Fabrication of Bifunctional SiO2/Europium-Polyoxometalates/Ag Particles and their Luminescence and Catalysis Properties

2013 ◽  
Vol 575-576 ◽  
pp. 216-224
Author(s):  
Jun Wang ◽  
Shao Hua Fan ◽  
Wei Qian Zhao ◽  
Wu Ke Li ◽  
Xue Lian Lu
Keyword(s):  
Main Product ◽  
Catalytic Properties ◽  
Uv Light ◽  
Luminescent Properties ◽  
Silica Spheres ◽  
Hybrid Particles ◽  
Red Emission ◽  
Transmission Electron ◽  
Ag Particles ◽  
Luminescent Spectra

In this paper, Stöber silica particles were decorated with polyethyleneimine and silver nanoparticles and Eu-polyoxometalates were grafted on the surface of polyethyleneimine/silica spheres. The hybrid SiO2/Eu-polyoxometalates/Ag particles were characterized by IR, UVvis, luminescent spectra, scanning electron microscopy, transmission electron microscope, and cyclic voltammetry (CV), respectively. The hybrid particles show the bright red emission under UV light which can be observed by naked eyes. The luminescent properties of particles have been investigated which show that Ag nanoparticles have an influences on the luminescence of europium ions. The electrochemical activities of SiO2/Eu-polyoxometalates/Ag particles have been demonstrated by CV measurement. The catalytic results indicate that the hybrid particles show the catalytic properties in the oxidation of styrene and benzaldehyde is the main product of the reaction.

Nanostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ Particles: Polyol-Mediated Synthesis and Luminescent Properties

2007 ◽  
Vol 7 (2) ◽  
pp. 602-609 ◽  
Author(s):  
Zhenling Wang ◽  
Guangzhi Li ◽  
Zewei Quan ◽  
Deyan Kong ◽  
Xiaoming Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Blue Emission ◽  
Luminescent Properties ◽  
Spherical Particles ◽  
Sem Images ◽  
Blue Emission Band ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
20 Nm

Nano-submicrostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Pb3+ particles were prepared by polyol method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), thermogravimetry-differential thermal analysis (TG-DTA), photoluminescence (PL), cathodoluminescence (CL) spectra and PL lifetimes. The results of XRD indicate that the as-prepared samples are well crystallized with the scheelite structure of CaWO4. The FE-SEM images illustrate that CaWO4 and CaWO4 : Pb2+ and CaWO4 : Tb3+ powders are composed of spherical particles with sizes around 260, 290, and 190 nm respectively, which are the aggregates of smaller nanoparticles around 10–20 nm. Under the UV light or electron beam excitation, the CaWO4 powders exhibits a blue emission band with a maximum at about 440 nm. When the CaWO4 particles are doped with Pb2+, the intensity of luminescence is enhanced to some extent and the luminescence band maximum is red shifted to 460 nm. Tb3+-doped CaWO4 particles show the characteristic emission of Tb3+ 5D4–7FJ (J = 6 – 3) transitions due to an energy transfer from WO42− groups to Pb3+.

Nanostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Tb3+ Particles: Polyol-Mediated Synthesis and Luminescent Properties

2007 ◽  
Vol 7 (2) ◽  
pp. 602-609 ◽  
Author(s):  
Zhenling Wang ◽  
Guangzhi Li ◽  
Zewei Quan ◽  
Deyan Kong ◽  
Xiaoming Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Uv Light ◽  
Blue Emission ◽  
Luminescent Properties ◽  
Spherical Particles ◽  
Sem Images ◽  
Blue Emission Band ◽  
Transmission Electron ◽  
Characteristic Emission ◽  
20 Nm

Nano-submicrostructured CaWO4, CaWO4 : Pb2+ and CaWO4 : Pb3+ particles were prepared by polyol method and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier transform infrared spectra (FT-IR), thermogravimetry-differential thermal analysis (TG-DTA), photoluminescence (PL), cathodoluminescence (CL) spectra and PL lifetimes. The results of XRD indicate that the as-prepared samples are well crystallized with the scheelite structure of CaWO4. The FE-SEM images illustrate that CaWO4 and CaWO4 : Pb2+ and CaWO4 : Tb3+ powders are composed of spherical particles with sizes around 260, 290, and 190 nm respectively, which are the aggregates of smaller nanoparticles around 10–20 nm. Under the UV light or electron beam excitation, the CaWO4 powders exhibits a blue emission band with a maximum at about 440 nm. When the CaWO4 particles are doped with Pb2+, the intensity of luminescence is enhanced to some extent and the luminescence band maximum is red shifted to 460 nm. Tb3+-doped CaWO4 particles show the characteristic emission of Tb3+ 5D4–7FJ (J = 6 – 3) transitions due to an energy transfer from WO42− groups to Pb3+.

Luminescent Properties of Gd2MoO6:Eu3+ Nanophosphor for WLEDs

2021 ◽  
Author(s):  
Yan Chen ◽  
Yuemei Lan ◽  
Dong Wang ◽  
Guoxing Zhang ◽  
Wenlong Peng ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Fluorescence Spectra ◽  
Solvothermal Method ◽  
Luminescent Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron

A series of Gd2-xMoO6:xEu3+(x=0.18-0.38) nanophosphors were synthesized by the solvothermal method. The properties of this nanophosphor were characterized by x-ray diffraction (XRD), transmission electron microscope (TEM), fluorescence spectra and diffuse...

scholarly journals Green Chemical Synthesis of N-Cholyl-L-Cysteine Encapsulated Gold Nanoclusters For Fluorometric Detection of Mercury Ions

2021 ◽  
Author(s):  
Kasthuri Jayapalan ◽  
Sivasamy Arumugam ◽  
Rajendiran Nagappan
Keyword(s):  
Uv Light ◽  
Stokes Shift ◽  
Gold Nanoclusters ◽  
Green Emission ◽  
Fluorescence Analysis ◽  
Cost Effective ◽  
Single Step ◽  
Fluorometric Detection ◽  
Transmission Electron ◽  
Green Chemical Synthesis

Abstract Here we report a simple, single-step, cost-effective, environmentally friendly, and biocompatible approach using sodium salt of N-cholyl-L-cysteine (NaCysC) capped gold nanoclusters (AuNCs) with green emission properties at above the CMC in aqueous medium under UV-light irradiation. The primary and secondary CMC of NaCysC was found to be 4.6 and 10.7 mM respectively using pyrene as fluorescent probe. The synthesized AuNCs exhibit strong emission maxima at 520 nm upon excitation of 375 nm with a large Stokes shift of 145 nm. The surface functionality and morphology of NCs are studied by Fourier transform infrared spectroscopy, dymanic light scattering studies and transmission electron microscopy. The formation of AuNCs was completed within 5 h and exhibit high stability for more than 6 months. The NaCysC templated AuNCs selectively quenches the Hg2+ ions with higher sensitivity in aqueous solution over the other metal ions. The fluorescence analysis of Hg2+ showed a wide linear range from 15 to 120 µM and a detection limit was found to be 15 nM.

scholarly journals Pengaruh Laju Penginjeksian Doping Fluor terhadap Aktivitas Fotokatalis Nanotitania Menggunakan Metode Sol Gel

2020 ◽  
Vol 8 (2) ◽  
pp. 209-218
Author(s):  
Sri Rahayu ◽  
◽  
Posman Manurung ◽  
Roniyus Marjunus ◽  
◽  
...  
Keyword(s):  
Uv Light ◽  
Sol Gel ◽  
Tween 80 ◽  
Ammonium Fluoride ◽  
Sintered Sample ◽  
Titanium Isopropoxide ◽  
Injection Rate ◽  
Particle Sizes ◽  
Fluorine Doping ◽  
Transmission Electron

The titania synthesis of fluorine doping (F-TiO2) was carried out through the sol-gel method. Titanium isopropoxide (TTIP), tween-80, isopropanol and ammonium fluoride (NH4F) as sources of doping fluorine were used as the main ingredients. This research aimed to study the effect of fluorine doping injection rate using injection pumps on F-TiO2 photocatalyst activity. Four fluorine doping samples were prepared with the respective penetration rate of 0.4 ml / 30 minutes; 0.4 ml / 60 minutes; 0.4 ml / 90 minutes and 0.4 ml / 120 minutes. The titania powder was calcined at 450 oC for 5 hours. The sintered sample was tested for photodegradation of remazol yellow under UV light. Physical characteristics were analyzed using transmission electron microscopy (TEM) and Uv-Vis spectrophotometer. The results of the UV-Vis spectrophotometer showed that the particle size of samples with an injection rate of 0.4 ml / 90 minutes showed higher photocatalyst activity with particle sizes of (14 nm ± 4 nm).

scholarly journals Photocatalytic Degradation of Methylene Blue under UV Light Irradiation on Prepared CarbonaceousTiO2

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zatil Amali Che Ramli ◽  
Nilofar Asim ◽  
Wan N. R. W. Isahak ◽  
Zeynab Emdadi ◽  
Norasikin Ahmad-Ludin ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Activated Carbon ◽  
In Situ Polymerization ◽  
Uv Light ◽  
Carbon Composite ◽  
Light Irradiation ◽  
Uv Light Irradiation ◽  
Transmission Electron ◽  
Vis Spectroscopy

This study involves the investigation of altering the photocatalytic activity of TiO2using composite materials. Three different forms of modified TiO2, namely, TiO2/activated carbon (AC), TiO2/carbon (C), and TiO2/PANi, were compared. The TiO2/carbon composite was obtained by pyrolysis of TiO2/PANi prepared by in situ polymerization method, while the TiO2/activated carbon (TiO2/AC) was obtained after treating TiO2/carbon with 1.0 M KOH solution, followed by calcination at a temperature of 450°C. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR), thermogravimetric analysis (TG-DTA), Brunauer-Emmet-Teller (BET), and UV-Vis spectroscopy were used to characterize and evaluate the prepared samples. The specific surface area was determined to be in the following order: TiO2/AC > TiO2/C > TiO2/PANi > TiO2(179 > 134 > 54 > 9 m2 g−1). The evaluation of photocatalytic performance for the degradation of methylene blue under UV light irradiation was also of the same order, with 98 > 84.7 > 69% conversion rate, which is likely to be attributed to the porosity and synergistic effect in the prepared samples.

A new luminescent host material K3GdB6O12: synthesis, crystal structure and luminescent properties activated by Sm3+

2018 ◽  
Vol 233 (6) ◽  
pp. 411-419 ◽  
Author(s):  
Dan Zhao ◽  
Cong-Kui Nie ◽  
Ye Tian ◽  
Bao-Zhong Liu ◽  
Yun-Chang Fan ◽  
...  
Keyword(s):  
Solid State ◽  
Uv Light ◽  
Three Dimensional ◽  
Visual Display ◽  
Luminescent Properties ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Promising Candidate ◽  
Conventional Solid State Reaction ◽  
Host Matrix

Abstract A new borate compound K3GdB6O12 has been prepared using a high temperature flux method and structurally characterized by single crystal X-ray diffraction analysis. The structure can be described as a three-dimensional framework that is composed of [B5O10]5− groups, K+ ions and Gd3+ ions. In this structure, one crystallographic distinct site is mixed occupied by K and Gd atoms at the molar ratio of 1:1. Furthermore, Sm3+ ion was used as the activator to test primary of K3GdB6O12 to be used as a luminescent host matrix. A series of phosphors K3Gd1−xB6O12:xSm3+ were synthesized by conventional solid-state reaction. The photoluminescence properties and concentration quenching of the prepared phosphors were investigated. The results show that K3Gd1−xB6O12:xSm3+ can be efficiently excited by near-UV light. K3Gd1−xB6O12:xSm3+ might be a promising candidate for visual display and solid-state lighting as an orange emission phosphor.

scholarly journals Surface Study of CuO Nanopetals by Advanced Nanocharacterization Techniques with Enhanced Optical and Catalytic Properties

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1298 ◽  
Author(s):  
Muhammad Arif Khan ◽  
Nafarizal Nayan ◽  
Shadiullah Shadiullah ◽  
Mohd Khairul Ahmad ◽  
Chin Fhong Soon
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Average Length ◽  
Tem Analysis ◽  
X Ray ◽  
Surface Study ◽  
Transmission Electron ◽  
One Step ◽  
Controlled Morphology ◽  
Xrd Patterns

In the present work, a facile one-step hydrothermal synthesis of well-defined stabilized CuO nanopetals and its surface study by advanced nanocharacterization techniques for enhanced optical and catalytic properties has been investigated. Characterization by Transmission electron microscopy (TEM) analysis confirmed existence of high crystalline CuO nanopetals with average length and diameter of 1611.96 nm and 650.50 nm, respectively. The nanopetals are monodispersed with a large surface area, controlled morphology, and demonstrate the nanocrystalline nature with a monoclinic structure. The phase purity of the as-synthesized sample was confirmed by Raman spectroscopy and X-ray diffraction (XRD) patterns. A significantly wide absorption up to 800 nm and increased band gap were observed in CuO nanopetals. The valance band (VB) and conduction band (CB) positions at CuO surface are measured to be of +0.7 and −1.03 eV, respectively, using X-ray photoelectron spectroscopy (XPS), which would be very promising for efficient catalytic properties. Furthermore, the obtained CuO nanopetals in the presence of hydrogen peroxide ( H 2 O 2 ) achieved excellent catalytic activities for degradation of methylene blue (MB) under dark, with degradation rate > 99% after 90 min, which is significantly higher than reported in the literature. The enhanced catalytic activity was referred to the controlled morphology of monodispersed CuO nanopetals, co-operative role of H 2 O 2 and energy band structure. This work contributes to a new approach for extensive application opportunities in environmental improvement.

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