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• Carbon micro- and nanofibers were prepared by using gyration. • The distribution of fiber diameter showed a normal law with 400-600 nm. • GO changes the orderly arrangement of fibers into a network structure. • The conductivity of carbon nanofibers is greatly improved by adding GO. • When GO was added, the electrode showed excellent electrochemical performance. In this paper, graphene oxide (GO) were added into polyacrylonitrile to prepare carbon nanofiber by using gyration and subsequent carbonization process as to improve their electrochemical properties. The microstructure and electrochemical properties of prepared carbon nanofiber samples were investigated by using scanning electron microscopy and electrochemical workstation, respectively. The effects of the addition amount of graphene oxide and carbonation temperature on the microstructure and electrochemical properties of composite carbon nanofibers were studied. [ABSTRACT FROM AUTHOR]

Carbon nanofibers were prepared by using centrifugal spinning with polyacrylonitrile as precursor. The microstructure and electrochemical properties of prepared samples were investigated by using scanning electron microscopy and electrochemical workstation, respectively. The results showed that the distribution of fiber diameter showed a normal law. The carbon fibers present good cycle stability at low scan rate. Moreover, the integral area of cyclic voltammetry curve reaches the maximum when the mass ratio of PAN/PMMA is 20:3. The specific capacitance of it is 102 F/g and 84 F/g, in case of the current density at 0.1 A/g and 0.2 A/g, respectively. [ABSTRACT FROM AUTHOR]

The single-component BiOCl:Dy3+ white-light-emitting phosphor was successfully prepared. The luminescence performance with excellent thermal stability indicated that this as-prepared product could act as a high-performance phosphor candidate for n-UV w-LED application. • The single-component BiOCl:Dy3+ phosphor was prepared successfully. • The phosphor emitted white light under the excitation in n-UV light region. • The PL properties obtained excellent thermal stability at higher temperatures. • The phosphor could have great potential for n-UV w-LED application. The advantages of single-component white-light-emitting phosphor make it more important for n-UV-light emitting diodes with excellent properties and efficiency. Herein, the BiOCl:Dy3+ white-light-emitting phosphor was firstly prepared by high temperature solid-state reaction. And the crystal structure, luminescence properties, lifetime, and thermal quenching behavior were carried out in detail. The results revealed that the BiOCl:Dy3+ phosphor could be excited efficiently in a broad near ultraviolet (n-UV) light region, which matched well with the n-UV chips for w-LEDs. Under the excitation at 390 nm, the BiOCl:Dy3+ phosphor exhibited white light with three emission peaks centered at 481, 575, and 664 nm, respectively. The optimal doping concentration of Dy3+ ions was found to be x = 0.03, and exchange interaction was confirmed to result in the concentration quenching. Furthermore, when the test temperature turned up to 150 °C, the intensity of emission peaks at 481 and 575 nm could still remain 77.96% and 77.93% of the initial intensity at room temperature. With the their activation energy of 0.33 eV and 0.27 eV, the excellent thermal stability of the BiOCl:Dy3+ phosphor were confirmed. All these results indicated that this as-prepared product could act as a high-performance phosphor candidate for n-UV w-LED application. [ABSTRACT FROM AUTHOR]

Graphical abstract Na 3 GdP 2 O 8 : Sm3+ and Na 3 GdP 2 O 8 : Dy3+ phosphors were successfully prepared and emitted orange-red and white light under UV/NUV excitation, respectively. The excellent thermal stability further indicated that these phosphors have great potential for applications in UV/NUV excited w-LEDs. Highlights • The novel Sm3+ and Dy3+ ions doped Na 3 GdP 2 O 8 phosphors were prepared. • Both orange-red and white lights could obtain with excellent thermal stability. • These phosphors are potential for application in UV/NUV based w-LEDs. Abstract With the rapid demand of white light emitting diodes (w-LEDs), studies on the ultraviolet/near-ultraviolet (UV/NUV) light excited phosphors are becoming more and more important. Herein the novel Na 3 GdP 2 O 8 : Re3+ (Re = Sm, Dy) phosphors were synthesized through a high-temperature solid-state reaction method. The Sm3+-doped Na 3 GdP 2 O 8 phosphors emitted orange-red light centered at 600 nm, under the NUV excitation at 403 nm. When excited at 350 nm, the Na 3 GdP 2 O 8 : Dy3+ phosphors presented a white light emission, including three peaks at 483, 578, and 670 nm, respectively. In addition, both of the Na 3 GdP 2 O 8 : Sm3+ and Na 3 GdP 2 O 8 : Dy3+ phosphors showed excellent thermal stability at different temperatures, of which the emission intensities at 150 °C could maintain about 75% and 79% of those at room temperature, respectively. These results indicate that the as-prepared phosphors can be considered as potential candidates for applications in UV/NUV excited w-LEDs. [ABSTRACT FROM AUTHOR]

Currently, phase change materials (PCMs) composite fibers are typically prepared by electrospinning. However, electrospinning exhibits safety concerns and a low production rate, which limit its practical applications as a cost-effective fiber fabrication approach. Therefore, a novel, and simple centrifugal spinning technology is employed to extrude fibers from composite solutions using a high-speed rotary and perforated spinneret. The composite fibers based on polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) were prepared by centrifugal spinning. The SEM of PVP/PEG composite fibers indicated that the fibrous morphology is well preserved. The DSC and TGA indicated that PVP/PEG composite fibers exhibit good thermal properties. [ABSTRACT FROM AUTHOR]

NaNb x Ta 1−x O 3 perovskite photocatalysts with cubic microstructures were synthesized by the molten salt method. Furthermore, the photocatalysts were characterized in detail by XRD, SEM, TEM, XPS, PL. SEM results indicated that the added Nb significantly affects the microstructure. XPS results confirmed the presence of the Nb 5+ dopant in NaNb x Ta 1−x O 3 . Compared to NaTaO 3 , the catalyst doped with Nb significantly affected the photocatalytic production of hydrogen in an aqueous solution and the photocatalytic degradation of RhB under UV light irradiation. NaNb 0.5 Ta 0.5 O 3 exhibited the best activity for the photocatalytic degradation of RhB as well as excellent performance for the photocatalytic production of hydrogen. [ABSTRACT FROM AUTHOR]

A series of apatite-type phosphors Ba 4.97− x Sr x (PO 4 ) 3 Cl:Eu 2+ ( x = 0, 0.5, 1.0, 1.5, 2.0) were synthesized by the high temperature solid-state reaction method, and its luminescence properties were investigated in detail. It can be found that a red shift of the emission peak wavelength emerged from 439 to 462 nm with the continuous introduction of Sr 2+ into the crystal lattice which has been simulated by a crystal-field model. The red shift is explained by the distortion in the crystal structure through X-ray diffraction and the Rietveld refinement analysis. According to a recently raised structural model, Eu 2+ ions are surrounded by O atoms, PO 4 tetrahedrons and Ba/Sr ions. After introducing Sr 2+ into the lattice, the interatomic distance between Ba/Sr atoms and Eu 2+ was expected to become shorter, resulting in a distortion of the inner EuO n polyhedrons. Then the crystal field strength surrounding Eu 2+ was increased, finally resulting in the red shift. [ABSTRACT FROM AUTHOR]

Cyan-emitting LiBaBO 3 :Eu 2+ phosphor was synthesized by solid-state reaction at 800 °C. Structure refinement by Rietveld method reveals that LiBaBO 3 crystallizes in a monoclinic cell, space groups P 2 1 / c or P 2 1 / n . Upon 365 nm excitation, LiBaBO 3 :Eu 2+ shows a symmetric emission band peaking at 496 nm with full-width at half-maximum of 80 nm; when monitoring at 496 nm, a broad excitation band in the UV region (250–420 nm) is observed. The luminescence property of LiBaBO 3 :Eu 2+ is considerably different from LiSrBO 3 :Eu 2+ which holds the same space group. The local structures of the two hosts are compared to explain the different behaviors of Eu 2+ . [ABSTRACT FROM AUTHOR]