Xianfeng Meng

Fabrication and Characterization of Heterostructural CoFe2O4/ Pb(Zr0.52Ti0.48)O3 Nanofibers by Electrospinning

Heterostructural CoFe2O4/Pb(Zr0.52Ti 0.48)O3 composite nanofibers with diameters about 100 nm were prepared by electrospinning. The thermal decomposition process, structure and morphology of the precursor composite fibers and the calcined CoFe 2O4/Pb(Zr0.52Ti0.48)O3 nanofibers were investigated by thermogravimetric and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). It is found that just the spinel CoFe2O4 (CFO) and perovskite Pb(Zr0.52Ti 0.48)O3 (PZT) phases coexist in the composite CFO/PZT nanofibers obtained at calcination temperature of 950°C. The grain sizes of CFO and PZT increase with the calcination temperature whilst the grain growth process would be limited due to the separation effects for these two phases. When the grain sizes of CFO and PZT in the nanofiber reach about the size range of the nanofiber diameter, these grains are alternatively distributed along the nanofiber length direction and the well-defined heterostructure is formed between these nanograins of CFO and PZT.

Microwave absorbing characteristics of nanocrystalline Fe0.13(CoxNi100−x)0.87 alloy fine fiber–epoxy resin composites

The nanocrystalline Fe0.13(Co x Ni100− x )0.87 (x = 30, 50, and 80) alloy fiber 50 wt%–epoxy resin composites were prepared by mixing epoxy resin with the alloy fibers. The electromagnetic parameters of the composites were measured using the coaxial line method and the reflection loss was calculated at a frequency range 1–18 GHz. The results show that the nanocrystalline Fe0.13(Co x Ni100− x )0.87 alloy fiber–epoxy resin composites have effective microwave absorption characteristics in radar band, which are mainly influenced by the nanocrystalline alloy composition and the composite thickness. This microwave absorption effect largely arises from the eddy current, ferromagnetic resonance, and dielectric loss in the composite.

Facile Preparation and Photocatalytic Properties of TiO2 Fiber Membrane with Wrinkle Structure

Herein, TiO₂ fiber membrane with wrinkle structure was fabricated by an electrospinning technique in combination with a sol-gel process. The as-prepared TiO₂ membranes were interwoven with interconnected nanofibers. The surfacial and morphological features of the obtained TiO₂ fiber membrane could be tuned by varying the content of the precursor, titanium (IV) n-butoxide. The nature of wrinkle structure and high surface area demonstrates an impact on the electron-hole separation and charge transfer during photocatalytic tests, thereby leading to an obvious enhancement in the photocatalytic performance. The results revealed the resultant TPNs-20 sample displayed the best photocatalytic performance toward the removal of methyl orange (MO), and its degradation degree was up to 97% within 70 min. Furthermore, a photocatalytic mechanism is proposed on the basis of results and analysis, which indicates that ˙OH and ˙O-₂ radicals are the main reactive species responsbile for the enhanced photocatalytic activity. We anticipate that controllable synthesis of promising TiO₂ fiber membranes in this study provides new insight into the development of efficient photocatalysts for high-performance environmental remediation.