUTANT IN SIMULATED WASTEWATER

TiO2 film is prepared on the surface of Q235A substrate from an acid solution ([Formula: see text]) to research its degradation of methylene blue organic pollutant in wastewater. The titanium oxysulfate is used as the titanium precursor to provide the source of titanium. The preparation of TiO2 film is mainly a polymerization reaction of titanium oxysulfate, which makes Ti2O[Formula: see text] and OH− combine to produce [Ti2O5(OH)2]n precipitation deposited on the cathode surface by electrochemical reaction. TiO2 film is formed after high temperature heating. The nitrate ion which derives from potassium nitrate in the electrolyte is reduced to hydroxide ion during the electrochemical reaction process, resulting in the formation of titanium compounds and titanium hydroxide. The TiO2 film prepared from solution containing 0.2[Formula: see text]mol/L KNO3 has the best photocatalytic performance which can effectively degrade the methylene blue organic pollutant in wastewater. However, when the KNO3 in the solution is 0.25[Formula: see text]mol/L, excessive hydroxide ions inhibit the hydrolysis of titanium salts and accelerate the oxygen evolution resulting in the decrease of degradation efficiency.