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Metal–Organic Framework-Assisted Construction of TiO <sub/>2</sub> /Co <sub/>3</sub> O <sub/>4</sub> Highly Ordered Necklace-like Heterostructures for Enhanced Ethanol Vapor Sensing Performance
摘要： In this work, we report a metal-organic frameworks (MOFs)-assisted strategy to synthesize necklace-like TiO2/Co3O4 nanofibers with highly ordered heterostructures via a facile approach including electrospinning and subsequent calcination. Polycrystalline TiO2 nanofiber and Co3O4 nanocage are consummate interconnected to form highly ordered heterogeneous nanostructure, which can be benefit for precisely accommodating the interface resistance of the p-n heterojunctions and future realization of improved materials performance. The ethanol gas-sensing investigation showed that TiO2/Co3O4 nanofibers sensors exhibited high ethanol response (Rair/Rgas -1 = 16.7 @ 150 ppm) and low operating temperature of 150 °C. The sensing enhancement mechanism of the TiO2/Co3O4 nanofibers is related to the formation of heterojunction at interfaces and the high catalytic activity of MOF-derived Co3O4. Furthermore, this versatile method is a promising approach to construct ordered heterostructures and extend the MOF-based heterogeneous materials toward wide applications.
关键词： Ordered Heterostructures,MOF-assisted,Ethanol vapor detect,Heterogeneous Nanofiber,Gas sensor
更新于2025-09-10 09:29:36
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Electrospun Three-Dimensional Nanofibrous Structure via Probe Arrays Inducing
摘要： The fast and precise direct-printing of micro three-dimensional (3D) structures is the important development trend for micro/nano fabrication technique. A novel method with probe arrays was built up to realize the controllable deposition of 3D electrospun nanofibrous structures. Firstly, several 3D nanofibrous structures were built on a single probe and 2-, 3-probes, which indicated that the probe height and probe interval played a key role on the 3D structure morphology. Then, different stereo nanofibrous structures based on multiprobe arrays were achieved accurately and the effects of processing parameters, including the probe height, probe interval, applied voltage and flow rate on the deposition behaviors of electrospun nanofiber over the probe arrays were investigated. The deposition area of 3D electrospun nanofibrous structures decreased with the increase of probe interval, applied voltage, and flow rate. Several 3D nanofibrous structures of special shapes including convex, triangle wave, inverted cone and complex curved surface were demonstrated by controlling the configuration of probe arrays and electrospinning parameters. This work provides an effective and simple way for the construction of 3D electrospun nanofibrous structures, which has great potentials in various medical and industrial applications.
关键词： three-dimensional micro structures,nanofiber,electrospinning,probe arrays,induced electrical field
更新于2025-09-10 09:29:36
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Electrospun Nanofibers Containing TiO2 for the Photocatalytic Degradation of Ethylene and Delaying Postharvest Ripening of Bananas
摘要： The study aimed to develop a nanofiber film for photocatalytic degradation of ethylene and slowing down the ripening of banana fruit. Nanofibers containing different amounts of TiO2 nanoparticles (1 wt%, 5 wt%, and 10 wt%) were prepared using electrospinning method. Nanofibers containing 5 wt% TiO2 exhibited a nano-scale structure, good nanoparticle uniformity, and an anatase phase as characterized by scanning electron microscopy, energy dispersive X-ray spectrometer, transmission electron microscopy, and X-ray diffraction. Nanofibers containing 5 wt% TiO2 were tested in a photocatalytic reactor and showed higher photocatalytic activity for the degradation of ethylene. The utility of the photocatalytic reaction was further confirmed via a banana fruit-ripening test. The TiO2 nanofiber successfully delayed the color change and softening of bananas during storage. The results suggest that the TiO2 nanofiber offers photocatalytic degradation of ethylene and could potentially be used as packaging material for delaying postharvest fruit ripening.
关键词： Electrospun nanofiber,TiO2,Banana ripening,Ethylene degradation,Photocatalysis
更新于2025-09-10 09:29:36
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Decoration of SrTiO3 nanofibers by BiOI for photocatalytic methyl orange degradation under visible light irradiation
摘要： BiOI decorated electrospun SrTiO3 nanofibers (BE) with a spiky club structure were fabricated using a rapid microwave-assisted solvothermal method. The exposed (102) plane of BiOI preferentially coupled with the electrospun SrTiO3 fibers aiming to achieve charge neutrality. XRD analysis demonstrated that a BE composite coupled with an optimal content of BiOI exhibited few crystal imperfections. The resulting BE samples showed a higher degradation efficiency towards methyl orange dye under visible light irradiation (λ > 400 nm) compared to the individual BiOI and SrTiO3. The BE composite possessed a high degradation rate of 0.015 (kapp, min–1) and a normalized rate constant of 2.46 × 10–3 (kapp/surface area), which was 7.7 and 1120 times higher than those of BiOI and SrTiO3 alone, and a degradation level over 94.6% within 3 h of irradiation under visible light. The high photocatalytic activity could be attributed to the heterostructure formation, p-n junction at the BE interface, high contact between water and dye molecules with the BiOI covered surface, and extended visible light absorption. This work provides an effective approach to produce BE nanofibers for dealing with methyl orange dye and proves that BE composites have the potential to serve as visible-light-driven photocatalysts.
关键词： Visible light irradiation,Photocatalyst,SrTiO3,BiOI,Nanofiber
更新于2025-09-09 09:28:46
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Hemoglobin Immobilization on Multiporous Nanofibers of SnO <sub/>2</sub> and Chitosan Composite for Hydrogen Peroxide Sensing
摘要： A multiporous nanofiber (MPNFs) of SnO2 and chitosan has been used for the immobilization of a redox protein, hemoglobin (Hb), onto the surface of glassy carbon electrode (GCE). The multiporous nanofiber of SnO2 that has very high surface area is synthesized by using electrospinning technique through controlling the tin precursor concentration. Since the constructed MPNFs of SnO2 exposes very high surface area, it increases the efficiency for biomolecule-loading. The morphology of fabricated electrodes is examined by SEM observation and the absorbance spectra of Hb/(MPNFs) of SnO2 are studied by UV-Vis analysis. Cyclic Voltammetry and amperometry are employed to study and optimize the performance of the resulting fabricated electrode. After fabrication of the electrode with the Hb and MPNFs of SnO2, a direct electron transfer between the protein’s redox centre and the glassy carbon electrode was established. The modified electrode has showed a couple of redox peak located at ?0.29 V and ?0.18 V and found to be sensitive to H2O2. The fabricated electrode also exhibited an excellent electrocatalytic activity towards the reduction of H2O2. The catalysis currents increased linearly to the H2O2 concentration in a wide range of 5.0 × 10?6–1.5 × 10?4 M. Overall experimental results show that MPNFs of SnO2 has a role towards the enhancement of the electroactivity of Hb at the electrode surface. Thus the MPNFs of SnO2 is a very promising candidate for future biosensor applications.
关键词： Multiporous SnO2 Nanofiber,Hemoglobin,Electrical Contact,H2O2 Sensing,Direct Electrochemistry
更新于2025-09-09 09:28:46
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Photostability of oxygen-sensitive core-shell nanofibers
摘要： Core-shell electrospun nanofibers constitute a vehicle enabling novel uses for phosphorescent oxygen-sensitive molecules. In this work, we investigate compositional parameters and other factors governing fiber design appropriate to long-term sensor applications. These nanofibers contain an oxygen-sensitive palladium (II) porphyrin species within a polysulfone core; an outer polycaprolactone shell protects the core from the surrounding environment. The presence of a core-shell architecture was confirmed using advanced time-of-flight secondary ion mass spectrometry (ToF-SIMS). Although these sensors exhibit excellent photostability in the short-term, long-term exposures (up to 1,000 hr) are shown to detrimentally impact performance via photobleaching phenomenon. We also investigated higher porphyrin concentrations to determine whether the resulting sensors are predisposed to photobleaching. High porphyrin loadings (up to 10 wt%) could be successfully incorporated into the core. While increased probe content should logically enhance emission intensity, we sought to investigate the balance between a stronger signal and the potential for decreased photostability. The resulting behavior is rationalized by (1) establishing the spacing associated with a ‘perfect’ molecular dispersion and (2) invoking five distinct populations of porphyrin agglomeration. Populations that are not molecularly dispersed experience varying degrees of agglomeration-catalyzed photobleaching. The photobleaching rate increases with the extent of agglomeration and, therefore, the initial porphyrin content. Although it is demonstrated that low porphyrin loadings exhibit improved photobleaching resistance, the initial brightness is inadequate. In contrast, enhanced brightness via increased porphyrin content also leads to diminishing returns due to the apparent emergence of a self-quenched population. For a given application, selection of an appropriate porphyrin concentration is critical to achieving a compromise between initial brightness and photobleaching resistance. Detector sensitivity and anticipated duration of use must be considered when weighing the relative benefits of these attributes and selecting a specific porphyrin content.
关键词： Core-shell electrospinning,electrospun nanofiber,agglomeration,porphyrin,oxygen sensing
更新于2025-09-09 09:28:46
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High-Throughput Template-Free Continuous Flow Synthesis of Polyaniline Nanofibers
摘要： The large-scale and high-throughput synthesis of conjugated polymer based nanofibers always remain a challenge for the chemists due to the issues related to secondary nucleation in traditional batch processes. Typically polyaniline (PANI) nanofibers are synthesized under highly dilute conditions resulting in a very low throughput of few hundred mg per hour and a low space-time yield (STY) of 1-2 g·L-1·h-1. In this manuscript, we report the continuous flow synthesis of PANI nanofibers which results in high throughput (17-30 g·h-1) and high space-time yield (140-450 g·L-1·h-1). These polyaniline nanofibers show high surface area (42 m2·g-1), high specific capacitance (577 F·g-1) and high crystallinity. Finally, the present method is generic in nature and, in principle, can be extended for the synthesis of nanofibers of other conjugated polymers via oxidative polymerization.
关键词： Chemical oxidative polymerization,One-dimensional nanomaterials,Polyaniline nanofiber,Space-time yield,Electrochemical capacitor,Throughput,Continuous flow synthesis
更新于2025-09-09 09:28:46
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Microcystis aeruginosa Synergistically Facilitate the Photocatalytic Degradation of Tetracycline Hydrochloride and Cr(VI) on PAN/TiO2/Ag Nanofiber Mats
摘要： Cyanobacterial blooms can cause serious damage to aquatic ecosystems. However, we have demonstrated that typical algae-blooming species Microcystis aeruginosa (M. aeruginosa) combined with photocatalysts could synergistically facilitate the photodecontamination of tetracycline hydrochloride (TC) and Cr(VI). In this study, for the first time, harmful algae were successfully converted into photoreactive bionano hybrid materials by immobilizing M. aeruginosa cells onto polyacrylonitrile (PAN)-TiO2/Ag hybrid nanofibers, and their photocatalytic activity was evaluated. The addition of M. aeruginosa significantly improved the photodecontamination, and the reaction rate constant (k) values of TC and Cr(VI) degradation by M. aeruginosa-PAN/TiO2/Ag nanofiber mats were 2.4 and 1.5-fold higher than that of bare PAN/TiO2/Ag nanofiber. Photoreaction caused damage to algae cells, but no microcystin was found that had been photodegraded simultaneously. The effects of various active species were also investigated, and the photodegradation mechanism was proposed. Recycling tests revealed that this flexible M. aeruginosa-PAN/TiO2/Ag hybrid mat had potential application in the removal of mixed organic and inorganic pollutants with high efficiency and without secondary pollutants. Thus, harmful algae blooms could serve as an efficient materials to remove toxic pollutants in a sustainable way under visible light irradiation.
关键词： Ag nanoparticles,PAN nanofiber,Cr(VI),tetracycline,TiO2 photocatalytic,Microcystis aeruginosa
更新于2025-09-04 15:30:14
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Solution electrowriting of highly stable TiN nanofiber pattern for transparent electrode under extreme environment
摘要： The fast developing electronic industry boosts higher demand of transparent electrode. Nanofiber network design provides a new platform for finding alternative materials to replace the traditional indium-doped tin oxide (ITO) film as transparent electrode. In this work, the TiN nanofiber network with a micron-scale precise geometry was firstly assembled by solution electrowriting. Unlike the ordinary opaque TiN film or bulk, the geometry patterned TiN nanofiber network achieved an ultrahigh transparency above 90%. Due to the electrical conductive virtue of TiN, the network reached a relatively low sheet resistance of 10.3 Ω/sq that can be comparable to ITO and even metal nanofibers. The combination of high transparency and low sheet resistance in TiN nanofiber network paves a way for its application as transparent electrode. Moreover, the figure-of-merit of TiN nanofiber transparent electrode was controllable by simply adjusting the geometry size of TiN nanofiber pattern. A series of oxidation resistance and corrosion resistance tests were additionally carried out, which caused little effect on the performance of TiN nanofiber transparent electrode. This excellent antioxidative and anticorrosive property demonstrates the high chemical durability of TiN nanofiber network, especially compared to metal nanofiber networks.
关键词： Solution electrospinning,Transparent electrode,Figure of merit,Nanofiber network,Chemical stability
更新于2025-09-04 15:30:14