Titanium Butoxide Research Articles

Improving Photocatalytic Efficiency with Titanium Dioxide Quantum Dots

Titanium dioxide quantum dots (TiO2-QDs), synthesized using a microwave-assisted method, represent a significant advancement in photocatalysis, particularly in the treatment of environmental pollutants. This study focuses on TiO2-QDs synthesized at 200°C for a duration of 5 minutes, using titanium butoxide as a precursor. Characterization through TEM, XRD, PL, and UV-Vis-DRS analyses revealed uniform quantum dots with an average size of 5.28 nm, a bandgap energy of 3.22 eV, and a crystalline anatase phase, indicative of high photocatalytic activity. Notably, these TiO2-QDs demonstrated exceptional performance in degrading methylene blue (MB) in water, achieving a remarkable treatment efficiency of 97.6% in 120 min, significantly outperforming both conventional titanium dioxide nanoparticles and commercial titanium dioxide materials. The reaction conditions were evaluated based on factors such as catalyst dose, initial MB concentration, and pH. The results indicate that optimal degradation efficiency of MB was achieved at a pH of 7, with a catalyst dose of 0.15 g/L and at a low MB concentration. The efficiency slightly decreased to 94.5% after five reuse cycles, emphasizing its significant reusability and stability. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Synthesis and design strategies of codoped titanium dioxide with band alignment and multiple reflections of incident light for efficient visible light activity

To increase the visible-light photocatalytic performance of Titania, it was codoped with specific elements and was effectively synthesized. The goal of enhancing visible-light photocatalytic performance was achieved by broadening its absorption spectrum in the visible light range and enhancing the quantum efficiency of the photocatalytic reaction toward the degradation of the hazardous dye methyl orange. Mixed phase photocatalyst with different percentage hierarchical secondary nanostructure has been synthesized by the combination of chemical bath deposition methods and hydrothermal. The density of the sprout-like branches changes from the concentration levels of titanium butoxide in the precursor solution. Based on the experimental analysis, a mechanism was proposed to interpret the evolution of the secondary growth. The band edge difference between anatase and TiO2(B) phases induces transfer of charge at the interface. The result revealed that in the TiO2 crystal some O-sites were substituted by N and S anions resulting in band mixing and incorporation of extra energy states in between the valence band maxima and conduction band minimum, which caused a shift towards longer wavelengths in the absorption edge. Compared with pure TiO2 nanobelt, the surface modified doped samples exhibited good visible light activity. The combined effect of fast charge transfer in the atomic level contact between two phases and localized N 2p and S 3p band above valence-band edge in the same material makes titanium dioxide suitable for use in the presence of visible light.

In Situ Driven Formation of Anatase/Brookite/Rutile Heterojunction N/TiO2 Nanocrystals as Sustainable Visible-Light Catalysts.

Visible-light active anatase/brookite/rutile (A/B/R) ternary N-doped titania (N/TiO2) crystals are successfully prepared by a facile sol-gel method using titanium butoxide and benign N-dopant source, guanidinium chloride. Systematically varying the aging time (1, 4, 8, and 12 d), its influence on physicochemical properties of as-obtained spherical heterojunction nanomaterials is studied. Detailed characterizations confirm that a substantial amount of anatase (88% to 50%) is transformed to rutile (2% to 38%) via intermediate brookite phase (9% to 25%) as the function of aging time; not only the A/B/R phase content of the samples is tuned by sol-gel aging time of the precursors solution but also their optical-response and methylene blue photocatalytic properties are profoundly dictated. Notably under visible-light irradiation, the photostable rutile rich mesoporous A/B/R triphasic N/TiO2 (50% A, 12% B, 38% R) aged for 12 d demonstrates higher degradation activity (97%) with a faster degradation rate (0.033 min-1) than both lesser aged N/TiO2 and undoped titania. This enhancement is attributed to the synergistic effect of interstitial-N-doping and optimal A/B/R interfacial charge transfer that leads to higher light absorption, lower bandgap energy and well-separated charge carriers. The current work provides a new perspective for designing highly active visible-light heterostructure nanomaterials with controllable phase composition.

Acidic phosphonium-based ionic liquid encapsulated on titania particles with enhanced electrorheological response

Research on electrorheological (ER) fluids has led to significant advancements in the development of smart materials that adjust their viscosity in response to applied electric fields. This study focused on synthesizing titania ionogel-based particles (TiO2-IL) using an environmentally friendly sol-gel process involving tetrabutoxy-titanium (TBT) combined with an ionic liquid (IL), specifically 11-carboxyundecyl-triphenyl-phosphonium bromide. The successful incorporation of the IL into the TiO2 particles was confirmed through thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and zeta potential analysis. The electrorheologial properties of TiO2-IL ionogel suspension in silicone oil were compared with those of pure TiO2 suspension. The addition of the ionic liquid (IL) significantly enhanced the electrorheological (ER) properties of the fluid, achieving a shear stress of approximately 1340Pa at an electric field strength of 5kV/mm. The fluid also exhibited excellent reversibility and a rapid response to changes in the electric field, which is attributed to the higher polarizability by the IL. Furthermore, the study observed low current density during operation, which helps maintain the fluid’s integrity and longevity under high electric fields. The fluids demonstrated stable ER effect across a temperature range of 40 to 70 ℃ and a reasonable sedimentation stability of around 80%. These characteristics, combined with the moderate conditions for particle preparation, make the TiO2-IL fluid a promising candidate for ER applications.

Titanium (IV) μ-Oxo Complex Supported by Phenoxyimine Ligand: Synthesis, Crystal Structure Characterisation, DFT and Molecular Docking Studies

Background: Most of the transition elements in the 3d series (first row transition metals) have been discovered to be extremely significant and practical in biological systems. Naturally, many of the enzymes that are present in the human body system act as catalysts for biological processes and are made of coordination compounds or complexes. Objective: The complex has been characterised by various spectroscopic and analytic techniques. A suitable crystal analysed by X-ray diffraction establishes the formation of a stable binuclear µ-oxo-complex with a hexacoordinate titanium centre. Methods: A new crystalline complex [Ti{La}] has been synthesised in the reaction of titanium butoxide with a phenoxyimine ligand in a 1:1 stoichiometry in toluene at room temperature under a nitrogen atmosphere. The newly synthesised Ti complex has undergone density functional theory and docking study. Results: The crystal shows a monoclinic system with space group C 1 2/c 1. X-ray crystal structure analysis reveals that this complex has a rhomboidal Ti-O-Ti core and exhibits a C2 symmetric conformation with distorted octahedral geometry. Density Functional Theory (DFT) calculations giving insights into the frontier orbitals and mulliken charge analysis, which showed good correlation with the experimental findings. Additionally, in silico molecular docking of ligand and complex was carried out against the HER2 inhibitor kinase. Conclusion: This complex exhibits a higher binding energy of ΔGb = -19.7 kcal/mol with the active pocket of HER2 (PDB:7JXH) than the ligand ΔGb = -8.5 kcal/mol.

TiO2-ZnPc nanoparticles functionalized with folic acid as a target photosensitizer for photodynamic therapy against glioblastoma cells

The use of TiO2 as a photosensitizer in photodynamic therapy is limited due to TiO2 generates reactive oxygen species only under UV irradiation. The TiO2 surface has been modified with different functional groups to achieve activation at longer wavelengths (visible light). This work reports the synthesis, characterization, and biological toxicity assay of TiO2 nanoparticles functionalized with folic acid and combined with a zinc phthalocyanine to obtain a nano-photosensitizer for its application in photodynamic therapy for glioblastoma cancer treatment. The nano-photosensitizer was prepared using the sol-gel method. Folic acid and zinc phthalocyanine were added during the hydrolysis and condensation of titanium butoxide, which was the TiO2 precursor. The samples obtained were characterized by several microscopy and spectroscopy techniques. An in vitro toxicity test was performed using the MTT assay and the C6 cellular line. The results of the characterization showed that the structure of the nanoparticles corresponds mainly to the anatase phase. Successful functionalization with folic acid and an excellent combination with phthalocyanine was also achieved. Both folic acid-functionalized TiO2 and phthalocyanine-functionalized TiO2 had no cytotoxic effect on C6 cells (even at high concentrations) in comparison to Cis-Pt, which was very toxic to C6 cells. The materials behaved similarly to the control (untreated cells). The cell viability and light microscopy images suggest that both materials could be considered biocompatible and mildly phototoxic in these cells when activated by light.Graphical

The room temperature signature of micro to nanocrystalline calcium copper titanate (CCTO) thin film by a modified sol-gel technique and tailoring its material property

This study aims to identify an alternative route for the low-temperature synthesis of calcium copper titanate (CCTO) thin films and to explore a new understanding of precursor composition strategy and its relationship to thin-film combustion synthesis using a modified sol-gel technique. Micro-sized to nano-sized CCTO thin films were effectively deposited onto various substrates using a rapid and modified sol-gel process at remarkably low temperatures (∼100 °C), with room temperature phase formation of CCTO observed via FTIR and Raman spectroscopy. Calcium nitrate, copper nitrate, and titanium (IV) butoxide served as precursor materials to create the sol for spin coating. The resulting CCTO thin films were polycrystalline, uniform, and compact. The surface morphology and optical properties of these films were analyzed using Atomic Force Microscopy (AFM), Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (FESEM-EDAX), X-Ray Diffraction (XRD), and UV–VIS spectrophotometry. XRD confirmed various phases of CCTO on different substrates, with significant intensity variations in the peaks at different annealing temperatures. The XRD patterns on three different substrates-glass, SnO2 coated glass, and SiO2 coated Si—revealed different CCTO phases such as CCTO (301), CCTO (220), CCTO (400), and CCTO (422). EDAX analysis confirmed the presence of Ca, Cu, Ti, and O. The band gap varied from 2.5 to 3.8 eV depending on the annealing temperature. Capacitive vs. frequency response, dielectric loss, and I-V characteristics of the films were measured using MIM (Metal-Insulator-Metal) or SIM (Semiconductor-Insulator-Metal) structures.

TiO2 nanofilms for surface-enhanced Raman scattering analysis of urea

In this study, titanium dioxide (TiO2) nanofilms with nanoparticle structure were grown in situ on metallic aluminum (Al) sheets using a simple sol-hydrothermal method. Al sheets were chosen because they can form Schottky junctions with TiO2 during the calcination process, thus achieving a tight bonding between the nanoparticles and the solid substrate, which cannot be achieved with conventional glass substrates. The substrates synthesized with different contents of titanium butoxide [Ti(OBu)4] were investigated using 4-mercaptobenzoic acid as a probe molecule, and the results showed that the substrate with 9 % of the total volume of Ti(OBu)4 had the highest surface-enhanced Raman scattering (SERS) performance. As a low-cost SERS substrate that is simple to synthesize, it has excellent signal reproducibility, with a relative standard deviation of 4.51 % for the same substrate and 6.43 % for different batches of synthesized substrates. Meanwhile, the same batch of substrate can be stored at room temperature for at least 20 weeks and still maintain stable SERS signals. In addition, the synthetic substrate was used to quantitatively detect urea with a detection limit of 4.23 × 10−3 mol/L, which is comparable to the application of noble metal substrates. The feasibility of this method was verified in human urine, and the results were consistent with the clinical results, indicating that this method has great potential for clinical application.

Photocatalytic degradation of 2,4-dichlorophenoxyacetic acid by electrospun TiO2 nanofibres synthesised from two different titanium molecular precursors.

The evaluation of the photocatalytic properties of electrospun TiO2 nanofibres (TiO2-NFs) synthesised in the same experimental conditions using two distinct precursors, tetraisopropyl orthotitanate (TTIP) and tetrabutyl orthotitanate (TNBT), with morphology and crystalline structure controlled by annealing at 460°C for 3h is presented. The presence of circular-shaped TiO2-NFs was corroborated by scanning electron microscopy (SEM). By using X-ray photoelectron spectroscopy (XPS), the chemical binding energies and their interactions of the TiO2 with the different incorporated impurities were determined; the most intense photoelectronic transitions of Ti 2p3/2 (458.39eV), O 1s (529.65eV) and C 1s (284.51eV) were detected for TTIP and slightly blue-shifted for TNBT. By using energy-dispersive X-ray spectroscopy (EDS), the chemical element percentages in TiO2 were determined. Using X-ray diffraction, it was found that the annealed electrospun TiO2-NFs presented the anatase crystalline phase and confirmed by Raman scattering. Bandgap energies were determined by diffuse reflectance spectroscopy at room temperature. The photocatalytic degradation of 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide under exposure to ultraviolet light was studied using the TiO2-NFs obtained with the two molecular precursors. The results showed that the catalyst, prepared with the TTIP precursor, turned out to be the one that presented the highest photocatalytic activity with a half-life time (t1/2) of 28min and a degradation percentage of 93%. The total organic carbon (TOC) in the solutions resulting from the 2,4-D degradation by the TiO2-NFs was measured, which showed a TOC removal of 50.67% for the TTIP sample and 36.14% for the TNBT sample. Finally, by using FTIR spectroscopy, the final chemical compounds of the degradation were identified as H2O and CO2.

Silver nanoparticles-promoted bismuth titanate perovskite nanosheets photocatalyst for water purification

Photocatalysis is a recognized approach in the detoxification of pollutants and in water splitting. Such process is more appealing when it is driven by visible or solar light. In this context, we synthesized bismuth titanate perovskite oxide (Bi4Ti3O12, BTO) photocatalyst by sol–gel hydrothermal process. The resulting BTO materials was affected by the titania source and by the synthesis medium pH parameter. Titanium butoxide [Ti(n-BuO)4] was much better than titanium isopropoxide [Ti(i-PrO)4] in producing regular nanosheets with higher surface area, while 75 ml of 5.0 M sodium hydroxide was the optimum concentration for the synthesis of regular, thin, porous, almost equal size nanosheets. The photocatalytic activity of BTO was improved by loading silver nanoparticles (AgNPs) by photo-assisted reduction. The optimum weight percent of loading AgNPs was found to be 1.5 % because it led to the highest light absorbance, the smallest band gap energy, the minimum rate of electron-hole recombination. The photocatalytic degradation efficiency of 1.5 wt% Ag/BTO reached as high as 99.0 % of rhodamine B (RhB, 100 ml, 6 ppm of initial concentration) under 70 min of irradiating visible light (>420 nm). Moreover, pH had a strong influence on the photocatalytic activity of 1.5 wt% Ag/BTO, with pH = 3.0 was the optimum, owing to its impact on the interaction between the positively-charged photocatalyst surface and the negatively-charged RhB molecules. It was found that superoxide radicals played key role in the photocatalytic activity.

Enhanced photocatalytic degradation of toluene on surface C- and CN-modified TiO2 microspheres

Surface modified TiO2 materials are widely used in photocatalytic environmental purification processes. The employment of solution might exert a discernible influence on the catalyst. In this study, we incorporated tetrahydrofuran (THF) and pyrrolidine (PY) during the hydrolysis of titanium butoxide (TBOT) to modify the surface of TiO2, successfully synthesizing surface C-modified TiO2 (THF-TiO2) and surface CN-modified TiO2 (PY-TiO2) catalysts. The assistance of THF and PY not only reduced agglomeration, but also increased the specific surface area of both catalysts, leading to the exposure of more active sites in TiO2 during the photocatalytic degradation of toluene. When compared to the unsatisfactory degradation of toluene (80%) and CO2 mineralization efficiencies (40–45 %) observed using unmodified TiO2, the synthesized THF-50-TiO2 and PY-1-TiO2 microspheres demonstrated enhanced toluene degradation efficiency to 100 % and 99.8 %, respectively, and improved mineralization efficiencies to 76 % and 80 % after 120 min of ultraviolet irradiation. The experimental data and characterization results indicate that the surface-modified carbon species in THF-50-TiO2 facilitate the acceleration of electron-hole pair separation and suppress recombination. In contrast, partial nitrogen species introduced into the surface lattice of PY-1-TiO2 narrow its band gap and induce a visible light response. Overall, this study provides two methods to modify the surface of TiO2, which can be applied to prepare outstanding photocatalysts for possible application in the degradation of volatile organic compounds (VOCs) present in the air. Furthermore, it has been confirmed that solution have a significant impact on the catalyst.

Self-assembly TiO2@Silane@SiO2 core-shell as s-scheme heterojunction photocatalyst against methylene blue degradation: synthesis and mechanism insights

Pollutants are the most critical threats to the health of water resources. On this basis, fabricating a core-shell as an S-scheme heterojunction photocatalyst for the treatment of wastewater from methylene blue (MB) dye was aimed in this research. In this study, TiO2-doped silanized silica dielectric nanocomposites were synthesized as self-assembly TiO2@Silane@SiO2 heterojunction through sol-gel and solvothermal methods using tetrabutyl orthotitanate (TBOT) as precursor followed by calcination at 650 °C for 3 h. Silanization of silica nanoparticles was done at two different concentrations. The results showed that layer-by-layer synthesis (i.e. self-assembly of APTES on SiO2, precipitation of TiO2 layer on it by sol-gel technique and then calcination) was the optimum preparation method. The structural and morphological features were investigated by XRD, FTIR, BET, TGA-DTG, FE-SEM, EIS and ESR techniques. It was found that the band gap energy of nanocomposite particles reduced from 3.14 eV for the sample prepared by the solvothermal method (i.e. without APTES) to 2.91 eV (i.e. shifting the light absorption from UV to the visible region) for the sample prepared by the sol-gel layer-by-layer method. The prepared samples were used against the photo-degradation of MB. TiO2@Silane@SiO2 core-shell nanoparticles exhibited efficient photocatalytic degradation against MB with a photodegradation efficiency of 85 % under UV and 60 % under visible irradiation. Finally, the prepared nanocomposite particles were incorporated to an emulsion acrylic resin to prepare photocatalytic polymer film. The prepared films were evaluated for photocatalytic degradation of MB stain and mechanical performances. It was found that the TiO2@Silane@SiO2 nanocomposite particles that prepared by layer-by-layer method caused about 56 % improvement in hydrophobicity, 276.7 % increment in the tensile strength, 109.6 times enhancement in the modulus, 381.4 times enhancement in the toughness and 57.6 times improvement in the elongation at break of the acrylic film compared to the pure TiO2-containing acrylic film, respectively.

Effect of titanium alkoxide on structure, morphology, and biocompatible properties of sol-gel synthesized TiO2 films

The purpose of this work was to study the influence of the nature of titanium alkoxide, used as a precursor for the synthesis of TiO2 films by the sol-gel method, on the crystal structure and morphology of coatings, as well as their biological compatibility. TiO2 coatings were synthesized on silicon substrates using the dip-coating method. Titanium alkoxides with different molecular weights were used as precursors: titanium tetraethoxide, titanium tetraisopropoxide, and titanium tetrabutoxide. The influence of the nature of the titanium precursor on the morphology and thickness of TiO2 films was determined using scanning electron microscopy. The structural properties of the coatings were studied by X-ray diffraction and Raman spectroscopy. Cell viability assay was performed on TiO2/Cu-Si(111) structures to evaluate the ability of TiO2 coatings synthesized from different precursors to prevent the release of toxic ions from the substrate. The biological compatibility of TiO2 films with various surface morphologies and structures was assessed based on the chorioallantoic membrane assay. It has been demonstrated that the type of titanium alkoxide utilized has a substantial influence on the morphology and crystal structure of TiO2 films produced through the sol-gel method. Furthermore, the structural properties of the coatings consequently impact their biological compatibility. Coatings synthesized from titanium tetrabutoxide exhibited the highest protective properties and biological compatibility.

TiO<sub>2</sub>- Polyurethane Cocopol Blend Nanocomposites as an Anticorrosion Coating for Mild Steel

Mild steels were the most frequently used materials in industries and factories since it possesses unique properties but due to weak environmental changes, these cause deterioration and corrosion to the materials’ surface. To prevent such, protective coatings were applied to protect against corrosion in which by incorporating titanium nanoparticles in polyurethane coatings. Titanium nanoparticles were synthesized using titanium butoxide as a precursor. The obtained nanoparticles were used as an inhibitor mixed with coconut oil-based polyurethane polyol blend against the corrosion on mild steel of 3.5% of sodium chloride solution which has been investigated using the Tafel polarization technique. The polarization curves of the corrosion potential for bare mild steel, along with different amounts of titanium nanoparticles coating, exhibit a positive shift. This shift indicates that the coating film effectively reduces the transport path for the corrosive solution, providing a protective barrier against corrosion. This observation is further supported by the results of the adhesive strength test, which demonstrates that the attachment of the coating films to the metal increases with higher amounts of titanium nanoparticles. This indicates improved adhesion and a stronger bond between the coating and the substrate, enhancing the overall corrosion resistance. The increase of contact angle test confirms the improvement of the coating’s hydrophobicity with the addition of titanium nanoparticles. This suggests that the coating repels water more effectively, further contributing to its protective properties against corrosion. Results also show that the addition of 4wt% of titanium nanoparticles has better anti-corrosion properties than the PU CCP alone, and 0.5, 1.0, and 2.0wt% of titanium added.

TiO2-Mesoporous Ceria Carrier Modified with Sodium Benzoate: An Innovative Polyurethane Matrix for Enhanced Corrosion Protection of steel

An advanced corrosion protection system, distinguished by multilevel corrosion inhibition, was developed by integrating modified hybrid carriers strategically reinforced within a polyurethane (PU) matrix. For this purpose, mesoporous ceria (mCeO2) was synthesized via a hydrothermal hydrolysis process and incorporated with titanium butoxide to synthesize a hybrid core-shell titania mesoporous ceria (TiO2/mCeO2) carrier system. The TiO2/mCeO2 carrier system was modified with sodium benzoate (SB used as a corrosion inhibitor) to develop a modified TiO2/mCeO2-SB system. The synthesized modified particles were then reinforced into the polyurethane-based matrix to study the corrosion inhibition performance. Benefitting the corrosion-inhibiting properties of modified polyurethane-based coatings, the reinforcement of these modified TiO2/mCeO2 particles resulted in a notably improved anti-corrosion performance in the coating after immersion in 3.5 wt. % NaCl solution for four weeks, the impedance was estimated to be 96.65 GΩ.cm2, which is nearly four orders of magnitude than that of blank PU coatings. This is attributed to the synergistic anti-corrosion performance of TiO2 and SB. The protective layer formed due to the interaction of titania and hydroxyl ions resulted in the formation of Ti(OH)4 and SB absorbed on the steel surface, making iron unavailable for further electrochemical reaction. This work reports on the strategy to build a corrosion inhibition coating system, which introduces a new perspective for extending the lifespan of metals.

Size controlled synthesis of hydrous TiO2 spheres by a thiol structure directing agent and its application in photocatalysis and efficient DSSC cells

In this work, hydrated TiO2 spheres (HTS) of the submicron order have been developed. Normally, the group of amines, such as dodecylamine, hexadecylamine, methylamine, and NH3, had been the main structure-directing agents (SDAs) used in the sol–gel process to obtain monodisperse hydrated TiO2 spheres. Even though progress has been made in the synthesis of HTS, it is crucial to include new SDAs capable of synthesizing monodisperse HTS with improved or new properties for practical applications. In this work, for the first time we demonstrate that a thiol, 3-mercaptopropionic acid (MPA), can be used as an effective SDA to synthesize monodisperse hydrous TiO2 spheres with a controllable particle diameter between 150 to 950 nm. Experimental preparation parameters such as Ti concentration, [MPA]/[Ti] and [Water]/[Ti] molar ratio in the precursor solution (Titanium (IV) butoxide—MPA—ethanol—water) were thoroughly optimized to get both high yield and high monodispersity. Remarkably, a wide range in the [Water]/[Ti] molar ratio, 17 to 118, was achieved, which is much wider than the typical Rw range of the amines group of 2 to 16, thus giving more control for choosing the HTS final size. The controlled growth of hydrated TiO2 nanospheres was explained according to the LaMer and DVLO theory. To demonstrate the applicability of the HTS synthesized using MPA as SDA, the development of efficient dye-sensitized solar cells getting an energy conversion greater than 9% as well as of an effective photocatalytic degradation process of the analgesic acetaminophen under concentrated solar radiation was conducted.

Precursor-concentration-controlled Morphology of TiO2 Nanorod/Nanoflower Films for Enhanced Photoelectrochemical Water Splitting and Investigating Their Growth Mechanism

Titanium dioxide (TiO2) has been considered as one of the most promising photocatalysts for photoelectrochemical (PEC) water splitting. Therefore, numerous efforts have been devoted to improving its PEC water splitting performance. In this study, TiO2 nanorod/nanoflower (NRF) films with controlled morphology were synthesized on fluorine-doped tin oxide (FTO) glass substrates by following a facile one-step hydrothermal method. The TiO2 NRF films were characterized by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), energy-dispersive X-ray spectrometer (EDS), and ultraviolet-visible (UV-Vis) spectrophotometer. FE-SEM showed that the TiO2 films are composed of a simultaneous growth of a primary layer of TiO2 nanorod arrays (NRAs) and a second layer of TiO2 nanoflowers (NFs). The proposed growth mechanism highlighted the influence of precursor concentration on nucleation sites, affecting the preferred crystallographic plane growth of rutile TiO2 and nanorod alignment on the FTO substrate. Intriguingly, TiO2 NRF films prepared with 1.0 mL of titanium butoxide exhibited a maximum photocurrent density of 3.58 mA.cm−2 at 1.23 V versus (vs.) the reversible hydrogen electrode (RHE), along with a maximum photoconversion efficiency of 0.69%. The enhanced photocurrent density and photoconversion efficiency were attributed to the optimum thickness in the range of 4.52-7.31 µm, which caused the film to be formed with a unique morphology of the primary layer with well-vertically aligned nanorods and the second layer of flowers consisting of numerous rods stacked on top of one another. This study demonstrates the importance of designing semiconductors with 1D nanorod/3D nanoflower structures as high-performance photoelectrodes for PEC water splitting. Copyright © 2024 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Study on Crystal Structure, Surface Area, and Energy Gap Behaviors of Nanotitania Polymorphs Prepared Using Monoethanolamine

Polymorphous nanotitania samples were prepared from titanium butoxide (TTB) as a precursor using sol-gel processing in ethanol as a solvent, without and with monoethanolamine (MEA). The experiments used 5.25 mL TTB and MEA with varied volumes of 0.5, 1.0, 1.5, and 2.0 mL. The sample without MEA was specified as sample A, and the samples produced using MEA were specified as samples B, C, D, and E, respectively. All samples were calcined at 500 °C for 4 h and then collected data by X-ray Diffraction (XRD), the Brunauer-Emmett-Teller (BET) method used to analyze Surface Area Analyzer (SAA), Transmission Electron Microscopy (TEM), Raman Spectroscopy, and UV-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS). The results of XRD characterization indicate that samples A and B form anatase phase, while samples C and D are composed of anatase, brookite, and rutile phases, and sample E is consisted of anatase and brookite phases with weight percentages of (94.53 ± 1.72) % and (5.47 ± 0.36) %, respectively. The presence of the three phases of titania is also confirmed by Raman spectroscopy analysis, which showed anatase peaks at 146, 197, 398, and 513 cm-1, brookite peaks at 245 and 402 cm-1, and rutile peaks at 319, 436, and 612 cm-1. According to XRD, the samples have the particle size in the range of 14-19 nm. A representative sample (sample C) was also characterized using TEM, revealing a particle size of 16.0 ± 0.3 nm. This representative sample revealed the largest surface area of 172.2 m2/g, as seen by BET, and the lowest energy gap of 3.03 eV.

Pressure-Induced Defects and Reduced Size Endow TiO2 with High Capacity over 20 000 Cycles and Excellent Fast-Charging Performance in Sodium Ion Batteries.

Anatase TiO2 as sodium-ion-battery anode has attracted increased attention because of its low volume change and good safety. However, low capacity and poor rate performance caused by low electrical conductivity and slow ion diffusion greatly impede its practical applications. Here, a bi-solvent enhanced pressure strategy that induces defects (oxygen vacancies) into TiO2 via N doping and reduces its size by using mutual-solvent ethanol and dopant dimethylformamide as pressure-increased reagent of tetrabutyl orthotitanate tetramer is proposed to fabricate N-doped TiO2/C nanocomposites. The induced defects can increase ion storage sites, improve electrical conductivity, and decrease bandgap and ion diffuse energy barrier of TiO2. The size reduction increases contact interfaces between TiO2 and C and shortens ion diffuse distance, thus increasing extra ion storage sites and boosting ion diffusion rate of TiO2. The N-doped TiO2 possesses highly stable crystal structure with a slightly increase of 0.86% in crystal lattice spacing and 3.2% in particle size after fully sodiation. Consequently, as a sodium-ion battery anode, the nanocomposite delivers high capacity and superior rate capability along with ultralong cycling life. This work proposes a novel pressure-induced synthesis strategy that provides unique guidance for designing TiO2-based anode materials with high capacity and excellent fast-charging capability.

Synthesis of hydrophobic biopolyesters from depolymerized Pinus radiata bark suberin

Abstract The bark of Pinus radiata offers an underutilized source of high-value renewable chemicals such as extractable polyphenols and lipophilic compounds (waxes and suberin). Here, the depolymerization and extraction of suberin from P. radiata bark and its repolymerization to form novel polyesters are reported. Three different strategies were evaluated for repolymerization of the suberin monomers, with starting materials and products characterized using chemical and thermal analysis techniques. The inclusion of comonomer (1,12-dodecanediol) to provide stoichiometric balance improved the conversion, product yield, solubility and increased molecular weight. Enzymatic polymerization conditions gave the highest yield, while the highest molecular weight was achieved using titanium butoxide, demonstrating that polymerization conditions could be varied to target desired product properties. Products were hydrophobic, as shown by contact angles, ϴ ≥ 90° after 30 s. This work highlights opportunities for utilizing suberin to add value to a P. radiata bark biorefinery concept. Potential future applications include its use as a starting material for novel bio-based polymers that can serve as water-repellent surfaces and coatings, replacing established products derived from fossil resources.