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Ilmenite (FeTiO3) is a suitable mineral to produce titanium dioxide (TiO2) for photocatalyst applications. Therefore, this research was conducted to synthesize TiO2 material from titanium oxysulfate (TiOSO4) extracted from Indonesia local ilmenite mineral (FeTiO3) and to modify this material into TiO2 nanotubes through a hydrothermal process at 150 °C for 24 hours followed by a post-hydrothermal treatment with temperature variations of 80,100, 120, and 150 °C for 12 hours. The purpose was to investigate the effect of the post-hydrothermal variations on the crystal structure, morphology, and optical properties of the TiO2 nanotubes produced. It was discovered from the scanning electron microscopy (SEM) observations that the TiO2 nanotube was successfully derived from the ilmenite precursor. Moreover, the X-Ray diffraction (XRD) analysis of the nanotube crystal structure showed that post-hydrothermal treatment enhanced the crystallinity of the anatase TiO2 phase even though the sodium titanate phase was observed to exist in the structure. The increase in the post-hydrothermal temperature from 80 to 150 °C was also discovered to have led to: 1) a reduction in the unit cell volume from 136.37 to 132.31 Å3 and a decrease in the lattice constant c from 9.519 to 9.426 Å; 2) an increase in density from 7.783 to 8.081 gr/cm3 as well as in the crystallite size from 19.185 to 25.745 nm; 3) a decrease in the bandgap energy (Eg), from 3.33 to 3.02 eV. These characteristics further indicate the ability of the photocatalytic performance of the nanotubes to enhance the degradation efficiency from 87.69 to 97.11 %. This means the TiO2 nanotubes extracted from local FeTiO3 can provide the expected crystal structure and photocatalytic performance, Ільменіт (FeTiO3) є підходящим мінералом для отримання діоксиду титану (TiO2) для фотокаталізаторів. Тому дане дослідження було проведено для синтезу матеріалу TiO2 з оксисульфату титану (TiOSO4), вилученого з місцевого індонезійського мінералу ільменіту (FeTiO3) та модифікації цього матеріалу в нанотрубки TiO2 за допомогою гідротермального процесу при 150 °C протягом 24 годин з подальшою постгідротермальною обробкою зі змінами температури 80, 100, 120 і 150 °C протягом 12 годин. Метою роботи було вивчення впливу постгідротермальних змін на кристалічну структуру, морфологію та оптичні властивості отриманих нанотрубок TiO2. За допомогою скануючої електронної мікроскопії (СЕМ) було виявлено, що нанотрубка TiO2 була успішно отримана з попередника ільменіту. Крім того, рентгеноструктурний аналіз (РСА) кристалічної структури нанотрубки показав, що постгідротермальна обробка підвищує кристалічність фази анатазу TiO2, незважаючи на присутність у структурі фази титанату натрію. Було також виявлено, що підвищення постгідротермальної температури з 80 до 150 °C призвело до: 1) зменшення обсягу елементарної комірки з 136,37 до 132,31 Å3 та зменшення постійної решітки c з 9,519 до 9,426 Å; 2) збільшення щільності з 7,783 до 8,081 г/см3, а також розміру кристалітів з 19,185 до 25,745 нм; 3) зменшення ширини забороненої зони (Eg) з 3,33 до 3,02 еВ. Дані властивості додатково вказують на здатність фотокаталітичних характеристик нанотрубок підвищувати ефективність розкладання з 87,69 до 97,11 %. Це означає, що нанотрубки TiO2, вилучені з місцевого FeTiO3, можуть забезпечити бажану кристалічну структуру та фотокаталітичні характеристики

While the ever-increasing energy crisis for sustainable and renewable energy sources has prompted the development of innovative materials for photoelectrochemical water oxidation, the techniques to...

The technology development of electrochemical energy storage devices including lithium-ion battery is urgently needed to support the increased demand for renewable energy and production growth of portable electronic devices. Extensive research on nanostructural engineering aims to improve battery performance in terms of capacity, energy density, cycling ability, and Coulombic efficiency. This review describes the concept of atomic layer deposition (ALD) and focuses on ALD for Li-ion battery. Within the last few years, interest in the nanostructured materials synthesized by ALD to enhance battery performance has rapidly improved. Given the urgent requirement for reliable materials for high battery performance, ALD is a robust method for developing and fabricating nanostructure materials for next-generation Li-ion batteries, especially in the design of anode and cathode electrodes of the batteries.

In this work, the photoelectrochemical (PEC) properties of TiO2 nanotube arrays (NTAs) were enhanced by forming heterostructures with non-substituted covalent organic frameworks (H-COFs) and fluoro...

Large-clearance TiO2 nanotube arrays (LTAs) were synthesized by anodization, and evenly distributed P25 nanoparticles (P25 NPs) decorated on this were prepared by the hydrothermal treatment. The effect of P25 concentrations on the morphology of LATs was studied. LTAs decorated with P25 NPs (LTAs-P25) were loaded with ibuprofen (IBU), and the release properties were investigated. Interestingly, P25 NPs were successfully decorated on the surface of LTAs, with an optimal concentration of 1.2 × 10 − 3 M. The total amount of drug released from LTAs increased by 49.5% compared to that from TiO2 nanotube arrays without large clearance. LTAs-P25 provided a lower burst and longer release time.

Herein, a heterostructure of MoS2/CdS/TiO2 nanotube arrays is constructed by successive ionic layer adsorption/reaction of CdS and dipping-assembly of MoS2 on the vertically oriented TiO2 nanotubes prepared by anodization method. The heterostructure is extensively investigated in terms of the composition, morphology, structural, and optical properties. It is observed that the co-modification of TiO2 nanotube arrays with CdS and MoS2 significantly enhances the visible light response and boosts the facile photo-generated electrons’ transfer and charge separation efficiencies. Therefore, the prepared heterostructure photo-anode exhibits significantly enhanced photoelectrochemical properties including photocurrent, open circuit potential, and photo-conversion efficiencies compared with that of pure TiO2 nanotube arrays and CdS/TiO2 nanotube systems. Interestingly, it is found that the MoS2 coatings on the surface of CdS/TiO2 nanotube arrays greatly enhance their photoelectrochemical stability. The presented work demonstrates that MoS2/CdS/TiO2 nanotube heterostructures are a promising material for improved photoelectrochemical properties. A heterostructure of MoS2/CdS/TiO2 nanotube arrays was constructed by successive ionic layer adsorption/reaction of CdS and dipping-assembly of MoS2 on the vertically oriented TiO2 nanotube arrays, and their improved photoelectrochemical properties were demonstrated

The TiO2 nanotube arrays were prepared on Ti plate by anodizing technology, and then Co (OH)2 nanoparticles in-situ grew into TiO2 nanotubes with "Tube-particle bonding" nanocomposited structure. Co (OH)2 nanoparticles with a particle size of 40.5±8 nm were infiltrated in the TiO2 nanotube arrays, and the Co (OH)2 outside the tube presented a nanosheet structure. The specific capacitance of the Co (OH)2/TiO2 nanotube array composite reached 260 F/g at the current density~1 A/g. The capacity retention rate was 82.5 % after 2,000 cycles at the current density~5 A/g. The high-rate performance of the Co (OH)2/TiO2 nanotube array composite reached 210 F/g at the current density~10 A/g.

Because of importance the Ga alloys in dental applications, many attempts were done to improve the properties of this alloy. The current work involves addition of TiO2 nanotube powder to Galloy to improve some mechanical properties. These properties included hardness, compression, and creep. The characterization of prepared TiO2/Galloys with five wt% of TiO2 (1, 2, 3, 4, and 5 wt%) was done by XRD and SEM/EDS. The results showed that the hardness, compression, were increased with increasing percentage of added TiO2, while creep decrease. Some phases such as β-Sn, Ag2Ga and Ag9In4 were contributed to improve the properties of new TiO2/Galloy composites.

Electrochemically reduced TiO2 nanotube arrays (r-TiO2 NTA) have emerged as an alternative that can replace the dimensionally stable anode (DSA®) due to comparable performance for chlorine evolution reaction (ClER). However, previous studies have reported applications of r-TiO2 NTA for ClER only under limited conditions (concentrated NaCl solution without other anions). Thus, the potential of r-TiO2 NTA for CIER has not yet been fully demonstrated. Therefore, this study focused on investigating ClER of r-TiO2 NTA under various parameters such chloride concentration (5–1,000 mM) and the presence of other anions (i.e., SO 4 2− , HPO 4 2− , and CO 3 2− ). The results suggest that, at low chloride concentration (5–50 mM NaCl), the r-TiO2 NTA exhibited higher performance for CIER (production rate of 3.35–9.82 mg l−1 min−1, current efficiency of 14.43–42.04%, energy consumption of 69.24–11.02 Wh g(Cl2)−1) than RuO2 (2.55–7.88 mg l−1 min−1, 11.07–33.85% and 77.29–6.84 Wh g(Cl2)−1, respectively). Additionally, other anions did not affect the ClER of r-TiO2 NTA more than RuO2. These can be explained by the indirect pathway of ClER in r-TiO2 NTA while the direct pathway of RuO2 was negatively affected by dilute chloride and other anions.

Antibiotic resistance has become a global crisis in recent years, while wastewater treatment plants (WWTPs) have been identified as a significant source of both antibiotic resistant bacteria (ARB) ...

The kinetics of the photoelectrochemical mineralization of p-nitrophenol (PNP) and p-methoxyphenol (PMP) on rutile:anatase TiO2 nanotube electrodes (% rutile: 0, 16, and 20) has been studied. Oxida...

This paper aims to disclose how the size of TiO2 Nanotubes affects the performance of Li-ion battery with TiO2 nanotubes as anode material. Firstly, TiO2 nanotubes of two different sizes were synthetized by hydrothermal method, namely, L-TiO2 nanotubes and S-TiO2 nanotubes. Next, the morphology, structure, cycle performance, rate performance, and electrochemical performance of the button batteries respectively assembled with L-TiO2 nanotubes and S-TiO2 nanotubes as anode materials (L-battery and S-battery) were tested with a scanning electron microscope (SEM), a transmission electron microscope (TEM), an X-ray diffractometer (XRD), a battery test system, and an electrochemical workstation. The results show that S-battery has better specific discharge capacity (SDC), cycle stability and rate performance than L-battery. The initial DSC of S-battery was as high as 262.6mAh/g; after 100 cycles, the DSC of that battery was still 250.5mAh/g, down by only 0.046%. Even if the rate increased to 2C, the DSC of the battery was maintained at 151.8mAh/g.

The Co3O4 decorated TiO2 nanotube arrays(NTAs) coatings are fabricated by the combination of anodization and impregnating methods. It is found that the introduction of Co3O4 can reduce the diffraction intensity of (101) plane of the TiO2 and accelerate the separation of photogenerated electron/hole pairs. In addition, the open circuit potential(OCP) and the corrosion potential of 304 stainless steel(304SS) with or without Co3O4 decorated TiO2 NTAs were measured under visible light, which indicated the 304SS coupled with Co3O4 decorated TiO2 NTAs had better anticorrosion performance than that of the 304SS or the 304SS coupled with pure TiO2 NTAs. The enhancement of the cathodic protection performance of the Co3O4 decorated TiO2 NTAs can be ascribed to the matched energy levels and strong interaction between Co3O4 and TiO2 NTAs, and the improvement of light absorption.

This study compared the topography of different titanium surface structures (TiO2 nanotube and grain) with similar elemental compositions (TiO2 and fluorine [F]) on the Ti surface. High magnification indicated that the surfaces of the control and etching groups were similar to each other in a flat, smooth form. The group anodized for 1 h was observed with TiO2 nanotubes organized very neatly and regularly. In the group anodized for 30 min after etching, uneven wave and nanopore structures were observed. In addition, MTT assay showed that the F of the surface did not adversely affect cell viability, and the initial cell adhesion was increased in the 2.8% F‐incorporated TiO2 nanograin. At the edge of adherent cells, filopodia were observed in spreading form on the surfaces of the anodizing and two‐step processing groups, and they were observed in a branch shape in the control and etching groups. Moreover, cell adhesion molecule and osteogenesis marker expression was increased at the F‐incorporated TiO2 nanostructure. In addition, it was found that the expression of p‐extracellular signal‐regulated kinase (ERK) and p‐cAMP response element‐binding protein (CREB) increased in the TiO2 nanograin with the nanopore surface compared to the micro rough and nanotube surfaces relative to the osteogenic‐related gene expression patterns. As a result, this study confirmed that the topographic structure of the surface is more affected by osteogenic differentiation than the pore size and that differentiation by specific surface composition components is by CREB. Thus, the synergy effect of osteogenic differentiation was confirmed by the simultaneous activation of CREB/ERK.

This work reports the growth of stable TiO2 nanotube arrays on flexible Kapton substrates by electrochemical anodization of a sputtered Ti (titanium) film. Although such nanotubes are conventionall...

For improving the surface-enhanced Raman scattering (SERS) performance of nanomaterials to achieve trace detection of proteins and complex biological systems, structural and topographical control i...

Herein, hierarchical MoSe2/1D TiO2 nanotube layer structure was successfully fabricated in a simple and fast fashion and its photocatalytic and electrocatalytic properties were assessed. The novelty of this work lies in the utilization of Atomic Layer Deposition (ALD) technique to deposit MoSe2 nanosheets on 1D TiO2 nanotube layers. The photoelectrochemical and photo- and electrocatalytic properties were explored and optimized as a function of the MoSe2ALD cycles. ALD allowed precise control on MoSe2 nanosheet size, and in turn, on the surface structure, which is pivotal for efficient catalysts. The MoSe2 nanosheets grew on both inner and outer 1D TiO2 nanotube surface mainly perpendicularly oriented, maximizing the exposed active edges, an essential aspect to fully exploit the MoSe2 photo- and electrochemical properties. Outstanding photo- and electrocatalytic activity were recorded in both dye organic pollutant degradation and hydrogen evolution reaction applications, respectively. The excellent photocatalytic and electrochemical activity stems from the synergy between tailored ALD loading of MoSe2 nanosheets on 1D TiO2 nanotubular structure with high surface/volume ratio, which provided fast electron transfer and easy access to the MoSe2 active edges, boosting the catalytic activity. V této práci jsme vytvořili hybridní strukturu MoSe2 nanodestiček na 1D TiO2 nanotrubicových vrstvách jednoduchým a rychlým způsobem. Novost naší práce spočívá ve využití techniky depozice atomárních vrstev (ALD) pro deponování MoSe2 nanodestiček na 1D TiO2 nanotrubicové vrstvy. U výsledných materiálů jsme zhodnotili výsledné fotokatalytické a elektrokatalytické vlastnosti v závislosti na počtu použitých depozičních ALD cyklů. ALD umožnilo velmi precizní kontrolu velikosti MoSe2 nanodestiček a také mělo vliv na na jejich povrchovou strukturu, která je klíčový pro výsledné vlastnosti. Tyto nanodestičky rostly jak uvnitř trubic, tak na jejich externím povrchu, kolmo orientované k trubicovým stěnám, což vedlo k maximálnímu možnému obnažení aktivních center na hranách nanodestiček. Velmi vysoké foto- a elektrokatalytické aktivity byly dosaženy pro rozklad modelových organických látek a pro vývoj vodíku, respektive. Tyto výkony pramení ze synergie mezi MoSe2 nanodestičkami a 1D TiO2 nanotrubicovými vrstvami s vysokým poměrem dostupného povrchu/objemu, což umožnilo velmi dobrý přenos elektronů a snadný přístup reaktantů k aktivním centrům MoSe2 nanodestiček.

Photoelectrochemical biofuel cells can convert light and chemical energy into electrical energy using a dye-sensitized titania (TiO2) fluorine-doped tin oxide photoanode and a platinum-coated fluorine-doped tin oxide cathode. TiO2 of the photoanode serves both as a support for dyes and as an electron-transporting medium, the structure of which can limit electron trapping and charge transporting and then affect the performance of the photoelectrochemical biofuel cells. TiO2 nanotube array films have been shown to enhance the efficiencies of both charge collection and electron injection, and hence a vertically aligned TiO2 nanotube array is investigated as a conductor for the tetrakis(4-carboxyphenyl)porphyrin dye to construct a new two-compartment photoelectrochemical biofuel cell. The photoelectrochemical biofuel cell containing the TiO2 nanotube array photoanode yields a short-circuit (Isc) current of 110 μA and an open-circuit (Voc) potential of 1010 mV. In contrast, the photovoltaic parameters, Isc and Voc of the photoelectrochemical biofuel cell with the mesoporous TiO2 nanocrystal fluorine-doped tin oxide photoanode, are 96.96 μA and 740 mV, respectively. Photovoltaic measurements show that the maximum incident photon-to-collected electron conversion efficiency was 58% at 430 nm through the spectral range (400–800 nm) for the photoelectrochemical biofuel cell with the TiO2 nanotube array fluorine-doped tin oxide photoanode. These results revealed that the TiO2 nanotube array had great potential for the photoelectrochemical biofuel cells.

Metal oxide nanostructure hybrid materials have garnered focused attention for next-generation memory-based devices. TiO2 nanostructure hybrids dwell in that league of materials. In reference to th...

The different configurations of CdSe nanoparticles, Au nanocrystals and TiO2 nanotube arrays play an important role in the photoelectrochemical behavior and photoelectrocatalytic hydrogen production of this heterogeneous photoelectrode system. It is discovered that the photoelectrocatalytic hydrogen production of the TiO2–CdSe–Au photoelectrode (1.724 mmol g−1 h−1) is about 4 times that of the TiO2–Au–CdSe photoelectrode (0.430 mmol g−1 h−1) under visible light irradiation. From the comprehensive investigation of their photoelectrochemical behaviors, it is illustrated that the interfacial electrical field has distinct effects on the separation and transportation of photogenerated carriers in these heterostructure photoelectrodes. The directions of the interfacial electrical fields formed at TiO2–Au and Au–CdSe interfaces are opposite in the TiO2–Au–CdSe photoelectrode, which hinders the separation of photogenerated electron-hole pairs and subsequent transportation of photogenerated carriers. On the contrary, the directions of the interfacial electrical fields formed at TiO2–CdSe and CdSe–Au interfaces are identical in the TiO2–CdSe–Au photoelectrode, which promotes the separation of photogenerated excitons and subsequently enhances their transportation for enlarged photocurrent density. The results of photoelectrocatalytic hydrogen production also confirm our assumption.

Photon absorption, charge separation and transportation, and charge-induced reactions at the active sites are the main crucial factors involved in the photoelectrochemical (PEC) water splitting. He...

Quantitative analysis using laser desorption/ionization mass spectrometry (LDI-MS) has been limited because of the nonuniform distribution of analytes caused by the “coffee ring effect”. In this st...

Herein, a flame-assisted pyrolysis technique is developed for one-step in-situ construction of Cu2O/Cu/TiO2 nanotube arrays. The structure and morphology of the obtained samples are systematically characterized. Interestingly, UV–vis absorption spectroscopy reveals that the introduction of Cu2O and Cu considerably enhance light response of TiO2 nanotube arrays in the visible region. Moreover, the composited electrode shows enhanced photo-electrochemical activity. Compared with blank TiO2 nanotube arrays, not only the photocurrent and photo-voltage of composited electrodes are improved but also the stability is also enhanced. And, the maximum photo-conversion efficiency for composited electrode presents 4.71 folds larger than that of blank TiO2 electrode. This enhancement is due to the faster charge separation/transportation ability of Cu and visible light response of Cu2O. This research develops a novel and facile method for the in-situ fabrication of Cu2O/Cu/TiO2 nanotube arrays and demonstrates their improved utilization of solar energy.

Objectives:In this study, the treatment potential of ammonia in wastewater generated by S company odor removal process was tested by using electrochemical reactor with RuO2/Ti anode and TiO2 nanotube cathode. The effect of chlorine ion concentration and current density on ammonia oxidation were investigated by comparing the treatment efficiencies.Methods:380 mL of wastewater was electrolyzed for 3 h using 4 anodes and 5 cathodes and pH, NH3-N, NO3--N, and TN were measured and analyzed every 30 minutes.Results and Discussion:As the addition of chlorine ion increases, about 1,700 mg/L of ammonia in the wastewater was found to increase in oxidation reaction rate due to an increase in chlorine based oxidizing agent. An increase in chlorine based oxidizing agent leads to an increase in indirect oxidation. As a result, total nitrogen removal was increased. Ammonia oxidation rate was increased as the current density increased. Nitrate, ammonia oxidation byproduct, was accumulated at a current density from 20 to 40 mA/cm2. At higher than 50 mA/cm2, nitrate was accumulated for a while and then decreased. Total nitrogen removal rate increased as the current density increased. During electrochemical oxidation of ammonia to nitrate, hydroxyl ions were consumed by the reaction. The hydroxyl ion consumed during ammonia oxidation was less than that produced from nitrate reduction.Conclusions:Thus, ammonia in actual wastewater was completely removed using RuO2/Ti anode and TiO2 nanotube cathode and the possibility of reducing nitrate was confirmed. We confirmed the applicability of the two electrodes to the real industry.

The continuous emission of nitrous oxides contributes to the overall air pollution and deterioration of air quality. In particular, an effective NO2 sensor capable of low concentration detection fo...

Methyl formate is widely employed as one of the important organic intermediates in C1 chemistry and as an environmentally benign chemical in the emerging area of “green chemistry”. We here study the catalytic effectiveness of CuO/TiO2-nanotube nanocomposites for the direct synthesis of methyl formate via methanol photo-oxidation in this paper. The CuO/TiO2-nanotube nanocomposites with 7% CuO weight loading give a promising photocatalytic performance (over 93.3% methanol conversion and 89.4% methyl formate selectivity) at 25 °C under 365 nm UV irradiation. The turnover frequency and the apparent quantum efficiency reach up to 22.9 molmethanol gcat–1 h–1 and 57.6% over 7% CuO/TiO2-nanotube, respectively, which is mainly because of the effective minimization of the recombination of photogenerated electrons and holes by the surface ultrasmall-sized CuO particles. Furthermore, these CuO/TiO2-nanotube nanocomposites exhibit excellent durability and robust nature during the catalytic processes of the methanol photo-oxidation to methyl formate. The experimental results demonstrate the promise of the robust CuO/TiO2 nanocomposites for efficient and green production of methyl formate, which may offer guidelines for the design of efficient catalysts for selective alcohol conversion to other valuable chemicals.

The present study addresses the issue of infection on and around titanium orthopaedic implants by modifying the Ti6Al4V implant surface with titania nanotubes via electrochemical anodisation follow...

TiO2 nanotube photonic crystals with a mass of oxygen vacancies (VO-TiO2 NTPCs) are prepared through a simple electrochemical reduction. The novel VO-TiO2 NTPCs produce a photocurrent density of 1.4 mA/cm2 at 0.22 V versus Ag/AgCl with Faradic efficiency of 100%, which is 1.75 times that of pristine TiO2NTPCs. The improved performance is contributed to the fact that the oxygen vacancies created by electrochemical reduction, which not only promote efficient utilization of the visible light absorption, but also increase electrical conductivity. This work will contribute to the design and fabrication of the TiO2nanotube-based photoelectric devices.

Macrophages are attracting increasing attention in promoting implant-mediated osteogenesis by modulating the microenvironment of the implant site. Biomaterial surface properties including topograph...

Ru- and Ti-based oxide electrocatalysts have been intensively studied for chlorine evolution reactions since their synergistic effect was demonstrated in commercial dimensionally stable anodes. Basically, oxide materials intrinsically possess a semiconducting nature; therefore, tuning conducting properties is important in achieving high electrocatalytic activity. Here, black TiO2 nanotube arrays deposited with RuO2 by pulsed electrodeposition are investigated as a three-dimensional supporting electrode for chlorine and hydrogen evolution. RuO2-loaded black titania achieves high chlorine evolution activity (10 and 100 mA cm−2 at 1.090 and 1.125 V vs. SCE) with a faradaic efficiency of 95.25% while RuO2-loaded titania has no activity, though hydrogen evolution reaction performance is similar. This suggests that the type of titania support affects the conducting property at anodic potentials and chlorine evolution activity. This work provides new insights into the importance of black titania materials in enhancing the electrocatalytic activity of anodic reactions.

TiO2 nanotubes (TNTs) were synthesized and modified using the anodization method in a glycerol and ammonium fluoride solution, which was followed by a thermal treatment. The second anodisation was continued by increasing anodizing voltage to deposit a film on the surface of titanium, which resulted in a free standing membrane based on of TNTs. The nanotubes were further characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The SEM result showed that the layer thickness of free standing membrane based on TNTs increased with an increase in the anodizing voltage; however, at high voltages, this layer was damaged. The XRD and FTIR results indicated the generation of TNT having an anatase crystal phase. The results of test for photoelectrochemical properties showed that the optimal conditions of anodizing voltage was 50 V maintained for 1 h.

TiO2 nanotubes (TiNTs)/graphite-like carbon nitride (g-C3N4) nanorod (NR) photocatalyst was synthesized by the droplet evaporation method followed by annealing. The aim of this research is to imple...

Au nanoparticles (NPs) were incorporated into the channels of freestanding TiO2 nanotube arrays (TNTAs) by an electrodeposition method and then applied to dye-sensitized solar cells (DSSCs) for light harvesting to improve the power conversion efficiency (PCE). The average size of Au NPs incorporated into TNTA channels was approximately 70 nm, and the extinction of the Au NPs by UV–vis spectra was approximately 530 nm, which is similar to the absorbance of the ruthenium dye (N719) used in DSSCs. The PCE of DSSCs based on TNTAs containing Au NPs increased to 6.80% from a PCE of 5.66% without Au NPs, an enhancement of 20.14% owing to light harvesting from the NP plasmonic and charging effects. However, the PCE of DSSCs based on TNTAs with excess Au NPs decreased from 6.80% to 5.49% due to aggregation of the Au NPs, which led to a decreased open-circuit voltage and fill factor.

On the basis of time-dependent density functional theory (TD-DFT) we performed first-principle calculations to predict optical properties and transition states of pristine, N- and S-doped, and N+S-codoped anatase TiO2 nanotubes of 1 nm-diameter. The host O atoms of the pristine TiO2 nanotube were substituted by N and S atoms to evaluate the influence of dopants on the photocatalytic properties of hollow titania nanostructures. The charge transition mechanism promoted by dopants positioned in the nanotube wall clearly demonstrates the constructive and destructive contributions to photoabsorption by means of calculated transition contribution maps. Based on the results of our calculations, we predict an increased visible-light-driven photoresponse in N- and S-doped and the N+S-codoped TiO2 nanotubes, enhancing the efficiency of hydrogen production in water-splitting applications.

Mixed-matrix membranes (MMMs) possess the unique properties and inherent characteristics of their component polymer and inorganic fillers, or other possible types of additives. However, the successful fabrication of compact and defect-free MMMs with a homogeneous filler distribution poses a major challenge, due to poor filler/polymer compatibility. In this study, we use two-dimensional multi-layered Ti3C2Tx MXene nanofillers to improve the compatibility and CO2/CH4 separation performance of cellulose triacetate (CTA)-based MMMs. CTA-based MMMs with TiO2-based 1D (nanotubes) and 0D (nanofillers) additives were also fabricated and tested for comparison. The high thermal stability, compact homogeneous structure, and stable long-term CO2/CH4 separation performance of the CTA-2D samples suggest the potential application of the membrane in bio/natural gas separation. The best results were obtained for the CTA-2D sample with a loading of 3 wt.%, which exhibited a 5-fold increase in CO2 permeability and 2-fold increase in CO2/CH4 selectivity, compared with the pristine CTA membrane, approaching the state-of-the-art Robeson 2008 upper bound. The dimensional (shape) effect on separation performance was determined as 2D > 1D > 0D. The use of lamellar stacked MXene with abundant surface-terminating groups not only prevents the aggregation of particles but also enhances the CO2 adsorption properties and provides additional transport channels, resulting in improved CO2 permeability and CO2/CH4 selectivity. ispartof: MEMBRANES vol:12 issue:10 ispartof: location:Switzerland status: published

Vertically aligned Fe, S, and Fe-S doped anatase TiO2 nanotube arrays are prepared by electrochemical anodization process using an organic electrolyte in which lactic acid is added as an additive. In the electrolyte, nanotube layers of greater length (12 μm) and high order with inner diameter of approx. 90 nm and outer diameter of approx. 170 nm are achieved. Doping of Fe, S, and Fe-S via simple wet impregnation method substituted Ti and O sites with Fe and S, which leads to enhance the rate performance at high discharge current densities. Discharge capacities of TiO2 tubes increased from 82 mAh g-1 (bare) to 165 mAh g-1 for Fe-S doped TiO2 at high current densities of 0.3 mAcm-2 after 100 cycles with exceptional capacity retention of 85% after 100 cycles. Owing to the enhancement of thermodynamic and kinetic properties by doping of Fe-S, Li-diffusion increas2ed resulting in remarkable discharge capacities of 143 mAh g-1 and 89 mAh g-1 at a current density of 7.4 mA cm-2 and 19 mA cm-2, respectively.

Bone marrow mesenchymal stem cells (BMSCs) play a critical role in bone formation and are extremely sensitive to external mechanical stimuli. Mechanical signals can regulate the biological behavior of cells on the surface of titanium-related prostheses and inducing osteogenic differentiation of BMSCs, which provides the integration of host bone and prosthesis benefits. But the mechanism is still unclear. In this study, BMSCs planted on the surface of TiO2 nanotubes were subjected to cyclic mechanical stress, and the related mechanisms were explored. The results of alkaline phosphatase staining, real-time PCR, and Western blot showed that cyclic mechanical stress can regulate the expression level of osteogenic differentiation markers in BMSCs on the surface of TiO2 nanotubes through Wnt/β-catenin. As an important member of the histone acetyltransferase family, GCN5 exerted regulatory effects on receiving mechanical signals. The results of the ChIP assay indicated that GCN5 could activate the Wnt promoter region. Hence, we concluded that the osteogenic differentiation ability of BMSCs on the surface of TiO2 nanotubes was enhanced under the stimulation of cyclic mechanical stress, and GCN5 mediated this process through Wnt/β-catenin.