Photoluminescence profile mapping of Eu(iii) and Tb(III → IV)-embedded in quantum size SnO2 nanoparticles

RSC Advances ◽  
2014 ◽  
Vol 4 (59) ◽  
pp. 31155-31161 ◽  
Author(s):  
Young In Choi ◽  
Youngku Sohn

Eu(iii) and Tb(iv) activators were embedded in quantum size SnO2 nanoparticles by a hydrothermal method and their morphologies, crystal structures and spectroscopic properties were examined by transmission electron microscopy, X-ray diffraction crystallography, UV-visible absorption, and 2D/3D-photoluminescence mapping.

2007 ◽  
Vol 353-358 ◽  
pp. 2163-2166
Author(s):  
Ming Yang ◽  
Guo Qing Zhou ◽  
Jiang Guo Zhao ◽  
Zhan Jun Li

Nanocubes, monodispersed nanocrystals and nanospheres of Au have been prepared by a simple reaction between HAuCl4·4H2O, NaOH and NH2OH·HCl in the presence of gelatin. The role of gelatin and the affection of pH in producing the nanoparticles of Au were discussed. The products were characterized by X-ray powder diffraction, transmission electron microscopy, and UV-visible absorption spectroscopy. The sizes of the monodispersed nanocrystals of Au were estimated by Debye-Scherrer formula according to XRD spectrum.


2012 ◽  
Vol 502 ◽  
pp. 164-168
Author(s):  
Ling Xu ◽  
Han Mei Hu ◽  
Hai Yan Xu

Novel mace-like (wolf-teeth clubs) CdS nanostructures were successfully prepared on a large scale using CdCl2•2.5H2O and NH2CSNH2 as starting materials through a convenient mixed-solvothermal route. The as-synthesized products were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDX), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and UV-visible absorption spectroscopy. The experimental results reveal that the morphology of CdS products was greatly affected by the volume ratio of anhydrous ethanol and distilled water. The possible mechanism for the formation of mace-like CdS nanostructures is simply discussed.


2020 ◽  
Vol 14 (2) ◽  
pp. 161-167
Author(s):  
Patrícia Pimentel ◽  
Jairo Dutra ◽  
Maria Câmara ◽  
Gerbeson Dantas ◽  
Osmar Bagnato ◽  
...  

In this work, we synthesized oxides with perovskite LnFeO3 type structure (where Ln = La, Pr and Nd), aiming their use as ceramic pigments. The as-synthesized powders, prepared by gelatin method, were thermally treated at 600 and 800 ?C to obtain the perovskite phase. The characterization was performed using X-ray diffraction technique, followed by Rietveld refinement, scanning and transmission electron microscopy, spectroscopy in the UV-Visible region and CIE Lab colorimetry. The calcined powders were also used for fabrication of ceramic pieces to evaluate the colour when 2 wt.% of the powders was added into a transparent glaze. The pigments presented shades ranging from pale brown for the powdered samples to yellowish when applied in the glazes.


2010 ◽  
Vol 14 (06) ◽  
pp. 540-546 ◽  
Author(s):  
Lingling Zhang ◽  
Yongtao Lu ◽  
Yukou Du ◽  
Ping Yang ◽  
Xiaomei Wang

Meso-tetrakis(p-sulfonatophenyl)porphyrin (TPPS4) functionalized platinum nanocomposites were synthesized and characterized using ultraviolet-visible absorption spectroscopy (UV-vis), fluorescence spectroscopy (FL), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD) methods. The postulated configuration of TPPS4 functionalized platinum nanocomposite may be described as an antenna system containing a photoreceptive TPPS4 shell and a nanosize platinum core. Fluorescence and photoelectrochemistry studies of both TPPS4 and the platinum nanocomposites showed that efficient electron/energy transfer occurred from the TPPS4 donor to the metallic nanocore acceptor. TPPS4 functionalized platinum nanocomposites are photocatalytic active for water reduction to produce hydrogen. The turnover numbers (TONPt and TONTPPS4) and quantum yield of hydrogen (ϕH2) for the photocatalyst (nPt:nTPPS4= 250) were 44, 11056, and 1.8%, respectively, calculated on the basis of the total amount of H2 evolution for 12 h irradiation.


2012 ◽  
Vol 455-456 ◽  
pp. 549-552
Author(s):  
Kai Cheng Zhang ◽  
Si Ying Zhao

Monodispersed nanotriangles of gold have been prepared by a simple reaction between HAuCl4·4H2O, KOH and NH2OH·HCl in the presence of gelatin. Gelatin played a decisive role as an inhibitor of the direct reaction of NH2OH with AuCl4- and coagulation of the growing gold in producing the triangle. In the absence of gelatin, we can only obtain irregular large gold particles. The products were characterized by X-ray powder diffraction, transmission electron microscopy and UV-visible absorption spectroscopy.


2011 ◽  
Vol 194-196 ◽  
pp. 755-758
Author(s):  
Ming Yang ◽  
Kui Zhou

Bicone-shaped and monodispersed nanoparticles of Cu2S have been prepared by a simple reaction between CuO suspension, NH2OH•HCl and (NH4)2S in the presence of gelatin at 5°C. The products were characterized by X-ray powder diffraction, transmission electron microscopy and UV-visible absorption spectroscopy. The band gaps are estimated to be 1.98 eV and 2.03 eV according to the results of optical measurements of bicone-shaped and monodispersed nanoparticles of Cu2S.


2021 ◽  
pp. 1-13
Author(s):  
Iqbal Wadan ◽  
Haroon Khan ◽  
Kamran Tahir ◽  
Muhammad Khalid Khan ◽  
Barkat Ali Khan

In current work, silver nanoparticles (AgNPs) were prepared by a rapid biogenic technique “Green method” utilizing root extract of Olea ferruginea. The synthesized nanoparticles were characterized for UV visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning electron microscopy (SEM), High Resolution Transmission Electron Microscopy Studies (HRTEM) and biological assays. UV visible absorption spectroscopy confirms the formation of AgNPs by giving Surface Plasmon Resonance (SPR) peak at 430 nm. FTIR study showed occurrence of various functional groups present in root extract of Olea ferruginea. X-ray diffraction analysis determined the crystalline nature of bio-fabricated silver nanoparticles. The elemental composition of green made silver nanoparticles was studied through Energy Dispersive Spectroscopy (EDS) analysis. SEM & HRTEM study revealed the size, shape, surface morphology & dispersion level of molecules. The biologically synthesized AgNPs showed high antimicrobial, antifungal and antioxidant activity. The AgNPs are observed to be an excellent catalyst on reduction of hazardous dyes, which is confirmed by a decrease in absorbance of maximum values.


Author(s):  
R. Gronsky

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.


Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 611
Author(s):  
Celia Marcos ◽  
María de Uribe-Zorita ◽  
Pedro Álvarez-Lloret ◽  
Alaa Adawy ◽  
Patricia Fernández ◽  
...  

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.


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