Improved hydrogen monitoring properties based on p-NiO/n-SnO2 heterojunction composite nanofibers

Here we demonstrate the preparation and improved hydrogen monitoring properties based on p-NiO/n-SnO2 heterojunction composite nanofibers via the electrospinning technique and calcination procedure. NiO/SnO2 heterojuction composite nanofibers were spin-coated on the ceramic tube with a pair of Au electrodes for the detection of hydrogen. Extremely fast response−recovery behavior (̰3s) has been obtained at the operable temperature of 320 °C, based on our gas sensor, with the detection limit of approximate 5 ppm H₂. The role of the addition of NiO into the SnO₂ nanofibers and the sensing mechanism has also been discussed in this work.

A novel alcohol detector based on ZrO2-doped SnO2 electrospun nanofibers

To overcome the interference of acetone when detecting alcohol, a novel alcohol detector based on zirconia-doped SnO2 nanofibers were fabricated through electrospinning technique and calcination process. The samples have been characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and their gas sensing properties have also been investigated. When exposed to alcohol vapor, the nanofibers containing 15 mol% zirconia exhibit the best sensing properties. Moreover, the sensor holds the successful discrimination between acetone and alcohol, which makes our product a good candidate in fabricating highly selective sensors in practice.

Highly efficient LaCoO3 nanofibers catalysts for photocatalytic degradation of rhodamine B

Perovskite-type oxide LaCoO₃ nanofibers have been fabricated by electrospinning and subsequent calcination technology. Scanning electron microscopy, transmission electron microscopy, and X-ray diffraction were used to characterize the morphology and structure. Rhodamine B (RhB) was used to evaluate the ultraviolet photocatalytic activity of the as-prepared nanofibers. The effect of calcination temperature and pH of the reaction solution on the decolorization of RhB were investigated. Results showed that the samples calcined at 600°C exhibited the best photocatalytic activity at pH 4. Additionally, the recycling experiments confirmed the attractive stability of the catalysts.

Na+-doped zinc oxide nanofiber membrane for high speed humidity sensor

A novel sensitive humidity nanosensor based on Na1-doped ZnO nanofiber membrane has been prepared via electrospinning and calcination. The product was characterized by scanning electron microscopy and X-ray diffraction. During the whole relative humidity (11%–95%) measurement, the response and recovery time is about 3 and 6 s, respectively, with good linearity, and reproducibility. These remarkable and sensitive sensing performances make our product a good candidate in fabricating humidity sensors.

Au-doped polyacrylonitrile-polyaniline core-shell electrospun nanofibers having high field-effect mobilities

Au-doped polyacrylonitrile–polyaniline core–shell nanofibers are fabricated via electrospinning and subsequent gas-phase polymerization, providing a very high field-effect mobility of up to 11.6 cm² V⁻¹ s⁻¹. This method is also suitable for other conducting polymers and may eventually lead to a new and simplified fabrication of high-performance polymer organic field-effect transistors.

A novel non-enzymatic glucose sensor based on nickel (II) oxide electrospun nanofibers

A new enzymeless glucose sensor has been fabricated via electrospinning technology and subsequent calcination. The morphology and structure of the as-prepared nanofibers have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The electrocatalytic oxidation of glucose in alkaline medium at nickel oxide modified glassy carbon electrodes has been investigated. The modified electrodes offer excellent electrocatalytic activity toward the glucose oxidation at low positive potential (0.3 V). Glucose has been determined chronoamperometrically at the surface of NiO nanofibers modified electrode in 0.5 mM NaOH. Under the optimized condition, the calibration curve is linear in the concentration range of 2 × 10−3 mM∼1 mM, and 1 mM∼9.5 mM. The detection limit (signal-to-noise 3) and response time are 3.394 × 10−6 M and 2 s, respectively. The NiO electrospun nanofibers is easy to prepare and feasible in economy. The modified electrode is steady and can be used repeatedly, so it is reasonable to expect its broad use in non-enzymatic glucose sensor.

Power generation from randomly oriented electrospun nanofiber membranes

Randomly orientated electrospun poly(vinylidene fluoride) nanofiber membranes were directly used as active layers to make mechanical-to-electrical energy conversion devices. Without any extra poling treatment, the device can generate high electrical outputs upon receiving a mechanical impact. The device also showed long-term working stability and ability to drive electronic devices. Such a nanofiber membrane device may serve as a simple but efficient energy source for self-powered electronics.

Carbon nanofibers with inter-bonded fibrous structure for supercapacitor application

In this study, we have improved carbon nanofiber interconnection by using two electrospinning methods: conventional electrospinning and side-by-side bicomponent electrospinning to produce polyvinylpyrrolidone (PVP)/polyacrylonitrile (PAN) blend nanofibers and PVP/PAN side-by-side bicomponent nanofibers respectively. Upon carbonization, the nanofibers showed inter-bonded morphologies. PVP here functioned to bind nanofibers during carbonization. The inter-boned fibrous morphology was highly affected by the PVP/PAN ratio and the electrospinning method. Carbon nanofibers prepared by the bicomponent electrospinning were found to have larger capacitances compared to those prepared by the conventional electrospinning. The influence of electrospinning method, PAN/PVP ratio on the crystallinity of carbon nanofibers, their surface morphology and capacitor performance were examined. The influence mechanism was elucidated as well.

Experimental verification of theoretical prediction of fiber to fiber contacts in electrospun multilayer nano-microfibrous assemblies: effect of fiber diameter and network porosity

Average number of fiber-to-fiber contacts in a fibrous structure is a prerequisite to investigate the mechanical, optical and transport properties of stochastic nanomicrofibrous networks. In this research work, based on theoretical analysis presented for the estimation of the number of contacts between fibers in electrospun random multilayer nanofibrous assembles, experimental verification for theoretical dependence of fiber diameter and network porosity on the fiber to fiber contacts has been provided. The analytical model formulated is compared with the existing theories to predict the average number of fiber contacts of nanofiber structures. The effect of fiber diameters and network porosities on average number of fiber contacts of nano-microfiber mats has been investigated. A comparison is also made between the experimental and theoretical number of inter-fiber contacts of multilayer electrospun random nanomicrofibrous networks. It has been found that both the fiber diameter and the network porosity have significant effects on the properties of fiber-to-fiber contacts.