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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...

Purpose Some systemic conditions, especially diabetes mellitus (DM), adversely affect dental implant success. This study aimed to investigate the effects of ibuprofen-loaded TiO2 nanotube (ILTN) dental implants in alloxan-induced diabetic rabbits. Methods Twenty-six New Zealand white rabbits were treated with alloxan monohydrate to induce DM. At 2 weeks following DM induction, 3 types of implants (sandblasted, large-grit, and acid-etched [SLA], ILTN, and machined) were placed into the proximal tibia in the 10 rabbits that survived following DM induction. Each type of implant was fitted randomly in 1 of the holes (round-robin method). The animals were administered alizarin (at 3 weeks) and calcein (at 6 weeks) as fluorescent bone markers, and were sacrificed at 8 weeks for radiographic and histomorphometric analyses. Results TiO2 nanotube arrays of ~70 nm in diameter and ~17 μm in thickness were obtained, and ibuprofen was loaded into the TiO2 nanotube arrays. A total of 26 rabbits were treated with alloxan monohydrate and only 10 rabbits survived. The 10 surviving rabbits showed a blood glucose level of 300 mg/dL or higher, and the implants were placed in these diabetic rabbits. The implant stability quotient (ISQ) and bone-to-implant contact (BIC) values were significantly higher in the ILTN group (ISQ: 61.8, BIC: 41.3%) and SLA group (ISQ: 62.6, BIC: 46.3%) than in the machined group (ISQ: 53.4, BIC: 20.2%), but the difference in the BIC percentage between the SLA and ILTN groups was not statistically significant (P=0.628). However, the bone area percentage was significantly higher in the ILTN group (78.0%) than in the SLA group (52.1%; P=0.000). Conclusions The ILTN dental implants showed better stability (ISQ) and BIC than the machined implants; however, these values were similar to the commercially used SLA implants in the 2-week diabetic rabbit model., Graphical Abstract

A modified confined catalyst with Pt nanoparticles on the interior and Fe2O3 on the exterior surface of TiO2 nanotubes (Pt-in/Fe2O3-TNTs) was prepared and investigated for catalyzing the oxidation of ethylene. Compared with the Pt-in/TNTs without Fe2O3 modification, the Pt-in/Fe2O3-TNTs exhibited a significantly enhanced activity, and the complete conversion temperature of ethylene decreased from 170 to 95 °C. X-ray photoelectron spectroscopy analysis indicated that the Pt nanoparticles were stabilized at higher oxidation states in the Pt-in/Fe2O3-TNT catalyst. It was proposed that the modification of Fe2O3 on the outer surface can tune the electronic state of the encapsulated Pt particles and accelerate the electrons transferred from Pt to Fe species via TiO2 nanotubes, thus improving the catalytic oxidation performance of the confined catalyst.

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 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...

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...

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...

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.

Purpose This systematic review and meta-analysis aims to synthesize evidence relating to the effects of TiO2 nanotubes on osseointegration in animal models. Materials and methods The focused question was "Does the preparation of TiO2 nanotubes on the surface of implants enhance osseointegration?" Searches were performed for relevant manuscripts up to September 2019 using the PubMed, Embase, Scopus and Google Scholar databases with terms such as "TiO2 nanotubes" in combination with "osseointegration", "osteogenic", "osteogenesis", and "bone regeneration". The titles, abstracts and full texts of the manuscripts were reviewed in accordance with the eligibility criteria. The meta-analysis were then performed to analyze the effects of TiO2 nanotubes in bone-implant contact (BIC) and biomechanical tests. Results Fourteen manuscripts were included for the systematic review and meta-analysis. Eleven studies showed that the results of a histological analysis, micro-CT evaluation and biomechanical tests were significantly higher near TiO2 than titanium. The meta-analysis demonstrating similar results in the BIC and biomechanical tests were obtained. The selected studies also showed the preferable nanotube diameter (70, 80, or 100 nm) to enhance osseointegration in BIC and/or bone area (BA). Conclusion TiO2 nanotubes, especially those with large diameters, enhanced osseointegration near titanium implants. Compared to bare nanotubes, TiO2 nanotube composite coatings resulted in higher osteogenic ability.

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...

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.

Tremendous progress has been made in power conversion efficiency (PCE) of thin-film photovoltaics over the past few years, yet most current high-efficient photoactive layer usually contains rare or toxic elements accompanied by expensive and complicated vacuum processes, which increases the cost and limits the scope of the applications in the long run. Here we present a synergistic effect of quantum effect of an earth-abundant and low toxic ultrafine Cu2ZnSnS4 (CZTS) quantum dots (QDs) and low charge recombination in one dimensional TiO2 nanotube arrays for optoelectronic devices. By ligands exchange, the as-obtained ultrafine CZTS QDs have been robustly anchored to a highly ordered TiO2 nanotube arrays (TNAs) to be served as a function layer in a simple QDs sensitized solar cells. Such ultrafine CZTS QDs based solar cells exhibit significant enhancement up to 457% in PCE compared to that of CZTS QDs with larger size. The CZTS QDs functionalized TNAs has also shown excellent charge transport capability with lower recombination rate than QDs sensitized TiO2 nanoparticles and it is expected to be used as a low-cost environment-friendly function layer for various potential optoelectronic applications.

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.

Freestanding TiO2 nanotube arrays (TNTAs) were prepared by an electrochemical method, and dye-sensitized solar cells (DSSCs) were fabricated with the open-ended freestanding TNTAs incorporated with...

Dye-sensitised solar cells (DSSCs) have been widely studied since their discovery; however, a number of problems should be solved to enhance their efficiency. We successfully fabricate Titanium oxi...

Enormous efforts have been devoted to the development of new catalysts or unique nanostructures with high activity and stability at low cost for oxygen evolution reaction (OER). Herein, we designed...

The desalination and purification of sea or brackish water by utilizing solar energy are considered to be the most feasible solutions to overcome the problems of water shortage and pollution. In this study, a bifunctional Cu2-xSe-decorated hierarchical TiO2 nanotube mesh (CTNM) was designed and synthesized successfully for both solar water evaporation and photodegradation. Cu2-xSe enhances solar light absorption and solar water evaporation performance as a low-cost absorber because of its localized surface plasmon resonance (LSPR) effect. Meanwhile, the formation of the p-Cu2-xSe/n-TiO2 heterojunction improves the photodegradation performance by increasing separation and transport of photogenerated charge carriers. Hence, CTNM has a relatively high solar water evaporation conversion efficiency of 83.06% and also can photodegrade 95% of methyl orange after 3 h under 2.5 kW m−2 simulated solar irradiation, which demonstrate the extremely high utilization ratio of solar energy of CTNM.

Recent evidence of exponential environmental degradation will demand a drastic shift in research and development toward exploiting alternative energy resources such as solar energy. Here, we report...

Although morphological disorder of nanotube structure is further down than the nanoparticular electrode, its density of traps are the hindering effects in the charge transport. In this study, crack-free TiO2 nanotube membranes, which obtained through a re-anodizing process, are fixed on transparent fluorine–tin-oxide glass by applying a few drops of Titanium Isopropoxide without needing the TiO2 powder paste. Front-side illuminated dye sensitized solar cells fabricated by undoped, N-doped and blue TiO2 nanotube membranes are investigated. The electrical characteristics of TiO2 nanotube based dye sensitized solar cells are followed by theoretical analysis using simple one-diode model. Morphology improvement is utilized to remove top irregular layers and the efficiency can be increased up to 56%. Annealing temperature, dopant, and tube orientation effects are examined on the cell efficiencies. The results show that elevating annealing temperature from 480 to 520 °C improve the cell efficiency up to 70%. Also, in the N-doped TiO2 nanotube membranes, improvement in efficiency is observed up to 40% as compared to undoped samples. Finally, different orientations of N-doped TiO2 nanotubes are studied and it is found that the through-hole morphology of N-doped TiO2 nanotube membrane shows noteworthy enhancement and an efficiency of about 8%.

Atomic layer deposition (ALD) represents a unique deposition technique that allows to coat uniformly var-ious high aspect ratio (HAR) porous nanostructures, in addition to its traditional role to coat flat substrates(e.g. Si wafers). Self-organized anodic TiO2nanotube (TNT) layers belong among the most investigatedinorganic nanostructures. They possess highly functional materials with promising application potentialacross many technological fields. Herein, we review the utilization of ALD for the functionalization ofanodic TNT layers by secondary materials to advance their physicochemical and photoelectrochemicalproperties. First, the application of ALD for functionalization of porous aluminium oxide, which representfundamental HAR nanostructure, is briefly introduced. Then the main experimental parameters govern-ing the uniformity and the conformality of ALD coating within HAR nanostructures are discussed. Finally,the review focuses on the use of ALD to deposit secondary materials into TNT layers for various purposes— the introduction of pioneering studies is followed by particular examples of ALD based functional-izations of coated TNT layers for optimized visible-light absorption, charge separation and passivation,(photo)catalysis, stability, gas sensing, and energy storage. Depozice Atomárních vrstvev (ALD) je unikátní depoziční technika, jenž umožňuje pokrýt rovnoměrně různé porézní nanostruktury s vysokým poměřem stran (tloušťka vs průměr), kromě své tradiční role pro pokrývání rovných substrátů (např. Si waferů). Samoorganizované vrstvy anodických TiO2 nanotrubic (TNT) patří mezi nejstudovanější anorganické nanostruktury. Představují velmi funkční materiál s mnoha aplikačními příležitostmi v různých technologických oborech. V tomto přehledovém článku shrnujeme využití ALD pro funkcionalizaci anodických TNT různými sekundárními materiály s cílem ještě více lepšit jejich celkové fyzikálně-chemické a fotoelektrochemické vlastnosti. V první kapitole popisujeme využití ALD pro funkcinalizaci porezního oxidu hlinitého, což je základní porézní materiál a historicky předchází TNT. V druhé kapitole jsou diskutovány hlavní experimentální parametry techniky ALD, které ovlivňují rovnoměřnost a homogenitu ALD vrstev v jednodimenzionálních strukturách s vysokým poměřem stran. V hlavní části poskytujeme přehled využití různých ALD vrstev na TNT pro různé účely. Po představení pionýrských prací v relevantním oboru uvádíme různé příklady funkcionalizací, které mají zásadní vliv na absorpci viditelného světla do trubic, rozdělění náboje, pasivaci defektů, fotokatalýzu, stabilitu, citlivost na plyny a ukládání energie.