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Self-Improving Na Ion Storage in Oxygen Deficient, Carbon Coated Self-Organized TiO <sub/>2</sub> Nanotubes
摘要： The development of sodium ion batteries is largely motivated by the growing cost and limited resources of lithium. Titanium dioxide (TiO2), in the form of self-organized and well-oriented nanotube arrays, are considered as a highly attractive anode material for sodium ion batteries, due to their inherent safety, low cost and structural stability. This work reports on the sodiation and desodiation characteristics of anodically grown, self-organized TiO2 nanotubes annealed in an Ar/C2H2 atmosphere (TiO2-x-C). It is found that anatase TiO2-x-C nanotubes demonstrate substantial self-improving charge storage capacities as cycling proceeds, leading to a specific capacity of 202.2 ± 50.6 mAh g-1 at a current rate of 30 mA g-1 (C/20). Subsequent kinetic analysis reveals a pseudocapacitive contribution which dominates the Na storage process in TiO2-x-C nanotubes at fast sodiation rates. This pseudocapacitance in TiO2-x-C nanotubes is found to enable exceptional high-rate capabilities with a specific capacity of 58.4 ± 14.6 mAh g-1 at a current rate of 12 A g-1 (20C).
关键词： nanotubes,Na ion,self-improving,batteries,titanium dioxide
更新于2025-09-23 15:21:01
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Strongly Enhancing Photocatalytic Activity of TiO2 Thin Films by Multi-Heterojunction Technique
摘要： The photocatalysts of immobilized TiO2 ?lm suffer from high carrier recombination loss when compared to its powder form. Although the TiO2 with rutile-anatase mixed phases has higher carrier separation ef?ciency than those with pure anatase or rutile phase, the single junction of anatase/rutile cannot avoid the recombination of separated carriers at the interface. In this study, we propose a TiO2/SnO2/Ni multi-heterojunction structure which incorporates both Schottky contact and staggered band alignment to reduce the carrier recombination loss. The low carrier recombination rate of TiO2 ?lm in TiO2/SnO2/Ni multi-heterojunction structure was veri?ed by its low photoluminescence intensity. The faster degradation of methylene blue for TiO2/SnO2/Ni multi-junctions than for the other fabricated structures, which means that the TiO2 ?lms grown on the SnO2/Ni/Ti coated glass have a much higher photocatalytic activity than those grown on the blank glass, SnO2-coated and Ni/Ti-coated glasses, demonstrated its higher performance of photogenerated carrier separation.
关键词： titanium dioxide,multijunction,thin ?lm,photocatalysis,functional coatings
更新于2025-09-23 15:21:01
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Pure Anatase Phase Titanium Dioxide Films Prepared by Mist Chemical Vapor Deposition
摘要： In this research, pure anatase phase titanium dioxide thin films were successfully fabricated for the first time using the mist chemical vapor deposition method, and optional values for deposition temperature and concentration of titanium tetraisopropoxide were established. It was found that the crystallinity of the titanium dioxide film was significantly improved by increasing the deposition temperature. The best crystallinity of titanium dioxide film was obtained at 400 ?C. It was confirmed that pure anatase phase titanium dioxide films could be obtained using different concentrations of titanium tetraisopropoxide. The lower concentration of titanium tetraisopropoxide produced better crystallinity in the resultant titanium dioxide film. The morphologies of the titanium dioxide thin films were also significantly influenced by the concentration of titanium tetraisopropoxide in the precursor solution.
关键词： titanium dioxide,anatase,thin films,mist chemical vapor deposition,growth control
更新于2025-09-23 15:21:01
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Ordered Mesoporous TiO <sub/>2</sub> Gyroids: Effects of Pore Architecture and Nb-Doping on Photocatalytic Hydrogen Evolution under UV and Visible Irradiation
摘要： Pure and Nb-doped TiO2 photocatalysts with highly ordered alternating gyroid architecture and well-controllable mesopore size of 15 nm via co-assembly of a poly(isoprene)-block-poly(styrene)-block-poly(ethylene oxide) block copolymer are synthesized. A combined effort by electron microscopy, X-ray scattering, photoluminescence, X-ray photoelectron spectroscopy, Raman spectroscopy, and density functional theory simulations reveals that the addition of small amounts of Nb results in the substitution of Ti4+ with isolated Nb5+ species that introduces inter-bandgap states, while at high concentrations, Nb prefers to cluster forming shallow trap states within the conduction band minimum of TiO2. The gyroidal photocatalysts are remarkably active toward hydrogen evolution under UV and visible light due to the open 3D network, where large mesopores ensure efficient pore diffusion and high photon harvesting. The gyroids yield unprecedented high evolution rates beyond 1000 μmol h?1 (per 10 mg catalyst), outperforming even the benchmark P25-TiO2 more than fivefold. Under UV light, the Nb-doping reduces the activity due to the introduction of charge recombination centers, while the activity in the visible triple upon incorporation is owed to a more efficient absorption due to inter-bandgap states. This unique pore architecture may further offer hitherto undiscovered optical benefits to photocatalysis, related to chiral and metamaterial-like behavior, which will stimulate further studies focusing on novel light–matter interactions.
关键词： photocatalysis,block copolymers,titanium dioxide,self-assembly
更新于2025-09-23 15:21:01
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Synthesis of “lotus root”-like mesoporous titanium dioxide and its effects on UV response to aconitine release
摘要： Mesoporous titanium dioxide with a “lotus root”-like structure was synthesized for the first time using an improved template-free method. The structure has a BET (Brunauer Emmett Teller) surface area of 688.11 m2/g, a pore volume of 0.743 cm3/g, and a pore size of 3.59 nm. Aconitine, a botanical insecticide, could be loaded onto the mesoporous titanium dioxide via simply soaking the structure and had a maximum loading of 17.6 %. UV spectroscopy was utilized to explore the drug release behaviors, and the results showed that aconitine-loaded mesoporous titanium dioxide particles UV irradiated could successfully release aconitine with a release rate of 46.24%, which was significantly higher than the samples lacking UV irradiation (36.80%). Meanwhile, the release rate of aconitine (48.94 %) for pH 5.5 was significantly higher than that for pH 7.0 (42.09 %). The results of microcalorimetry revealed that both the enthalpy change (?H) and entropy change (?S) were negative (?H < 0, ?S < 0) for the whole process of aconitine loading onto the “lotus root”-like mesoporous titanium dioxide support. Hydrogen bonding was the driving force for drug loading, and this was also verified using Monte Carlo simulations. These results show that the “lotus root”-like mesoporous titanium dioxide material has some potential applications such as the storage and use of plant pesticides.
关键词： “Lotus root”-like mesoporous titanium dioxide,Monte Carlo simulations,hydrogen bonding,UV-responsed drug release
更新于2025-09-23 15:21:01
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Europium and terbium lanthanide ions co-doping in TiO2 photoanode to synchronously improve light-harvesting and open-circuit voltage for high-efficiency dye-sensitized solar cells
摘要： In this study, we explore the effects on the incorporation of europium (Eu3+) and terbium (Tb3+) rare-earth ions into titanium dioxide (TiO2) photoanodes in dye-sensitized solar cells (DSSCs). X-ray photoelectron spectroscopy (XPS) studies affirm that the Eu3+ ions are arranged at the cationic locales of Ti4+ in the matrix whereas the site inhabitance was remunerated by Tb3+ ions, supporting that the anatase phase stays unaltered without generating any new deformities. Additionally, the Eu3+ ions decidedly changed the conduction band minimum of TiO2, actually, Tb3+ ions contrarily conversion because of various vacant trap states in the band gap. Besides, the photoinduced electron transfer estimations show an efficient interfacial charge transfer for co-doped TiO2 (kET = 3.1 ns) contrasted with the bare TiO2 (2.6 ns). DSSCs based on Eu3+/Tb3+ co-doped TiO2 display higher efficiency (9.11%) than those for the bare TiO2 (7.20%) and the exclusively Eu3+ (8.01%) or Tb3+ (7.10%) doped samples, which is ascribed to the joined impact of a faster electron transportation and longer electron lifetime in the co-doped TiO2 film. This work may open another approach to further improve the performance of DSSCs by Eu3+/Tb3+ co-doping technique, advancing the development of DSSCs toward commercial applications.
关键词： Co-doping process,Europium (Eu3+)/terbium (Tb3+) lanthanide ions,Stability,Photoanodes,DSSCs,Titanium dioxide (TiO2) nanopowders
更新于2025-09-23 15:21:01
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Effects of weathering on the performance of self-cleaning photocatalytic paints
摘要： The use of photocatalytic products for the surface coating of buildings is spreading more and more, because of the reduction of atmospheric pollutants and the colour maintenance of the paints over time with reduction of the maintenance costs and the improvement of the aesthetic appearance. The study reports the evaluation of the effects of the atmospheric conditions on three commercial photocatalytic paints containing TiO2. In particular tests were carried out by using samples subjected to accelerated aging inside a climate chamber and naturally aged by exposure for two years to the external environment of the city of Palermo (representative of a coastal environment of the Mediterranean basin). The samples were characterized by Scanning Electron Microscopy (SEM) and Optical Microscopy to evaluate the surface morphology, and by UV–Vis Spectrophotometry to appreciate the colours changes as a result of aging. X-ray diffraction (XRD), moreover, was used to identify the TiO2 phase and static contact angles were determined to evaluate the surface hydrophilicity. The photocatalytic activity was evaluated under UV and solar light irradiation by degrading 2-propanol, used as a probe molecule and analysed by gas chromatography (GC), which is representative of volatile organic compounds (VOC's). The results indicated colour conservation, increase of the surface hydrophilicity and maintenance of the photocatalytic performances.
关键词： Static contact angle,Titanium dioxide,Photocatalytic paints,VOC'S degradation,Weathering effects
更新于2025-09-23 15:21:01
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Effects of water matrix components on degradation efficiency and pathways of antibiotic metronidazole by UV/TiO2 photocatalysis
摘要： In this study, the effects of water matrix components such as anions (Cl-, SO4 2-, NO3 -, HCO3 -, and H2PO4 -); cations (Ca2+, Mg2+, and Fe3+); natural organic matter (humic acid); and pharmaceutical excipient (glucose) on the photocatalytic degradation of metronidazole (MNZ) by UV/TiO2 were investigated. Degradation of MNZ noticeably decreased in the presence of H2PO4 -, Fe3+, and humic acid (HA). However, the addition of glucose tripled the rate of MNZ degradation. The transformation products formed during photocatalysis were detected and identified using Waters UPLC-QTof/MS (ultra-performance liquid chromatography–quadrupole time-of-flight mass spectrometry) and UPLC-MS/MS (ultra-performance liquid chromatography–tandem mass spectrometry) instruments. The enhanced degradation of MNZ in the presence of glucose was due to the side reactions of MNZ and its intermediates with other organics released when glucose was degraded. HA could activate charge transfer steps, resulting in different photodegradation products. Iron(III) ions competed with MNZ under light adsorption and reacted with organic intermediates, which hindered MNZ degradation. The presence of H2PO4 - ions seemed to have no effect on the degradation pathways of MNZ but only slowed down the removal of MNZ and its intermediates by interacting with TiO2. These results indicate that the presence of water matrix components significantly changed the degradation pathways and hence affected the degradation efficiency.
关键词： Photocatalysis,Metronidazole,Titanium dioxide,Water matrix components,Degradation pathways
更新于2025-09-23 15:21:01
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Effect of DI Water Content on the Growth of Anatase TiO<sub>2</sub> Nanotubes Synthesized by Anodization Process
摘要： Vertically aligned anatase TiO2 nanotubes (NTs) were fabricated by anodization of a pure Ti foil in ethylene glycol solutions containing different concentrations of deionized (DI) water. The morphology, elemental composition, and crystallization of TiO2 nanostructures were analyzed by field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray spectroscopy (XPS), respectively. The diameter and length of TiO2 NTs were controlled by varying concentrations of DI water. Furthermore, we found that TiO2 NTs in DI water 12 wt. % was suitable for further applications in UV photodetector due to it has a high volume to surface area ratio and long tube. TiO2 NTs have a high potential in various applications such as UV photodetectors, gas sensor, dye sensitized solar cells, and photocatalysts.
关键词： Anatase TiO2,Anodization,Thermal annealing,Titanium dioxide,Nanotubes
更新于2025-09-23 15:21:01
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Facile, rapid, one-pot synthesis of hydrogenated TiO2 by using an atmospheric-pressure plasma jet submerged in solution
摘要： We report a simple method for the synthesis of hydrogenated TiO2 (H-TiO2) by submerging an atmospheric-pressure plasma jet in a titanium precursor solution. The synthesized H-TiO2 demonstrates improved visible light absorption and electrical conductivity due to a decreased work function and narrowed band gap. Our plasma system has significant benefits compared to previously reported hydrogenation methods. It offers a facile, one-pot synthesis process, rapid synthesis time, and ease of mass production. We expect the plasma system to be a promising technology for the synthesis of H-TiO2, and believe this method has potential for use in new environmental and optoelectronic applications.
关键词： Synthesis,Titanium dioxide,Plasma,Band gap,Hydrogenation
更新于2025-09-23 15:21:01