Tetrabutyl Titanate Research Articles

Preparation and research of Mn-TiO2/ Fe membrane with high efficiency light-oil/water emulsion separation

To control the water pollution caused by industrial oily wastewater, scientific research in the field of oil-water separation has begun all over the world, which has also attracted extensive attention to green advanced separation materials. Herein, we used stainless steel mesh as one of the reactants to load metal oxide particles formed by tetrabutyl titanate (TBT), and manganese acetate on cotton mesh under acidic conditions to prepare a membrane material with excellent oil-water separation. The results showed that the 0.1/0.3/0.5 Mn-TiO2/Fe membranes prepared by high-temperature hydrothermal reaction had an excellent separation effect in the light oil and water separation after 10 cycles, and its maximum oil-water separation efficiency was 89.87%, 92.65% and 96.96% respectively. At the same time, the membrane still had good hydrophobicity after acid, alkali and high temperature and low-temperature treatment. In the light oil and water separation experiment measured after 15 times of friction with sandpaper, the 0.5Mn-TiO2/Fe membrane showed good durability, and the average separation efficiency was 93.82% respectively. This diversified wettability and separation process of stainless steel mesh load on the membrane surface has a wide range of potential applications in environmental protection, energy utilization, industrial manufacturing and so on.

Preparation and Photocatalytic Properties of Anatase TiO2 with Hollow Hexagonal Frame Structure

Titanium dioxide (TiO2) has been widely used to solve energy and environmental pollution problems due to its excellent properties. In this study, the precursor (HTiOF3) with a spherical structure composed of hexagonal prisms was prepared via a simple solvothermal method using tetrabutyl titanate, hydrofluoric acid, glacial acetic acid and isopropanol as raw materials. Then, the calcination time and temperature of the precursor were controlled to prepare anatase TiO2 with different morphologies, and the photocatalytic performance of the prepared catalysts was studied. When the precursor was calcined at 600 °C for 7 h, the prepared TiO2 had a unique hexagonal framework structure and exhibited excellent photocatalytic performance. The degradation rate of the RhB solution was 98.58% at 40 min and the rate of hydrogen evolution was 2508.12 μmol g−1 h−1.

Preparing Biomass Carbon Fiber Derived from Waste Rabbit Hair as a Carrier of TiO2 for Photocatalytic Degradation of Methylene Blue.

In the past few years, biomass carbon materials have gained wide attention from many scholars as TiO2 carrier materials to improve photocatalytic activity due to their renewable, green, low-cost, and high-efficiency advantages. In this study, TiO2/carbonized waste rabbit fibers (TiO2/CRFs) nanocomposites with the hierarchical microporous/mesoporous structure were fabricated by a combination of carbonization, immersion, and calcination methods using tetrabutyl titanate as the titanium source and waste rabbit hair as the carbon source. The properties and catalytic activity of TiO2/CRFs composite were evaluated based on several characterization techniques and methylene blue (MB) photodegradation studies. The results showed that the degradation of MB by TiO2/CRFs could reach 98.1% after 80 min of solar irradiation. Moreover, TiO2/CRFs still maintained high photocatalytic activity after five cycles of degradation tests, exhibiting good stability and reusability. The improved photocatalytic performance of TiO2/CRFs materials is attributed to the natural carbon and nitrogen element doping of TiO2/CRFs and its morphology, which reduces the compounding of photogenerated electron-hole pairs and narrows the TiO2 band gap, while the multiple reflections of visible light in the pore channels enhance the visible light absorption of the materials. Furthermore, the large specific surface area provides abundant reaction sites for adsorbed reactants. This paper provides the experimental basis for the application of waste rabbit biomass carbon composites in photocatalytic degradation field.

Development of Monodisperse Mesoporous Microballs Composed of Decahedral Anatase Nanocrystals

Mesoporous monodisperse microballs of amorphous titania were prepared from solution of absolute ethanol, tetrabutyl titanate (TBOT) and potassium chloride via a sub-zero sol–gel route. The as-obtained microballs were used as the precursor in an alcohothermal (ethanol with a small amount of water) process to synthesize monodisperse mesoporous microballs built of decahedral anatase nanocrystals. FE-SEM observation and XRD analysis have confirmed that the formed decahedral anatase-rich powder retained the original spherical morphology of the precursor. Importantly, a hierarchical structure composed of faceted anatase has been achieved under “green” conditions, i.e., fluorine-free. Additionally, the hysteresis loops (BET results) have confirmed the existence of mesopores. Interestingly, faceted microballs show noticeable photocatalytic activity under UV/vis irradiation for hydrogen generation without any co-catalyst use, reaching almost forty times higher activity than that by famous commercial titania photocatalyst—P25. It has been proposed that enhanced photocatalytic performance is caused by mesoporous structure and co-existence of two kinds of facets, i.e., {001} and {101}, and thus hindered charge carriers’ recombination.

Insights into biobased epoxidized fatty acid isobutyl esters from biodiesel: Preparation and application as plasticizer

Biodiesel was used to prepare epoxidized fatty acid isobutyl esters (Ep-FABEs) as a biobased plasticizer in this work. Transesterification of biodiesel with isobutanol catalyzed by tetrabutyl titanate was carried out in a gas-liquid tower reactor. The conversion achieved nearly 100% within 5 h under the reaction temperature, the mass ratio of catalyst to fatty acid methyl esters (FAMEs), and isobutanol to FAMEs total molar ratio of 180 °C, 0.4 %(mass), and 5.4:1, respectively. In addition, kinetic model of the transesterification reaction was developed at 150–190 °C. The calculated activation energy was 48.93 kJ·mol−1. Then, the epoxidation of obtained fatty acid isobutyl esters (FABEs) was conducted in the presence of formic acid and hydrogen peroxide. The Ep-FABEs was further analyzed for its plasticizing effectiveness to replace dioctyl phthalate (DOP) and compared with conventional epoxy plasticizer epoxidized fatty acid methyl esters (Ep-FAMEs). The results indicated that the thermal stability and mechanical properties of PVC films with Ep-FABEs plasticizer were significantly improved compared with those plasticized with DOP. In addition, the extraction resistance and migration stability of Ep-FABEs were better than those of Ep-FAMEs. Overall, the prepared Ep-FABEs via structural modification of biodiesel proved to be a promising biobased plasticizer.

Synergistic effects of a half‐cage and cage structure phosphorus and nitrogen‐containing POSS with tetrabutyl titanate on flame retardancy of vinyl epoxy resins

AbstractTo improve the flame retardancy of vinyl epoxy (VE) resins more effectively, a half‐cage and cage structure polyhedral oligomeric silsesquioxanes (P/N‐POSS) containing phosphorus and nitrogen was synthesized by a one‐step Kabachnik‐Fields reaction from paraformaldehyde, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and 3‐aminopropyltriethoxysilane. It was then blended with tetrabutyl titanate (TBT) in VE resins to construct a phosphorus‐nitrogen‐silicon‐titanium synergy flame retardant system. P/N‐POSS was well dispersed in the VE matrix at low loadings (≤4 wt%). With the addition of only 4 wt% P/N‐POSS and 0.2 wt% TBT, the LOI value reached 29.2 and the UL‐94 grade passed V‐1 rating. Moreover, compared with VE‐0, the peak heat release rate, total heat release, smoke production rate and total smoke production decreased significantly. The investigations on pyrolysis volatiles and char residue of cured VE composites revealed that the excellent flame retardancy of the VE composites were due to the superior free radical capturing ability, the dilution effect of P/N‐POSS in the gas phase, and the promoting the carbonation effect of P/N‐POSS, the catalyzing char formation ability of TBT in the condensed phase. Meanwhile, VE composites exhibited improved mechanical properties, thermal stabilities and retained the low viscosity and good processability of VE resins.

Highly stretchable multifunctional polymer ionic conductor with high conductivity based on organic-inorganic dual networks

Ionogels based on ionic liquids have attracted great attention in the field of energy storage and sensing due to their intrinsic advantages, including good thermal stability, low flammability and volatility, and favorable electrochemical properties. However, the introduction of ionic liquids usually sacrifices the mechanical properties of ionogels, such as stretchability and strength. Herein, inspired by reinforced concrete structures, an ionogel with rigid inorganic and flexible organic interpenetrating dual network is created, which exhibits high mechanical strength, excellent elongation (nearly 900%), good elasticity and high room temperature ionic conductivity (1.34 mS cm−1) by exploring the synergistic effect between the rigid and flexible components. Such a highly stretchable conductive organic–inorganic dual network is constructed through non-hydrolyzed sol–gel reaction of tetrabutyl titanate and in situ polymerization of butyl acrylate through UV irradiation. Impressively, the assembled energy stroage device (lithium-ion batteries) based on the ionogel exhibits over 1000 stable cycles with average Columbic efficiency of ∼ 100%, and excellent rate property. The resulting stretchable lithium-ion battery can power an LED at 50% strain. The ionogel, as ionic skin, also shows highly repeatable electrical responses in reciprocal deformation cycles. In terms of the above unusual features, the as-perpared ionogel manifests great promise for versatile applications in the field of flexible electronics.

Electrochemical aptasensing strategy based on a multivariate polymertitanium-metal-organic framework for zearalenone analysis

An electrochemical aptasensing strategy was developed with a novel bioplatform based on a multivariate titanium metal–organic framework, i.e. MTV polyMOF(Ti), to detect zearalenone (ZEN). MTV polyMOF(Ti) was prepared by using mixed linkers of polyether polymer (pbdc-xa or L8, pbdc = poly(1,4-benzenedicarboxylate) and 1,4-benzenedicarboxylic acid (H2bdc or L0) as well as tetrabutyl titanate as nodes (MTV polyMOF(Ti)-L8,0). Compared with Ti-MOFs synthesized by using the single ligand of L8 or L0, MTV polyMOF(Ti)-L8,0 shows more porous structure assembled with multilayered nanosheets. In light of the improved electrochemical activity and strong bioaffinity to the aptamer, the aptasensor based on MTV polyMOF(Ti)-L8,0 shows excellent performance for detecting ZEN with the ultralow detection limit at fg mL−1 level in the linear range of 10 fg mL−1 to 10 ng mL−1, along with good selectivity, reproducibility, stability, regenerability, and applicability.

Comparison between cotton fiber and cellulose powder for wastewater treatment efficiency with nano-crystalline TiO2 by sono-synthesis

PurposeThe main purpose of this study was to prepare the cotton fibers and cellulose powder by a layer of nano-crystalline-titanium dioxide (TiO2) using the sol-gel sono-synthesis method to clean the wastewater containing reactive dye. Moreover, TiO2 nano-materials are remarkable due to their photoactive properties and valuable applications in wastewater treatment.Design/methodology/approachIn this research, TiO2 was synthesized and deposited effectively on cotton fibers and cellulose powder using ultrasound-assisted coating. Further, tetra butyl titanate was used as a precursor to the synthesis of TiO2 nanoparticles. Reactive dye (red 195) was used in this study. X-ray Diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy were performed to prove the aptitude for the formation of crystal TiO2 on the cotton fibers and cellulose powder along with TiO2 nanoparticles as well as to analyze the chemical structure. Decoloration of the wastewater was investigated through ultraviolet (UV-Visible) light at 30 min.FindingsThe experimental results revealed that the decolorization was completed at 2.0 min with the cellulose nano TiO2 treatment whereas cotton nano TiO2 treated solution contained reactive dyestuffs even after the treatment of 2 min. This was the fastest method up to now than all reported methods for sustainable decolorization of wastewater by absorption. Furthermore, this study explored that the cellulose TiO2 nano-composite was more effective than the cotton TiO2 nano-composite of decoloration wastewater for the eco-friendly remedy.Research limitations/implicationsCotton fibers and cellulose powder with nano-TiO2, and only reactive dye (red 195) were tested.Practical implicationsWith reactive dye-containing wastewater, it seems to be easier to get rid of the dye than to retain it, especially from dyeing of yarn, fabric, apparel, and as well as other sectors where dyestuffs are used.Social implicationsThis research would help to reduce pollution in the environment as well as save energy and cost.Originality/valueDecoloration of wastewater treatment is an essential new track with nano-crystalline TiO2 to fast and efficient cleaning of reactive dyes containing wastewater used as a raw material.

Preparation of nano-TiN powders by Ni-catalysed carbothermal reduction nitridation

TiN nanoparticles were prepared at 900–1100 °C by Ni-catalysed carbothermal reduction nitridation from sol-gel using tetrabutyl titanate, citric acid monohydrate and nickel chloride hexahydrate as starting materials. The catalytic effects of nickel on the carbothermal reduction nitridation of xerogels were investigated. Ni has a crucial promoting effect on the carbothermal reduction reaction of the xerogels and visibly enhanced carbothermal reduction and nitridation reactions. The dry gel with 5% NiCl2 was added to obtain nano-TiN at 900 °C. The transmission electron microscopy analysis and Materials Studio simulation results showed that the facilitating effect of Ni on carbothermal reduction nitridation reaction was ascribed to the provision of heterogeneous nucleation sites for amorphous titania, promoting crystallisation and adsorption of N2, resulting in its smooth dissociation into highly active N atoms and consequently enhancing the carbothermal reduction nitridation.

Tunable microwave absorption band via rational design of C@TiC nanospheres

To effectively tune material's microwave absorption band, it is necessary to build a special structure and composition. Titanium carbide nanoparticles decorated carbon nanospheres (C@TiC) were prepared by using carbon nanospheres as a initial structure-directing agent, and their absorption band was tuned by rational design of TiC content. With increasing dosage of tetrabutyl titanate (TBT), absorption band of C@TiC dispersed in paraffin (30 wt%) gradually shifted from Ku to S-band, realizing the adjustment of absorption band. For example, when the amount of TBT was 1.0, 1.5 and 2.0 mL, the minimum reflection loss (RL) of C@TiC was about −49.8, −52.4 and −50.3 dB at 17.4, 13.1 and 6.6 GHz, respectively. Excellent performance was attributed to good impedance match and synergistic effect between carbon spheres and TiC nanoparticles. This in-situ phase transition induced nanoheterostructure would provide a way for microwave absorbers with tunable band.

Structures and photocatalytic activity of α-Fe2O3@TiO2 core - shell nanoparticles

We successfully fabricated the ellipsoidal α-Fe2O3@TiO2 nanoparticles (NPs) by modified Stöber method and 3D flower-like α-Fe2O3@TiO2 NPs by solvothermal method, using tetrabutyl titanate (TBOT) as the titanium precursor. These as-obtained α-Fe2O3@TiO2 NPs were calcined at 500 °C, and anatase TiO2 were uniformly deposited on surface of α-Fe2O3 cores. Due to the heterojunction effects, α-Fe2O3@TiO2 NPs exhibited much stronger optical absorption in ultraviolet–visible (UV–Vis) district. For degradation of Rhodamine B (RhB), 3D flower-like α-Fe2O3@TiO2 NPs displayed much higher photocatalytic activity than that of pure α-Fe2O3 and TiO2 NPs. Finally, the photocatalytic mechanism of α-Fe2O3@TiO2 NPs was proposed and explained.

Preparation and performance study of V2O5/TiO2 catalysts supported on ceramic filter

As the country pays more and more attention to air pollution, the ceramic filter catalyst that can achieve the effects of dust removal and NO reduction simultaneously has a promising prospect. In this paper, ceramic fiber filter supported catalyst was prepared by impregnation method and tetrabutyl titanate method. The effects of vanadium content, space velocity, temperature, and tetrabutyl titanate concentration on the NO conversion of ceramic fiber catalysts were studied, and various physical and chemical methods were used for characterization. The results show that ceramic fiber had excellent multi-dimensional space and bridging structure. The NO conversion of impregnation catalyst and tetrabutyl titanate catalyst increased with the increase of vanadium content and tetrabutyl titanate concentration; At 6700h−1 and a temperature of 300°C, both catalysts can reached the highest catalytic efficiency, tetrabutyl titanate method catalyst was 93.67%. The tetrabutyl titanate catalyst can be loaded more evenly and the filtration pressure drop of the catalyst was smaller than that of the impregnation catalyst. The filtration pressure drop was increased by about 20% compared with the unsupported ceramic fiber.

A simple method for preparation of lignin/TiO2 nanocomposites by sulfonation degree regulation and their application in polyurethane films.

The waterborne polyurethane (WPU) exposed to outdoor environment for a long time are more likely to reduce their mechanical performance and service life. This work describes a simple and effective method to obtain the homogeneous lignin/TiO2 nanocomposite as the anti-UV additive to improve the applicability of WPU. The SKLs/TiO2 were prepared by the gradient sulfonation kraft lignin (SKLs) and tetrabutyl titanate. The particle morphology and hybrid structure of SKLs/TiO2 are characterized by FT-IR, zeta potential analysis, XPS, TG and SEM. Interestingly, it was found that the change of π-π interactions and electrostatic repulsion between SKL molecules effected the forming of SKLs/TiO2 nanocomposite. The lignin content and morphology of SKLs/TiO2 nanocomposite could be controlled by regulating the sulfonate group content on lignin molecular. Furthermore, the SKLs/TiO2 nanocomposites was successfully applied on water polyurethane film as the additive, when SKLs/TiO2 content increased from 0wt% to 5.0wt%, the tensile strength increased 43%, the elongation at break increased from 240.0% to 352.0% and the UV transmittance reduced from 87% to 1.7% below 400nm, which greatly improved the UV resistance and mechanical properties. The results of this study are of significant and practical importance to the high-value-added utilization of lignin.

Compatibilization, processing and characterization of poly(butylene adipate terephthalate)/polylactide (PBAT/PLA) blends

A blend of poly(butylene adipate terephthalate) (PBAT) and polylactide (PLA) is a combination of biodegradable materials. This study aims to prepare compatibilized PBAT/PLA in a cost-effective and timesaving way and to process the material into blown films by fine-tuning the processing parameters. First, a catalyst masterbatch is prepared by transesterification of PBAT and PLA in the presence of tetrabutyl titanate (TBT) as a catalyst. This is followed by the compounding of the two polymer types in combination with the catalyst masterbatch. Third, the compounds are processed into blown films and panels. The processing parameters for film blowing are set to reduce the anisotropy. Finally, the material properties are evaluated such as mechanical tests. The fine-tuning of parameter settings including the blow-up ratio and draw-down ratio results in a higher degree of isotropy of the blown film. By adding the catalyst masterbatch (2 wt%, which corresponds to TBT of approximately 0.002 wt% with copolymers formed) in combination with the fine-tuning of parameter settings, the samples achieved a significant improvement on the material properties. The morphology of the cryogenically fractured panel samples shows a decrease in the diameter of the dispersed phase. In the cross and machine directions, the elongation at break increased by 85 and 93%, and the trouser tear propagation resistance increased by 2.4 and 10 N mm−1, respectively. Furthermore, both the elongation at break and the trouser tear propagation of the blown films achieved a higher degree of isotropy.

Optimization of Melt-mixing Transesterifi cation of Polylactide by Polyethylene Glycol Employing Response Surface Methodology

A process for preparing polylactide-block-polyethylene glycol (PLA-b-PEG) copolymers has been developed and optimized by employing a transesterifi cation reaction in a melt-mixing process. The reaction was carried out in a counter-rotating mixer unit, using polyethylene glycol (PEG) and tetrabutyl titanate (TBT) catalyst. The effects of PEG weight percentage, catalyst contents, temperatures, and rotor speeds on chemical structures of the resulting PLA-b-PEG were examined, in terms of number average molecular weight (Mn), weight average molecular weight (Mw), in-chain PEG contents (wt.% PEG), and specifi c mechanical energy (SME) imparted by the mixer. The process parameters were optimized using a central composite rotatable design (CCRD) response surface methodology (RSM). The CCRD was designed with four variables at three levels of variations (-1, 0, -1), four replicates center point, and a redundancy factor (α) of 2.000. The responses (Mn, Mw, wt.% PEG, and SME) from 28 experimental trials were analyzed by a multiple linear regression fi tting, a second-order equation, and the RSM model. Mn and Mw of the products were determined by gel permeation chromatography (GPC). The in-chain PEG content was examined by nuclear magnetic resonance (1H-NMR) spectroscopy. The results show that the PEG weight percentage and the reaction temperature signifi cantly affect (P< 0.05) Mw and Mn of the products, which are drastically decreased with an increase in the PEG weight percentage and temperature. A quadratic interaction is observed between the PEG weight percentage and temperature, indicating that high reaction temperature leads to lower PEG conversions, due to undesirable competing thermal-oxidative degradations of PEG in the presence of the catalyst. Optimum operating conditions on the PEG weight percentage, catalyst contents, temperatures, and rotor speed for obtaining high Mw with high wt.% PEG was identifi ed. Although the optimal conditions are observed at the boundary level, the model serves as a platform for effective preparation of PLA-b- PEG copolymers with designed molecular weight and chemical structures. Further optimization of the model may be conducted by extending the range of independent factor levels. The resulting fl exible PLA-b-PEG copolymers, with tunable structures and properties, have high potential for use as singlecomponent degradable bioplastics with excellent mechanical properties, plasticizers, or toughening agent for enhancing PLA’s toughness.

One-pot synthesis of C-modified and N-doped TiO2 for enhanced visible-light photocatalytic activity

Brand-new catalyst of C-modified and N-doped TiO2 (T3FN1) were synthesized by the hydro-thermal method using Tetrabutyl titanate (TBOT) and feathers of chicken as the precursor. It was found that thanks to the abundant TiO2 nanoparticles (anatase phase) distribution around the outer surface of feathers template, the catalyst displayed a typical 3D surface folded rod-shaped micron structure. After 30 min visible-light illumination, the degradation rate of TCH reached 89.8% with T3FN1, 1.52 times and 2.62 times higher than that of TiO2 without template (T3) and P25, respectively. Mechanism studies revealed that chicken feathers were used as natural organic templates to increase the dispersity of TiO2 meanwhile nitrogen in it was directly doped into TiO2 to improve the catalysts’ response to visible light. Beyond that, carbon of chicken feathers can be utilized directly as the transmission medium for electric charges to improve the spatial separation of photo-induced carriers. Moreover, with a wide pH range of adaptability and stability, the degradation rate of TCH by T3FN1 can still reach 83.15% after 5 cycles. Given its unique structure and photocatalytic performance, the catalyst has great potential in practical wastewater treatment.

Significant Improvement of Photocatalytic Activity of TiO2/g–C3N4 Composite Synthesized by the Aiding of Hydrothermal Method

g–C3N4 nanosheets were first synthesized by calcining the mixture of hydrochloric acid-pretreated melamine and ammonium chloride. Then, by the aiding of solvothermal method and hydrofluoric acid as morphology modifier, 001-TiO2/g–C3N4 (TCN-X, [Formula: see text], 3, 2, 1) nanocomposites were synthesized using g–C3N4 nanosheets and tetrabutyl titanate, with the mass ratio of g–C3N4 to TiO2 was 5:1, 3:1, 2:1 and 1:1, respectively. The as-synthesized samples were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption method, ultraviolet–visible diffuse reflectance spectrum, photoluminescence spectrum, etc. Their photocatalytic properties were evaluated under visible light irradiation with rhodamine B (RhB) as the target pollutant. The results reveal that the TCN-3 composites had a large specific surface area of 67.38[Formula: see text]m2/g and consisted of g–C3N4 nanosheets and anatase TiO2 crystals about 10–20[Formula: see text]nm in size. The (001) crystal planes of TiO2 can be easily observed in TCN-X composites. All TiO2/g–C3N4 composites exhibited excellent photocatalytic activity compared with the pure g–C3N4 did. The photocatalytic property of TCN-X samples varied with the mass ratio of g–C3N4to TiO2, and TCN-3 presented the optimum photocatalytic performance. In total, 50[Formula: see text]mg of TCN-3 completely degraded 50[Formula: see text]mL and 100[Formula: see text]mL of RhB solution (10[Formula: see text]mg/L) in 15[Formula: see text]min and 40[Formula: see text]min, respectively. The reaction rate constant of TCN-3 was 6.7 times as large as that of pure g–C3N4. TCN-3 also presented outstanding activity for the photocatalytic degradation of the colorless tetracycline solution. The significant improvement in photocatalytic activity of TCN-3 was attributed to the evenly distribution of TiO2 on g–C3N4, the enhanced specific surface area and the construction of 001-TiO2/g–C3N4 heterojunction between the g–C3N4 nanosheets and the (001) crystal planes of anatase TiO2, which greatly reduced the recombination rate of the photo-generated electron and hole.

Ultrasonic-driven polycondensation nonaqueous precipitation synthesis of Ba0.7Sr0.3TiO3 ceramics

Ba0.7Sr0.3TiO3 ceramics have excellent electrical performance and wide applications in sensors, capacitors, dynamic random access memory, and so on. High-quality Ba0.7Sr0.3TiO3 powders preparation is the premise and basis for obtaining Ba0.7Sr0.3TiO3 ceramics with excellent properties. Monodispersed Ba0.7Sr0.3TiO3 powders were synthesized using a novel ultrasonic-driven polycondensation nonaqueous precipitation method with tetrabutyl titanate, anhydrous barium acetate, and anhydrous strontium acetate as precursor materials and glycol as the solvent. Ultrasonic irradiation promotes the polycondensation of raw materials; Ba–O–Ti and Sr–O–Ti bonds form in the precipitate, facilitating low-temperature synthesis of Ba0.7Sr0.3TiO3 at 550 °C. Ultrasonic irradiation also assists in the monodispersing of precipitates and BST powders and low-temperature sintering, and considerable properties of Ba0.7Sr0.3TiO3 ceramics. The Ba0.7Sr0.3TiO3 powder and ceramic particle sizes are approximately 30–50 nm and 100–150 nm, respectively. The proposed ultrasonic-driven polycondensation nonaqueous precipitation method is expected to be widely used for preparation of ceramic powders.

Effect of Process Parameters on the Microstructure and Performance of TiO2-Loaded Activated Carbon.

In this study, the visible-light-driven photocatalytic regeneration performance of TiO2-loaded activated carbon (TiO2/AC) was effectively improved. By carefully controlling the activation condition at 700 °C for 2 h with a 60% H3PO4 concentration and 3:1 TBT (tetrabutyl titanate) impregnation ratio, 90.5% of methylene blue (50 mg/L) was removed within 2 h by a low-dose TiO2/AC (0.5 g/L), which was much higher than those obtained in previous studies on TiO2/AC. Moreover, the effects of process variables on the microstructure and performance of TiO2/AC were systematically investigated. The results showed that (1) the long period of activation time effectively inhibited the photogenerated charge carrier recombination and enhanced the regeneration performance of samples; (2) the photogenerated charge carrier recombination rate was lowered initially and then increased as the temperature ascended, whereas the pore volume showed an opposite variation tendency, and thus the adsorption and regeneration performances of samples were improved at 500–700 °C and then weakened at 800 °C; (3) the increase of H3PO4 concentration effectively inhibited the charge carrier recombination and had an improvement in the adsorption and regeneration performances of samples; and (4) the photogenerated charge carrier recombination rate and bandgap value of samples decreased initially and then increased with increasing TBT mass ratio, so the regeneration performances of samples were improved initially and then lowered.