The study of short- and medium-range order in oxyfluoroniobate glasses

Ignatieva, L. N.; Савченко, Н. Н.; Surovtsev, N. V.; Adichtchev, S. V.; Marchenko, Yurii B.; Bouznik, V. M.

doi:10.1016/j.jnoncrysol.2013.12.013

Cited by 11 publications

(5 citation statements)

References 19 publications

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“…6. The results indicate that both NOF and NOF/CNTs exhibit typical Nb–F vibrational band2, O = Nb = O twisting band25 and Nb–O–Nb stretching vibration band26 at 126.5 cm −1 , 226.5 cm −1 and 709.5 cm −1 . Compared with NOF, all the intensities of typical peaks obviously decrease after addition of CNTs.…”

Section: Resultsmentioning

confidence: 92%

CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

Huang

Yan

et al. 2017

Sci Rep

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Novel semiconductor photocatalysts have been the research focus and received much attention in recent years. The key issues for novel semiconductor photocatalysts are to effectively harvest solar energy and enhance the separation efficiency of the electron-hole pairs. In this work, novel Nb3O7F/CNTs hybrid nanocomposites with enhanced photocatalytic activity have been successfully synthesized by a facile hydrothermal plus etching technique. The important finding is that appropriate pH values lead to the formation of Nb3O7F nanocrystal directly. A general strategy to introdue interaction between Nb3O7F and CNTs markedly enhances the photocatalytic activity of Nb3O7F. Comparatively, Nb3O7F/CNTs nanocomposites exhibit higher photodegradation efficiency and faster photodegradation rate in the solution of methylene blue (MB) under visible-light irradiation. The higher photocatalytic activity may be attributed to more exposed active sites, higher carrier migration and narrower bandgap because of good synergistic effect. The results here may inspire more engineering, new design and facile fabrication of novel photocatalysts with highly photocatalytic activity.

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Section: Resultsmentioning

confidence: 92%

CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

Huang

Yan

et al. 2017

Sci Rep

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“…Figure 3 indicates that the main vibrational modes for the NOF and NOF/WS samples follow the ReO 3 type symmetry. For the pure NOF sample, the typical absorption bands at 122, 221, and 711 cm −1 can be attributed to the Nb-F vibrational mode, O=Nb=O twisting mode, and Nb-O-Nb stretching vibration band of the NbO 6 octahedra, respectively [7,30,31]. Compared with pure NOF, all the intensities of typical peaks obviously decrease after the addition of WS, which may potentially result from the weak crystallization of WS.…”

Section: Resultsmentioning

confidence: 97%

Novel Nb₃O₇F/WS₂ hybrid nanomaterials with enhanced optical absorption and photocatalytic activity

Huang¹,

Li²,

Yan³

et al. 2017

Nanotechnology

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Coping with increasing environmental issues, niobium oxyfluoride (NbOF), as a novel semiconductor, is a promising photocatalyst due to its outstanding electronic and optoelectronic properties. However, the photocatalytic performance of NbOF is restricted in practical application due to its weak optical absorption and low carrier separation. In this work, NbOF/WS hybrids with superior optical absorption and photocatalytic activity have been successfully synthesized by a facile two-step sol-hydrothermal technique. UV-vis spectra show that WS not only exhibits enhanced optical absorption in the range of 420-1100 nm but extends the absorption edge, and tends to narrow the band gap of the NbOF photocatalyst. Photocatalytic experiments indicate that introducing WS into NbOF markedly enhances the photocatalytic activity in the degradation of methylene blue dyes under visible-light irradiation. NbOF/WS photocatalysts exhibit the highest activity with 98.9% decoloration efficiency in 70 min, while pure NbOF only achieves 67.9% in the same time and achieves its final decoloration ratio after 150 min. The excellent photocatalytic activity can be directly ascribed to more exposed active sites, higher carrier separation efficiency, and faster carrier transfer. The results may open up a new avenue for the design and preparation of novel and highly efficient photocatalysts.

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“…Oxyfluoride glasses and glass-ceramics are considered to be promising host materials for active rare-earth ion centers. − These materials possess high optical transparency and good mechanical and chemical properties − and are of special interest for practical applications, such as in optical amplifiers, up-conversion materials, ,, light-emitting diodes, magneto-optical materials, and temperature sensors . In addition, oxyfluoride glasses may exhibit relatively high ionic conductivity because of the presence of fluorine ions. − …”

Section: Introductionmentioning

confidence: 99%

Magnetic Resonance and Conductivity Study of Lead–Cadmium Fluorosilicate Glasses and Glass-Ceramics

et al. 2018

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The fluorine motional dynamics in fluorosilicate glasses and glass-ceramics of the SiO2–PbF2–CdF2 system was investigated by complex impedance spectroscopy and 19F nuclear magnetic resonance (NMR) spectroscopy, and the coordination environment of a Cu2+ paramagnetic probe was examined by electron paramagnetic resonance (EPR) spectroscopy. Glass-ceramics were obtained by heat treatment of glass at a temperature between the glass-transition (T g) and the onset of crystallization (T x). Ionic conductivity of about 1.6 × 10–4 S/cm was obtained at 500 K for glass. The conductivity of the glass-ceramics was found to be lower than that obtained for the glass. The temperature dependence of the 19F NMR spin–lattice relaxation times was investigated between 300 and 770 K. The 19F NMR results of glass exhibit the qualitative features associated with fluorine mobility, namely, the presence of a relaxation rate maximum below T g. The NMR relaxation data of the glass-ceramics were analyzed assuming two fluorine dynamics. Continuous-wave EPR spectroscopy, using a Cu2+ ion as a probe, was employed to determine the local symmetry of the ion environment and the nature of relevant spin interactions. The hyperfine coupling of Cu2+ with the 19F, 113Cd, and 207Pb nuclei in the glass and the glass-ceramic was investigated by electron spin echo envelope modulation and hyperfine sublevel correlation spectroscopy.

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The study of short- and medium-range order in oxyfluoroniobate glasses

Cited by 11 publications

References 19 publications

CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

Novel Nb₃O₇F/WS₂ hybrid nanomaterials with enhanced optical absorption and photocatalytic activity

Magnetic Resonance and Conductivity Study of Lead–Cadmium Fluorosilicate Glasses and Glass-Ceramics

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The study of short- and medium-range order in oxyfluoroniobate glasses

Cited by 11 publications

References 19 publications

CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

CNTs-Modified Nb3O7F Hybrid Nanocrystal towards Faster Carrier Migration, Lower Bandgap and Higher Photocatalytic Activity

Novel Nb3O7F/WS2 hybrid nanomaterials with enhanced optical absorption and photocatalytic activity

Magnetic Resonance and Conductivity Study of Lead–Cadmium Fluorosilicate Glasses and Glass-Ceramics

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Novel Nb₃O₇F/WS₂ hybrid nanomaterials with enhanced optical absorption and photocatalytic activity