- Microwave–assisted synthesis of nanoscale tungsten trioxide hydrate with excellent photocatalytic activity under visible irradiation
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Tungsten trioxide hydrate (WO3?1/3H2O) nanoparticles (NPs) were prepared via a microwave–assisted synthetic pathway by using Na2WO4·2H2O and PdCl2 as precursors. Microstructure and morphology of as–prepared WO3?1/3H2O NPs were investigated through X–ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier transform infrared (FT–IR) spectra, while porosity and bandgap through specific surface area and UV–vis absorption spectroscopy. It was found that Pd2+ ions played a crucial role in the formation of WO3?1/3H2O NPs, and thus a possible formation mechanism was proposed based on the growth processes. The photocatalytic property of WO3?1/3H2O NPs was evaluated on the basis of Rhodamine B (RhB) degradation in aqueous solutions under simulated visible irradiation. Photocatalytic experimental results indicated that as–prepared WO3?1/3H2O NPs exhibited much more superior photocatalytic activity by contrast to that of the commercial WO3.
- Cai, Feng–Ying,Cao, Wei,Lü, Jian,Li, Taohai,Liu, Heng–Xin,Shen, Yanhua,Xu, Jian–Ying,Yu, Xu–Teng
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- Synthesis of a highly reactive form of WO2Cl2, its conversion into nanocrystalline mono-hydrated WO3 and coordination compounds with tetramethylurea
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A new form of WO2Cl2 was obtained by modification of a literature procedure. Both the newly prepared WO2Cl2 and the commercial yellow WO2Cl2 exhibited an orthorhombic structure (powder X-ray diffraction, P-XRD), and their air exposure at room temperature afforded light green and lemon yellow WO3·H2O (orthorhombic phase), respectively. These materials were characterized by P-XRD, high-resolution transmission electron microscopy (HR-TEM) and scanning transmission electron microscopy (S-TEM). The analyses revealed the nanocrystalline nature of light green WO3·H2O, and the prevalent amorphism of lemon yellow WO3·H2O. The reactions of grey WO2Cl2 with one and two equivalents of tetramethylurea (tmu), in CH2Cl2 at room temperature, led to the isolation of the trinuclear complex [WO2Cl2(tmu)]3, 1 (45% yield), and the mononuclear one WO2Cl2(tmu)2, 2 (64%), respectively. Compounds 1 and 2 were fully characterized by analytical and spectroscopic methods, single crystal X-ray diffraction (SC-XRD) and DFT calculations.
- Bortoluzzi, Marco,Evangelisti, Claudio,Marchetti, Fabio,Pampaloni, Guido,Piccinelli, Fabio,Zacchini, Stefano
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p. 15342 - 15349
(2016/10/13)
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- Improvement of electroactive β phase nucleation and dielectric properties of WO3·H2O nanoparticle loaded poly(vinylidene fluoride) thin films
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Tungsten oxide hydrate (WO3·H2O) nanoparticles (NPs) have been prepared by simple hydrazine hydrate reduction. X-ray diffraction, UV-Visible spectroscopy and field emission electron scanning microscopy confirm the formation of phase pure orthorhombic WO3·H2O NPs. Thereafter, poly(vinylidene fluoride) (PVDF) thin films doped with different amounts of WO3·H2O NPs (1-15 mass%) have been prepared via a simple solution-casting method to verify the role of the NPs on the enhancement of electroactive β phase crystallization and dielectric properties of WO3·H2O NP-PVDF thin films. The interface between the NPs and the polymer matrix takes a vital role in improving β phase nucleation and dielectric properties of the WO3·H2O NP modified PVDF thin films. Strong electrostatic or ion-dipole interaction between the negatively charged NP surfaces and -CH2 dipoles of the polymer matrix at the interface effectively improves the electroactive β phase nucleation and dielectric properties of the nanocomposite thin films.
- Thakur, Pradip,Kool, Arpan,Bagchi, Biswajoy,Hoque, Nur Amin,Das, Sukhen,Nandy, Papiya
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p. 62819 - 62827
(2015/08/06)
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