TiO2 Fibers Research Articles

Synergistic Manipulation of Zn2+ Ion Flux and Nucleation Induction Effect Enabled by 3D Hollow SiO2/TiO2/Carbon Fiber for Long‐Lifespan and Dendrite‐Free Zn–Metal Composite Anodes

AbstractAqueous rechargeable zinc–metal batteries are a promising candidate for next‐generation energy storage devices due to their intrinsic high capacity, low cost, and high safety. However, uncontrollable dendrite formation is a serious problem, resulting in limited lifespan and poor coulombic efficiency of zinc–metal anodes. To address these issues, a 3D porous hollow fiber scaffold with well‐dispersed TiO2, SiO2, and carbon is used as superzincophilic host materials for zinc anodes. The amorphous TiO2 and SiO2 allow for controllable nucleation and deposition of metal Zn inside the porous hollow fiber even at ultrahigh current densities. Furthermore, the as‐fabricated interconnected conductive hollow SiO2 and TiO2 fiber (HSTF) possess high porosity, high conductivity, and fast ion transport. Meanwhile, the HSTF exhibits remarkable mechanical strength to sustain massive Zn loading during repeated cycles of plating/stripping. The HSTF with interconnected conductive network can build a uniform electric field, redistributing the Zn2+ ion flux and resulting in smooth and stable Zn deposition. As a result, in symmetrical cells, the Zn@HSTF electrode delivers a long cycle life of over 2000 cycles at 20 mA cm−2 with low overpotential (≈160 mV). The excellent cycling lifespan and low polarization are also realized in Zn@HSTF//MnO2 full cells.

TiO2 nanofibers fabricated by electrospinning technique and degradation of MO dye under UV light

Abstract Titanium dioxide (TiO2) nanofibers were synthesized by electrospinning to optimize the photocatalytic action efficiency. The synthesis of the fibers was carried out at four different wt% concentrations: 8, 9, 10 & 11% of polymer polyvinylpyrrolidone (PVP). The TiO2 fibers were further calcined at 700 °C to get powder form. The uncalcinated and calcined TiO2 nanofibers were characterized by using X-Ray diffraction (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and UV-Visible spectroscopy. Raman spectroscopy confirmed the rutile phase of the calcined TiO2nanofibers in powder form with a crystallite size of 34–38 nm. The surface morphology of the uncalcinated and calcined TiO2 nanofibers was examined by SEM and the fiber diameter found to be 360–540 nm. The optical bandgap of the calcined TiO2 nanofibers was found in the range of 3.29–3.24 eV. The photocatalytic activity of the TiO2 nanofibers as examined for uncalcinated and calcined nanofibers, methyl orange (MO) dye degraded up to 98 and 78%, respectively in 180 min under the exposure of UV light. Uncalcinated TiO2 nanofibers were found more suitable for degradation of MO dye as compared to calcined nanofibers.

Interfacial active-site-rich 0D Co3O4/1D TiO2 p-n heterojunction for enhanced photocatalytic hydrogen evolution

The hydrogen evolution activity of photocatalysts could be optimized by improving charge separation, light absorption capacity, and surface-active site number. In an attempt to engineer these critical factors in semiconductor photocatalytic processes, herein, we construct an active-site-rich 0D/1D Co3O4/TiO2 p-n heterojunction by growing p-type Co3O4 nanoparticles onto the surface of n-type TiO2 porous fibers. The in situ-generated porous outer walls formed over the surface of TiO2 fibers can increase the accessible active sites and enhance the light capture capacity. The optimal 0D/1D Co3O4/TiO2 heterojunction exhibits the excellent H2 evolving rate of 3.46 mmol g−1h−1 and considerably higher stability than its counterparts, including TiO2 fibers, 2D/1D and 3D/1D Co3O4/TiO2 hybrids. The main reason for this eminent photocatalytic performance was due to the synergistic effect of the porous outer-walls of the TiO2 nanofibers, favourable intimate interface between Co3O4 and TiO2, built-in electric field induded by p–n heterojunction and the cocatalytic effect of Co3O4, which can create more active sites and lead to rapid charge carrier migration. This study provides an important guideline for designing surface-engineered heterostructures in photocatalytic applications.

Dispersion of Natural Airborne TiO2 Fibres in Excavation Activity as a Potential Environmental and Human Health Risk.

Titanium is the ninth most abundant element, approximately 0.7% of the Earth crust. It is used worldwide in large quantities for various applications. The IARC includes TiO2 in Group 2B as possibly carcinogenic to humans suggesting that pathological effects correlate to particle size and shape. This study case quantifies the release of natural TiO2 particles during mining activity, involving meta-basalt and shale lithologies in the Ligurian Alps, during excavation of the Terzo Valico as part of the Trans-European Transport Network. Type, width, length, aspect ratio, and concentration of TiO2 particles in needle habit were determined. The different samplings have reported that airborne concentrations in meta-basalt were 4.21 ff/L and 23.94 ff/L in shale. In both cases, the concentration never exceeds the limits established by various organizations for workers health protection. Nevertheless, TiO2 elongated particles, recognized as rutile, showed the dimensional characteristic of fibres, as reported by WHO. These fibres deserve particular attention because they can reach the alveolar space and trigger inflammation and chronic diseases. The results indicate that monitoring the TiO2 in both working environments and Ti-rich geological formations, associated with epidemiological studies, may represent a useful tool to determine the exposure risk of workers and the general population.

Photocatalytic Activity of Fibrous Ti/Ce Oxides Obtained by Hydrothermal Impregnation of Short Flax Fibers.

Fibrous Ti/Ce oxide photocatalysts were prepared for the first time by a biomimetic solution process using short flax fibers (flax straw processing waste) as a biotemplate. Titanium polyhydroxy complex solutions with 3% and 5% cerium were used as precursors. Flax fibers were impregnated in an autoclave under hydrothermal conditions. Ti/Ce oxides were obtained from the biotemplate by annealing at 600 °C. The photocatalytic activity of the Ti/Ce oxides was studied by the adsorption and decomposition of the dye rhodamine B under UV irradiation. The photocatalytic decomposition of the dye was 50% and 75% faster for Ti/Ce oxides with 3% and 5% Ce, respectively, than for the analogous undoped fibrous TiO2. The morphologies, textures, and structures of the photocatalysts were studied by scanning electron microscopy, low temperature N2 adsorption/desorption, UV-Vis spectroscopy, and X-ray and XPS analytical methods. It was shown that the introduction of Ce into the precursor solution increased the surface irregularity of the Ti/Ce oxide crystallites compared to pure TiO2. This effect scaled with the Ce concentration. Ce improved the UV light absorption of the material. The Ti/Ce oxides contained Ce4+/Ce3+ pairs that played an important role in redox processes and intensified the photocatalytic activity.

Tunnel elasticity enhancement effect of 3D submicron ceramics (Al2O3, TiO2, ZrO2) fiber on polydimethylsiloxane (PDMS)

Some polymers are flexible, foldable, and wearable. Structural—functional composite is fabricated by adding inorganic fillers with functional properties. Up to date, compared with the polymer matrix, the composite prepared by polymer-inorganic fillers has lower flexibility, higher brittleness, and higher modulus of elasticity. In this paper, three-dimensional (3D) net-shaped submicron α-Al2O3, orthorhombic ZrO2, and rutile TiO2 fiber were fabricated by solution blowing spinning on a large scale. On the contrary, the elastic modulus (E) of the composite prepared by this 3D ceramic fiber was greatly reduced, and the flexibility of the composite was higher than that of the polymer matrix. When the strain was 75%, the E of the 3D net-shaped Al2O3 fiber-polydimethylsiloxane (PDMS) composite was 20% lower than that of PDMS. When the strain was 78%, the E of the 3D net-shaped TiO2 fiber-PDMS and 3D net-shaped ZrO2 fiber-PDMS composites decreased by 20% and 25%, respectively. This abnormal effect, namely the tunnel elastic enhancement effect, has great practical significance. In all-solid-state lithium-ion batteries, the composite inhibits lithium dendrite growth and the 3D inorganic network contributes to lithium ion transport. It is possible to promote the industrial production of low-cost and large-scale flexible solid-state lithium-ion batteries and it can enhance the energy storage density of energy storage materials. This novel idea also has bright prospects in flexible electronic materials.

Rational design of Z-scheme Bi12O17Cl2/plasmonic Ag/anoxic TiO2 composites for efficient visible light photocatalysis

An all-solid-state Z-scheme plasmonic Ag-Bi12O17Cl2/TiO2 heterojunction, for the first time, was constructed. The in-situ one-step preparation of Bi12O17Cl2 in the presence of Cl source on the surface of TiO2 fiber, which has not been previously reported, led to the successful coupling Bi12O17Cl2 and TiO2. The Ag particles were selectively anchored on the surface of Bi12O17Cl2 and the interface of Bi12O17Cl2/TiO2. The plasmonic effect and electron-hole bridge at the interfaces were thus separately realized. The Ag-Bi12O17Cl2/TiO2 exhibited greatly increased reaction rate in the removal of azo dye molecules under visible light irradiation, which was 5.4 and 1.4 times higher than that of TiO2 and Bi12O17Cl2, respectively. The enhanced photocatalytic performance was ascribed to the increased specific surface area, formed Z-scheme heterojunction, and the plasmonic effect of Ag nanoparticles. This work paves a new way for the rational design of recyclable, efficient Z-scheme photocatalyst for environmental remediation.

Electrospun-based TiO2 nanofibers for organic pollutant photodegradation: a comprehensive review

Abstract Titanium dioxide (TiO2) is commonly used as a photocatalyst in the removal of organic pollutants. However, weaknesses of TiO2 such as fast charge recombination and low visible light usage limit its industrial application. Furthermore, photocatalysts that are lost during the treatment of pollutants create the problem of secondary pollutants. Electrospun-based TiO2 fiber is a promising alternative to immobilize TiO2 and to improve its performance in photodegradation. Some strategies have been employed in fabricating the photocatalytic fibers by producing hollow fibers, porous fibers, composite TiO2 with magnetic materials, graphene oxide, as well as doping TiO2 with metal. The modification of TiO2 can improve the absorption of TiO2 to the visible light area, act as an electron acceptor, provide large surface area, and promote the phase transformation of TiO2. The improvement of TiO2 properties can enhance carrier transfer rate which reduces the recombination and promotes the generation of radicals that potentially degrade organic pollutants. The recyclability of fibers, calcination effect, photocatalytic reactors used, operation parameters involved in photodegradation as well as the commercialization potential of TiO2 fibers are also discussed in this review.

Electrospun TiO2 nanofibers for water and wastewater treatment: a review

Water and wastewater treatment is a global challenge that requires innovative solutions. Electrospinning is a versatile and simple technique that allows the generation of ultrathin fibers of numerous compositions. Titanium dioxide is a photocatalyst with applications in several technological fields. Thus, the use of electrospinning to produce TiO2 nanofibers is an approach that may bring new insights for the treatment of contaminated water. In this review, it is aimed to provide a comprehensive overview of electrospinning technique and electrospun TiO2 nanofibers production, as well as their application in water and wastewater treatment. First, it is provided a brief introduction to the development of electrospinning-related processes, followed by a discussion of its principle, apparatus, methods and materials commonly used. In the sequence, it is presented the current and potential methods for electrospun TiO2 nanofibers and some aspects related to experimental conditions, catalysts immobilization, metal and nonmetal doping, characterization techniques and applications. The effects of processing parameters on properties as catalyst band gap, adsorption capacity and catalytic efficiency are also discussed. Afterward, the application of electrospun TiO2 nanofibers for pollutants removal from water through photodegradation is highlighted by focusing on some representative examples. Finally, the perspectives are presented regarding challenges, opportunities, and new directions for the application of electrospun TiO2 fibers.

Electrospun Ti-doped haematite fibres and their properties

Electrospun Ti-doped α-Fe2O3 fibres were synthesized and their properties compared with electrospun α-Fe2O3 and TiO2 fibres as reference samples. All samples were characterized with FE SEM (field emission scanning electron microscopy), XRD (X-ray diffraction), 57Fe Mossbauer, FT-IR (Fourier transform infrared) and UV/Vis/NIR (ultraviolet/visible/near infrared) techniques. Ti-doped α-Fe2O3 fibres consisted of the interconnected nanoparticles. These fibres showed a hollow substructure. XRD and 57Fe Mӧssbauer spectroscopy showed the titanium cations to be incorporated up to 10 mol% into the α-Fe2O3 crystal structure. The incorporation of titanium cations into the α-Fe2O3 crystal structure caused changes in the corresponding FT-IR spectra. The band gap values of the electrospun fibres were determined and the photocatalytic degradation of rhodamine B (RhB) with the same fibres was investigated.

Porous TiN/Red Phosphorus Nanocomposite for Photocatalytic Hydrogen Evolution

AbstractThe visible light induced photocatalytic H2 evolution from water with the help of photogenerated electrons in the TiN/red phosphorous (RP) nanocomposite is studied. The porous TiN nanotubes are obtained by nitridation (heat treatment under NH3 flow) process on hydrothermal synthesized TiO2 fibers. The RP is incorporated into the porous TiN nanotubes by heat treatment in the sealed ampules. The porous TiN nanotube provide an effective conducting channel for the photogenerated electrons, which is reflected in the enhanced photocatalytic H2 evolution compared to the pristine RP.

Synthesis and characterization of TiO2 and palm oil fiber ash hybrid photocatalysts for seawater pretreatment

Titanium dioxide (TiO2) has been used in various applications such as air purification, water purification, and photoelectrochemical conversion systems. However, developing advanced materials with enhanced performance for catalytic applications, especially water treatment, is highly required. This work aims to study the effect of (TiO2) photocatalyst in pretreatment seawater desalination. The catalyst with a mass ratio of TiO2: palm oil fibre ash (POFA) at 0:100, 40:60, 60:40, and 100:0 was synthesized via wet impregnation. The catalyst was calcined at 500 ℃ for four hours. The mixture of artificial seawater and catalyst at a mass ratio of photocatalyst: artificial seawater at 1:300 was put in a one-litre borosilicate photo-reactor fixed with mercury light of 350 nm for two hours with stirring at 1000 rpm. In this investigation, an evaporator was used to collect the freshwater. The fresh and spent catalysts were characterized via X-Ray Diffractogram (XRD), Nitrogen physisorption analysis, Diffuse Reflectance Spectrometer (DRS), Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDX). The catalyst with Ti: palm oil fibre ash (POFA) at 40:60 and 60:40 can reduce the COD at 45 % and 41%, respectively. As more OPFA was added into the hybrid TiO2 catalyst, there has been a change in the properties of seawater due to the use of special evaporators, especially EC and TDS. It can be deduced that the hybrid TiO2 photocatalyst synthesized with OPFA has vast potential to treat seawater.

Trimetallic composite nanofibers for antibacterial and photocatalytic dye degradation of mixed dye water.

Membrane technology is an advanced approach to making a healthier and cleaner environment. Using such catalytic membrane technology to get clean, usable water by removal of dye impurities as well as pathogenic microbes is the main goal behind the research work. Here, we present the synthesis and efficacy study of polymethyl methacrylate (PMMA)-based Ag/ZnO/TiO2 trimetallic bifunctional nanofibers with antibacterial and photocatalytic activity. The nanofibers have been proven to be effective for the degradation of methylene blue (MB 93.4%), rhodamine B (Rh 34.6%), auramine-O (Au 65.0%) and fuchsin basic (FB 69.8%) dyes individually within 90 min in daylight. The study is further extended in abating a mixture of these dyes from contaminated water using composite nanofibers. Also, in the case of a mixture of these dyes (3 ppm each), nanofibers show dye degradation efficiency (DDE) of 90.9% (MB), 62.4% (Au) and 90.3% (FB and Rh) in 60 min. The role of Ag nanoparticles with a synergic photocatalytic effect on ZnO and TiO2 is also demonstrated. Also, PMMA/ZnO/TiO2 composite fiber membrane in synergy with silver particles shows better antibacterial activity against Gram-negative bacteria E. coli, making PMMA/Ag/ZnO/TiO2 fibers a promising candidate in water purification.Electronic supplementary materialThe online version of this article (10.1007/s13204-020-01540-6) contains supplementary material, which is available to authorized users.

Dispersive Micro-solid Phase Extraction with Fibrous TiO2@g- C3N4 Nanocomposites Coupled with ICP-MS for the Determination of Cobalt and Nickel in Environmental and Biological Samples

Dispersive Micro-solid Phase Extraction with Fibrous TiO2@g- C3N4 Nanocomposites Coupled with ICP-MS for the Determination of Cobalt and Nickel in Environmental and Biological Samples

Electrospinning synthesis of N-doped TiO2 fiber membranes and its enhanced photocatalysis performance

N-doped TiO2 fiber membranes were prepared by electrospinning method and adsorptive chitosan was added as a nitrogen source. The obtained TiO2 fiber membranes were analyzed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results show that the film has adsorption properties; furthermore, the morphology of the TiO2 fiber with a chitosan content of 0.5 g after calcination provides the best catalytic performance; An anatase–rutile titania was found in the oxidized fiber film found in the Raman spectrum TiO2; XPS demonstrated that the introduction of chitosan could replace N atom with partial lattice oxygen in TiO2. Moreover, the degradation rate of methylene blue of the material was about 60–80% after 4-h reaction, and the maximum degradation rate was achieved by nanofiber film with chitosan concentration of 0.5 g.

Laser-induced nanofibrous titania film electrode: A new approach for energy storage materials

Abstract The research described here proposes a novel use of titanium oxide nanofibrous film as advanced electrode material for high performance supercapacitors. High frequency picosecond laser pulses were employed to generate a film of oxidized Ti on Ti substrate. Physico-chemical characterizations and morphological studies revealed the formation of fibrous TiO2 micro/nano-structures. The electrochemical measurements of the generated nanostructures showed their improved electrochemical properties and proved the feasibility of using laser pulses for fabrication of advanced electrodes with high specific capacitance. Also, our results showed by double laser processing, the average diameter of the generated TiO2 fibers decreased from 300 nm to the range of 60–70 nm. Combination of having higher porosity (smaller fiber diameters) and more oxidized Ti results in better supercapacitance behaviours. These studies demonstrated the usefulness of laser generated nanofibrous film as a novel electrode material for high performance supercapacitors. It can lead to promising methods for fabrication of advanced electrodes with high energy and power density with excellent cyclic stability.

Biomorphic Fibrous TiO2 Photocatalyst Obtained by Hydrothermal Impregnation of Short Flax Fibers with Titanium Polyhydroxocomplexes

A biomimetic solution technology for producing a photocatalytic material in the form of biomorphic titanium oxide fibers with a hierarchical structure using short flax fiber as a biotemplate is proposed. The impregnation of flax fibers intensified under hydrothermal conditions with a precursor was performed in an autoclave to activate the nucleation of the photoactive TiO2 phases. The interaction between precursor and flax fibers was studied by using infrared spectroscopy (IR) and differential scanning calorimetry/thermogravimetry analysis (DSC/TG). The morphology, structure, and textural properties of the TiO2 fibers obtained at annealing temperatures of 500–700 °C were determined by X-ray diffraction analysis, scanning electron microscopy, and nitrogen adsorption/desorption. It is shown that the annealing temperature of the impregnated biotemplates significantly affects the phase composition, crystallite size, and porous structure of TiO2 fiber samples. The photocatalytic activity of the obtained fibrous TiO2 materials was evaluated by using the decomposition of the cationic dye Rhodamine B in an aqueous solution (concentration 12 mg/L) under the influence of ultraviolet radiation (UV). The maximum photodegradation efficiency of the Rhodamine B was observed for TiO2 fibers annealed at 600 °C and containing 40% anatase and 60% rutile. This sample ensured 100% degradation of the dye in 20 min, and this amount significantly exceeds the photocatalytic activity of the commercial Degussa P25 photocatalyst and TiO2 samples obtained previously under hydrothermal conditions by the sol-gel method.

Electrospun Composite TiO2 Fibers for Color Tuning in Electrochromic Devices

Engineering one-dimensional (1D) nanostructures with multiple components can unlock properties that are not attainable by single elements alone. Herein, we use coaxial electrospinning for the synthesis of non-woven webs nanofibers with different metal(oxide) nanoparticles (NPs), i.e. silver (Ag), gold (Au), and copper oxide (CuO). The approach includes the structuring of nanofibers with an average diameter of 198.7±21.5 nm comprised of mesoporous TiO2 nanopowders mixed with metal(oxide) NPs to enable color tuning upon the application of an electrical potential. The nanofiber composites are supported on a fluorine-doped tin oxide (FTO) glass substrate and assembled in an electrochromic device in a half-cell configuration. It is observed that the color attained can be altered by changing the NP composition; such that Ag shows a black-brown color, Au yields dark blue, and CuO leads to a dark green color under negative bias. Fast color switching (<10 seconds) is possible per each TiO2 nanofiber/NP configuration. This is attributed to the faster kinetics of electrospun nanofibers in redox reactions gained by the high surface area to volume ratio. Band-gap deployment of the nanofiber composites is also observed, depending on the synthesized TiO2 nanofibers the band gap can be modulated between 2.76 to 3.01 eV allowing fine-color tuning upon EC cycles between ±2V. The rational design of the composite nanofibers is confirmed chemically, structurally and optically. The experiments show that material functionalities like color tuning are achievable with the use of metal(oxide) NPs. These findings can pave a new path for the rational design of nanofiber materials with applications in smart colored windows.

RETRACTED: Tin diselenide nanoflakes decorated hierarchical 1D TiO2 fiber: A robust and highly efficient co-catalyst for hydrogen evolution reaction

Abstract Transitional metal dichalcogenide two-dimensional materials have revealed many astonishing properties including as a substitution of noble metals as a co-catalyst for hydrogen evolution reaction. Tin diselenide (SnSe2) is the one who also received substantial consideration in many fields due to low cost, earth-abundant and environment-friendly. However, the great challenge to make heterojunction with other semiconductor material to improve its efficiency for photocatalytic water splitting. For this purpose, we have prepared a 1D nanofiber of TiO2 by electrospinning and produced a needle-like structure on the fiber by following the alkali hydrothermal method. The chemical vapor deposition method (CVD) was adopted to load nanoflakes of SnSe2 on the branched fiber of TiO2 and make a strong heterojunction. The composite interpreted excellent photocatalytic performance by producing hydrogen about 0.95 mmol g−1 h−1 in comparison with branched TiO2 (0.47 mmol g−1 h−1) and conventional TiO2 fiber (0.35 mmol g−1 h−1). The photoluminescence, time decay fluorescent spectra and photoelectrochemical results ratified that SnSe2 not only reduces the charge recombination by increasing the transfer of electron but also provides the active site for hydrogen production as a cocatalyst. This study presents an inexpensive and environmentally friendly photocatalyst for hydrogen production without the use of noble metals.

Hybridization of g-C3N4 quantum dots with 1D branched TiO2 fiber for efficient visible light-driven photocatalytic hydrogen generation

The hybrid 1D branched TiO2 loaded with g-C3N4 QDs was successfully fabricated that plays a significant role in photocatalysis. The 1D branched TiO2 prepared by electrospinning followed by alkali-hydrothermal process, and g-C3N4 QDs were grafted over it by a chemical vapor deposition method. The composite display enhancement in photocatalytic hydrogen evolution is about 10.57 mmol. g−1.h−1 in comparison to the g-C3N4 sample that only produces 0.32 mmol. g−1.h−1 while the HBTiO2 sample evolved a negligible amount of hydrogen under visible light. The composite sample shows quantum efficiency for HER at 420 nm light is 18.6% that is much higher than the other two samples. The specific surface area of the composite sample is 92.39 m2g-1 that is about 13 times more than bulk g-C3N4. The bandgap of HBTiO2/g-C3N4 QDs, g-C3N4, and HBTiO2 samples calculated as 2.71 eV, 2.67eV, and 3.24eV, respectively. The TRPL spectra imply that the duration of the lifetime of composite becomes longer which effectually overwhelm the electron-hole recombination. The 1D branched TiO2 fiber reduces the charge recombination by fast transfer of electron while g-C3N4 QDs facilitate the visible light absorption by improving the optical properties. The formation of the type II heterostructure system remarkably promotes the separation and transfer of electron holes and facilitates the photo-reduction reaction.