TiO2 Nanowires Research Articles

Effect of SnO2 Coating on the Structural, Optical, and Electrical Properties of TiO2 Nanowires Fabricated by a Two-Step Deposition Method

Effect of SnO2 Coating on the Structural, Optical, and Electrical Properties of TiO2 Nanowires Fabricated by a Two-Step Deposition Method

Piezoelectric Heterojunctions as Bacteria-Killing Bone-Regenerative Implants.

Heterojunctions are widely used in energy conversion, environmental remediation, and photodetection, but have not been fully explored in regenerative medicine. In particular, piezoelectric heterojunctions have never been examined in tissue regeneration. Here the development of piezoelectric heterojunctions is shown to promote bone regeneration while eradicating pathogenic bacteria through light-cellular force-electric coupling. Specifically, an array of heterojunctions (TiO2/Bi2WO6), made of piezoelectric nanocrystals (Bi2WO6) decorating TiO2 nanowires, is fabricated as a biocompatible implant. Upon exposure to near-infrared light, the piezoelectric heterojunctions generate reactive oxygen species and heat to kill bacteria through photodynamic and photothermal therapy, respectively. Meanwhile, the mechanical forces of the stem cells grown on the implant trigger the heterojunctions to produce electric fields that further promote osteogenesis to achieve osteointegration. The heterojunctions effectively suppress postoperative recurrent infections while promoting osseointegration through the local electric fields induced by cells. Therefore, the piezoelectric heterojunctions represent a promising antibacterial tissue-regenerative implant.

Modelling and optimization of amoxicillin degradation over ZnO and glucose oxidase modified TiO2 nanowire

AbstractRecently, antibiotics posing threats to health and the environment have been highlighted. According to previous reports, amoxicillin is the most hazardous antibiotic in Tehran. In order to overcome the risks associated with the storage and contamination of oxidizing agents, a Janus structure of Ti/TiO2/FA/GOx/ZnO is introduced for in situ steady generation and consumption of H2O2. The most efficient nanowire structure of TiO2 is achieved at 140°C and 4.5 h. The footprints of GOx as the bioactive site to produce H2O2 and ZnO as the photoactive site to dope TiO2 have been proved by Raman, Fourier transform infrared (FTIR), X‐ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses. For the first time, a Minimum Run Resolution V screening has been implemented for seven factors in an amoxicillin degradation process by the so‐called bio‐photo‐catalyst. According to analysis of variance (ANOVA), the significance of the three most important variables is as follows: amoxicillin concentration (C) > the area covered by TiO2 nanowires (E) > ZnO/GOx (F) ratio. The significance of the model over the 95% confidence interval is confirmed by R2 of 0.9970, F‐value of 108.10.

Hydrothermally Synthesized TiO2 Nanowires and Potential Application in Catalytic Degradation of p-Nitrophenol

Hydrothermally Synthesized TiO2 Nanowires and Potential Application in Catalytic Degradation of p-Nitrophenol

Suppressed recombination of a flexible TiO2 nanowires photoanode by coupling of plasmonic Ag nanoparticles in the photoelectrochemical ultraviolet photodetector

The noble metal nanoparticles can improve the efficiency of photoelectric conversion via enhancement of light harvesting for the localized surface plasmon resonance (LSPR) effect. Here, TiO2 nanowires were constructed on carbon fiber cloth as a flexible photoanode for photoelectrochemical (PEC) ultraviolet (UV) photodetector. By decorated noble metal Ag nanoparticles on TiO2 nanowires, the photocurrent was improved from 35.9 μA cm−2 to 268.4 μA cm−2, and the rise and decay time were increased by 0.14 s and 0.12 s, respectively. Moreover, the recombination of photon-generated electrons and holes was also decreased in photoanode due to the Schottky barrier between Ag and TiO2. This work provided an approach to promote the performances of the PEC UV photodetector.

Biphase TiO2\\Zn-tetracarboxy-phthalocyanine twin S-scheme heterojunction nanowires with efficient charge transfer and CO2 photocatalytic conversion

Constructing heterojunction photocatalysts with proper charge transfer channels has been confirmed to be a promising strategy for CO2 photoreduction into chemical fuels. However, promoting photoinduced charge separation in traditional heterojunction catalysts still remains a big obstacle for practical applications. In this work, the TiO2(B)-Anatase\\ZnTcPc twin S-scheme heterojunctions are designed and constructed by loading Zn (II) tetracarboxy phthalocyanine (ZnTcPc) on the prepared TiO2(B)-Anatase biphase TiO2 nanowires by self-assemble strategy. The TiO2(B)-Anatase\\ZnTcPc twin S-scheme heterojunctions effectively promote charge transport across the multi-heterointerfaces and enhance visible light absorption and CO2 adsorption. Thus the optimized hybrid photocatalyst exhibits a remarkable photocatalytic CO2 reduction performance, and the CO yield reaches 237.8μmol g−1h−1. The CO2 photoreduction mechanism and charge transfer properties in the twin S-scheme heterojunction are also investigated and characterized. This research offers a viable approach to enhancing the heterojunction system for excellent photocatalytic performance.

Hydrothermal synthesis of bare TiO2 nanowires and polystyrene (PS)-TiO2 nanowires used for selective photocatalytic oxidation of 3-pyridinemethanol in water and PS photodegradation in solid state

In the present work, nanowire (NW) structured TiO2 nanoparticles were prepared using the hydrothermal method and characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and BET specific surface area techniques. They were obtained in the anatase phase and presented a high surface area (ca. 300 m2/g). A commercial TiO2 (anatase, Merck) was used for comparison. The TiO2 catalysts were tested for photocatalytic oxidation of 3-pyridinemethanol to 3-pyridinemethanal and vitamin B3 in water under UVA irradiation. The effects of acid treatment and subsequent calcination for TiO2 catalysts after the hydrothermal synthesis were also investigated. The sample, subjected to acid treatment and calcined at 300 °C (NW-HCl-300), showed the highest photocatalytic activity and selectivity towards the products. Consequently, this sample and Merck TiO2 were used to prepare polystyrene (PS)/TiO2 composites using the hydrothermal method. They were characterized by XRD, SEM–EDX, Nuclear Magnetic Resonance (NMR), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), UV–Vis, Gel Permeation Chromatography (GPC), and contact angle measurements and tested for PS (present in the composite) photodegradation. The results indicated that NW-HCl-300 had a high surface area, and was highly hydroxylated, favouring a good distribution of PS in the composite. The composite presented high thermal stability, but under UVA irradiation the polymer underwent solid-state photocatalytic degradation due to the contact with TiO2. The composite photodegradation was investigated using gravimetric, GPC, FT-IR, UV–Vis, and SEM techniques.

Porous titanium nitride nanowire array on carbon fiber for the applications in fiber-shaped solar cell and lithium-ion battery

Porous titanium nitride nanowires were fabricated on carbon fibers (CFs) by growing a TiO2 nanowires array on CFs and subsequent ammonification (TiN-CF). This design combined the high electrical conductivity of CF with the superior electrocatalytic activity of TiN to construct a fast electron-transport passage and highly active sites along the electron pathway. Benefiting from both its construction advantages and high flexibility, TiN-CF could be effectively utilized in fiber-shaped dye-sensitized solar cells (FDSSCs) and fiber-shaped lithium-ion battery (FLIB). For the FDSSCs, TiN-CF had been demonstrated to function as low-cost and excellent counter electrodes (CEs) with a desirable photoelectric conversion efficiency of 6.48 %, comparable to or even surpassing that of a Pt wire CE at 6.36 %. When used as the anode for FLIB, TiN-CF exhibited favorable electrochemical properties including a good initial discharge capacity of 556.6 mAh g−1 at rates of 0.2C, a high rate capability of 493.5 and 272.2 mAh g−1 at 1C and 10C respectively, as well as superior cyclic stability with a capacity retention of 420.5 mAh g−1 after 300 cycles at 2C. This work also provides valuable insights for future development and rational design in fiber-shaped electronic devices.

Enhanced dye-sensitized solar cell performance using Ag nanoparticle-decorated TiO2 nanowire photoanode using the GLAD technique

Enhanced dye-sensitized solar cell performance using Ag nanoparticle-decorated TiO2 nanowire photoanode using the GLAD technique

Influence of the Structure of Hydrothermal-Synthesized TiO2 Nanowires Formed by Annealing on the Photocatalytic Reduction of CO2 in H2O Vapor.

The present study investigates the photocatalytic properties of hydrothermally synthesized TiO2 nanowires (NWs) for CO2 reduction in H2O vapor. It has been demonstrated that TiO2 NWs, thermally treated at 500-700 °C, demonstrate an almost tenfold higher yield of products compared to the known commercial powder TiO2 P25. It has been found that the best material is a combination of anatase, TiO2-B and rutile. The product yield increases with increasing heat treatment temperature of TiO2 NWs. This is associated with an increase in the degree of crystallinity of the material. It is shown that the best product yield of the CO2 reduction in H2O vapor is achieved when the TiO2 NW photocatalyst is heated to 100 °C.

Controlled Assembly of Nanowires into Welded Nanowire Networks for Memristor Device Fabrication

Next-generation electronic devices are essential for neuromorphic computing (or brain-inspired computing), which is essential for the high-speed processing of big data using artificial intelligence tools.(1) Memristors, an important constituent of these next-generation electronic devices, have been fabricated using many forms of metal oxides, including nanowires. Nanowires forms of oxides, although reduce the complexity of the memristive device fabrication process, need many technological advances for their widespread use in memristor fabrication.(1) For instance, the cyclability of devices needs to be improved. Furthermore, realizing the high density of nanowire-based memristor devices requires methods for addressing individual nanowires in large assemblies (i.e., arrays) of nanowires, strategies for which also need to be developed.(1) A possible avenue to address these problems is through the use of nanowire networks,(1) specifically those that have nanowires welded together via bridges that have the same chemical composition as those of the nanowires themselves.(2) In this configuration, the resistive switching of both the nanowires and the randomly-formed junctions between the nanowires can be employed to make mesoscale devices, circumventing the need to individually address each nanowire in the nanowire assemblies.(1) Realizing memristive devices based on welded nanowire networks, therefore, requires a strategy for assembly via welding of pre-synthesized nanowires into networks that offer the ability to control the chemical compositions of the interfaces between the nanowires and the densities of nanowires within the assemblies.(2, 3) In the presentation, strategies developed by our group for the assembly of semiconductor nanowires into welded nanowire networks of controlled densities will be discussed in detail. Specific devices that will be discussed include assembly via welding of Mg2Si, TiO2 and TiC nanowires.(2, 3) The assembly via welding of nanowires into networks is expected to accelerate the testing of mesoscale memristive devices, irrespective of the method employed for the synthesis of the nanowires used in the assemblies. This is expected to aid in accelerating both the science and technology needed for the deployment of memristive devices.

Pengembangan TiO2 nanowire terdoping Nikel Kobalt sebagai Fotokatalis yang Efisien untuk Menghilangkan Pewarna Tartrazine

Tartrazine is a yellow synthetic dye that is widely used as a coloring agent in food and beverage products. However, the safety of this chemical compound is still a concern due to potential health risks such as allergic reactions, hyperactive behavior in children, increased risk of cancer and other negative impacts. This research aim to introduces a new approach to reduce the concentration of tartrazine dye using cobalt and nickel doped TiO2 nanowires. Cobalt- and nickel-doped TiO2 nanowires were synthesized by a hydrothermal method, followed by thermal treatment at 270°C, and then used in a photocatalytic reactor using UV irradiation to facilitate the reduction of tartrazine concentration. Material characterization was carried out to determine the morphology and crystallinity of the photocatalyst which is effective in reducing the absorption of tartrazine solution. The photocatalytic degradation experiment demonstrates the ability of the synthesized material as a photocatalyst, effectively reducing the absorbance of tartrazine solution, a commonly used food coloring. This finding promises significant progress in the development of sustainable food safety strategies by offering a dye degradation method.

Fluorogenic Reaction Probes Defect Sites on Titanium Dioxide Nanoparticles

AbstractTitanium dioxide nanoparticles (TiO2 NPs) have traditionally been utilized as industrial catalysts, finding widespread application in various chemical processes due to their exceptional stability and minimal toxicity. However, quantitatively assessing the reactive sites on TiO2 NPs remains a challenge. In this study, we employed a fluorogenic reaction to probe the apparent reactivity of TiO2 NPs. By manipulating the number of defect sites through control of hydrolysis speed and annealing temperature, we determined that the Ti(III) content is positively correlated with the reactivity of TiO2 NPs. Additionally, these Ti(III) sites could be introduced by reducing commercial TiO2 NPs using NaBH4. Our findings suggest that fluorogenic oxidation of Amplex Red is an effective method for probing defect site densities on TiO2 NPs. Utilizing single‐molecule fluorescence imaging, we demonstrated the ability to map defect site density within TiO2 nanowires. Achieving sub‐nanoparticle spatial resolution, we observed significant intraparticle and interparticle variations in the defect site distribution, leading to substantial reactivity heterogeneity.

Nano-Sized rGO-Encapsulated TiO2 Nanowire-Filled PDMS cone type dielectric elastomer actuator operating at low applied electric field

Dielectric elastomer actuators (DEAs) have versatile applications in soft robotics, medical devices, and environmental monitoring, making them a highly anticipated area for future applications. On the other hand, developing DEAs exhibiting high strain at low voltages remains challenging. This paper reports a strategy for enhancing the actuating performance of polydimethylsiloxane (PDMS) at low voltages by preparing a hybrid filler comprised of TiO2 nanowires (TiO2 NWs), polydopamine (PDA), and nano-sized reduced graphene oxide (nrGO). This hybrid filler, merging the virtues of these three materials, was added at 15 parts per hundred of rubber (phr), resulting in a 2.3-fold increase in the dielectric permittivity of PDMS while mitigating the increase in loss tangent and enhancing efficiency. Actuators fabricated using this composite exhibited the highest deformation at 10 phr, reaching approximately 27.31 % (at 28 V/µm), representing a remarkable 15.2-fold improvement compared to pure PDMS. Moreover, even at a low voltage of 1.6 V/µm, they displayed a substantial actuated strain of 2 %. This novel strategy for manufacturing hybrid fillers is a promising example of enhancing the performance of DEAs, offering innovative solutions for future technological advancements.

Hybrid 1D titanium oxide nanowire – Reduced graphene oxide nanocomposites as efficient catalyst support for PEMFC

With hydrogen being projected as the fuel of the future, proton exchange membrane fuel cells (PEMFC) have regained prominence as a zero-emission power source. Researchers are focusing on replacing the conventional carbon support used for the platinum catalysts with alternative materials to improve the durability of the electrocatalysts. Despite being a potential candidate, graphene-based materials have been limited by their lower limiting current density, possibly due to restacking of the graphene sheets. On this note, we introduced varying quantities of metal-oxide based 1D TiO2 nanowires to reduced graphene oxide (rGO) support and analysed their impact on the performance of the electrocatalyst. The optimized support with an initial content of 60 wt.% GO and 40 wt.% TiO2 exhibited higher mass transfer limiting current density, after Pt incorporation (Pt/TiO2-rGO), in comparison to the other composites. The catalyst showed higher retention in electrochemical surface area (1.42 times) and mass activity (1.48 times) compared to the commercial Pt/C after an accelerated durability test. Polarization studies carried out in a 25 cm2 fuel cell fixture exhibited a peak power density close to 720 mW cm−2 and almost two times higher current density (at 0.6 V) than the catalyst without TiO2. These results reaffirm the role of TiO2 in overcoming the limitations of graphene-based support.

Photoelectrochemical properties of doped TiO2 nanowires grown by seed-assisted thermal oxidation

Titanium dioxide Nanowires (NWs) are particularly interesting because of their very high surface/volume ratio and their photocatalytic activity allows them to be used in a myriad of applications. This manuscript presents a study of nanowires grown on a conductive substrate making use of a seed-assisted thermal oxidation process. To obtain doped NWs, before the oxidation, metallic titanium was doped with Fe (or Cr) by ion implantation technology. Analyses showed good quality Rutile phase and light absorption in the visible range. Transport properties of the NWs/electrolyte junction were investigated by using linear sweep voltammetry and electrochemical impedance spectroscopy. They allowed us to measure the photovoltage and the barrier height of the junction. We also evaluated the density of hole trap states at the interface during illumination. Electrical results indicate that the formation of deep levels, induced by doping, influences the electron concentration in the TiO2 and the transport properties.Graphical abstract

Activity, stability, and kinetic study of CuO/TiO2 Janus photocatalyst for rhodamine B degradation

ABSTRACT The CuO/TiO2 photocatalyst was synthesized using hydrothermal and sonochemical methods and subsequently applied to degrade rhodamine B in wastewater. The best synthesis conditions were established, determining Cu(NO3)2 solution concentration of 2.5 wt.% and calcination temperature of 500 °C. The CuO/TiO2 photocatalyst underwent characterization through various techniques, including inductively coupled plasma spectroscopy (ICP), photoluminescence, X-ray diffraction, ASAP, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy. TEM and SEM analyses revealed the presence of TiO2 nanowires and CuO nanoparticles. The Box–Behnken design, encompassing 27 experimental runs, assessed the impact of process variables such as initial dye concentration, pH, UV lamp power, and catalyst dose on the degradation process. The model's R2 value of 0.9893 indicated a high precision in fitting the predicted data to their actual values. Analysis of variance results highlighted UV irradiation power as the most significant variable within the design space. In addition, the CuO/TiO2 photocatalyst demonstrated efficacy under visible light irradiation. Light-expanded clay aggregate beads were chosen as the substrate for photocatalyst immobilization, which enhanced the reaction rate. The stability of CuO/TiO2 was evidenced by about 2% reduction in efficiency after four degradation cycles.

Silver-infused TiO2 nanowires and unveiling their potential for superior wastewater dye remediations.

Silver infused ultrathin TiO2 nanowires (NWs) were synthesized via a single step solvothermal approach. The crystallinity, structure, and morphology were determined to understand the physicochemical nature of the nanocomposites. The catalytic efficiency of the newly synthesized nanocatalysts was tested for the textile waste treatment taking methylene blue (MB) as model pollutant under solar light irradiations. Nearly 96% photodegradation efficiency for MB was achieved within 20 min. Furthermore, the recyclability of the photocatalyst was also studied, and the material remained stable and effective up to four consecutive runs. RESEARCH HIGHLIGHTS: Precise size-controlled synthesis of Ag-incorporated titania nanowires (ATNWs) Controlled aspect ratios, with tunable lengths and diameters (100-3 nm) via precursor and surfactant optimization Demonstrated ATNWs' efficiency in degrading toxic dye, methylene blue (MB) 96% photodegradation efficiency for MB achieved within 20 min using 3 nm thick annealed TiO2 NWs Recyclability efficiency of photocatalyst, which remained stable and effective for up to four consecutive runs.

A H2O2 Oxidation Approach to Ti3C2/TiO2 for Efficient Photocatalytic Removal of Distinct Organic Pollutants in Water.

To develop versatile photocatalysts for efficient degradation of distinct organic pollutants in water is a continuous pursuit in environment remediation. Herein, we directly oxidize Ti3C2 MXene with hydrogen peroxide to produce C-doped anatase TiO2 nanowires with aggregates maintaining a layered architecture of the MXene. The Ti3C2 MXene provides a titanium source for TiO2, a carbon source for in situ C-doping, and templates for nanowire aggregates. Under UV light illumination, the optimized Ti3C2/TiO2 exhibits a reaction rate constant 1.5 times that of the benchmark P25 TiO2 nanoparticles, toward photocatalytic degradations of trace phenol in water. The mechanism study suggests that photogenerated holes play key roles on the phenol degradation, either directly oxidizing phenol molecules or in an indirect way through oxidizing first the surface hydroxyl groups. The unreacted Ti3C2 MXene, although with trace amounts, is supposed to facilitate electron transfer, which inhibits charge recombination. The unique nanostructure of layered aggregates of nanowires, abundant surface oxygen vacancies arising from the carbon doping, and probably the Ti3C2/TiO2 heterojunction guarantee the high photocatalytic efficiency toward removals of organic pollutants in water. The photocatalyst also exhibits an activity superior to, or at least comparable to, the benchmark P25 TiO2 toward photodegradations for typical persistent organic pollutants of phenol, dye molecule of rhodamine B, antibiotic of tetracycline, pharmaceutical wastewater of ofloxacin, and pesticide of N,N-dimethylformamide, when evaluated in total organic carbon removal.

Au modified TiO2 nanowires prepared by photodeposition for selective and efficient electrochemical reduction of CO2

Electrocatalytic CO2 reduction (CO2ER) to produce formic acid (HCOOH) would be an attractive means for carbon neutralization. In order to realize efficient CO2ER and economical conversion of CO2, the applying of metal active sites on surface of semiconductor has emerged as a promising strategy. Herein, we report the preparation of alkaline modified TiO2 nanowires (NWs) as the substrate for Au photodeposition. The as-fabricated Au/TiO2 NWs exhibits high activity and selectivity towards HCOOH production compared with traditional catalysts. The key factors including deposition time, solution, and etc. And their effects on CO2ER performance have been systematically investigated. At −0.8 V vs RHE, the Faraday efficiency of the HCOOH can reach to 86.49 %, while the current density is 15.94 mA cm−2. In addition, Au/TiO2 NWs also exhibited good stability after 18 h electrocatalytic CO2RR under the voltage of −0.8 V vs RHE. Electrochemical tests indicated that Au/TiO2 NWs process favorable intrinsic electrochemical properties, high ESCA and accelerating charge transfer process make Au/TiO2 NWs obtain abundant active sites and kinetically favorable. This work provides a convenient fabrication strategy of Au/TiO2 based catalyst, which can guide the design and modification of gold for CO2ER into formic acid.