scholarly journals Characterization of Copper Complex Nanoparticles synthesized by Plant Polyphenols

2017 ◽  
Author(s):  
Zhiqiang Wang ◽  
Pengfei An

AbstractIn this paper a kind of copper oxide material of copper–polyphenols complex nanoparticles (Cu–P NPs) were synthesized by Cinnamomum pedunculatum leaves extract, which have different morphology and appearance compared with usual copper oxides Cu2O and CuO. For better understanding about this material, the Cu–P NPs were characterized using scanning electron microscopy (SEM), X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). It was found that synthesized Cu–P NPs were amorphous with spherical particles ranged from 80 to 500 nm. XAS data analysis indicated that the synthesized Cu–P NPs has different molecular structure with Cu2O and CuO. It is assumed that the copper ions chelated with polyphenol molecule. The nanoparticles showed a clear anti Escherichia coli activity in this study, and may also be used in fields of semiconductor, ceramic, catalyst, and sensor. This synthesis approach provided a novel route to manufacture copper oxide nanomaterial.

1997 ◽  
Vol 496 ◽  
Author(s):  
Yair Ein-Eli ◽  
W. F. Howard ◽  
Sharon H. Lu ◽  
Sanjeev Mukerjee ◽  
James McBreen ◽  
...  

ABSTRACTA series of electroactive spinel compounds, LiMn2-xCuxO4 (0.1 ≤ x ≤ 0.5) has been studied by crystallographic, spectroscopie and electrochemical methods and by electron-microscopy. These LiMn2-xCuxO4 spinels are nearly identical in structure to cubic LiMn2O4 and successfully undergo reversible Li intercalation. The electrochemical data show slight shifts to higher voltage for the delithiation reaction that normally occurs at 4.1 V in standard Li1−xMn2O4 electrodes (1 ≥ x ≥ 0) corresponding to the oxidation of Mn3+ to Mn4+. The data also show a remarkable reversible electrochemical process at 4.9 V which is attributed to the oxidation of Cu2+ to Cu3+. The inclusion of Cu in the spinel structure enhances the electrochemical stability of these materials upon cycling. The initial capacity of LiMn2-xCuxO4 spinels decreases with increasing x from 130 mAh/g in LiMn2O4 (x=0) to 70 mAh/g in “LiMn1.5Cu0.5O4”(x=0.5). Although the powder X-ray diffraction pattern of “LiMn1.5Cu0.5 O4” shows a single-phase spinel product, neutron diffraction data show a small, but significant quantity of an impurity phase, the composition and structure of which could not be identified. X-ray absorption spectroscopy was used to gather information about the oxidation states of the manganese and copper ions. The composition of the spinel component in the LiMn1.5Cu0.5O4 was determined from X-ray diffraction and XANES data to be Li1.01Mn1.67Cu0.32O4 suggesting, to a best approximation, that the impurity in the sample was a lithium-copper-oxide phase.


2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Daisuke Ogawa ◽  
Ryo Kitaura ◽  
Takeshi Saito ◽  
Shinobu Aoyagi ◽  
Eiji Nishibori ◽  
...  

Thermally fragile tris(η5-cyclopentadienyl)erbium (ErCp3) molecules are encapsulated in single-wall carbon nanotubes (SWCNTs) with high yield. We realized the encapsulation of ErCp3with high filling ratio by using high quality SWCNTs at an optimized temperature under higher vacuum. Structure determination based on high-resolution transmission electron microscope observations together with the image simulations reveals the presence of almost free rotation of each ErCp3molecule in SWCNTs. The encapsulation is also confirmed by X-ray diffraction. Trivalent character of Er ions (i.e., Er3+) is confirmed by X-ray absorption spectrum.


2014 ◽  
Vol 775-776 ◽  
pp. 97-101
Author(s):  
Loanda Raquel Cumba ◽  
U.O. Bicalho ◽  
D.R. Carmo

This paper describes the preparation and complementary characterization of a composite formed from the activation of titanium isopropoxide by phosphoric acid and deionized water (TiP).Techniques such as, X-ray diffraction (XRD), Raman , electronic (UV-vis) and Scanning electron microscopies (SEM) were used for characterization of this new composite formed. In the X-ray diffractogram of TIP was observed four intense peaks. A strong absorption was observed in the region 362-445 nm. The scanning electron microscopy of TiP, shows that the prepared material consists mostly of a cluster of spherical particles with diameters ranging from 2.35 to 2.60 μm.


1998 ◽  
Vol 269-272 ◽  
pp. 473-478 ◽  
Author(s):  
Francsco Cardellini ◽  
Vittoria Contini ◽  
Gregorio D'Agostino ◽  
Adriano Filipponi

2003 ◽  
Vol 802 ◽  
Author(s):  
S. Skanthakumar ◽  
L. Soderholm

ABSTRACTThe effect of Am doping on the physical properties of three superconducting systems (RBa2Cu3O7, Pb2Sr2R1−xCaxCu3O8 and R2−xMxCuO4) have been studied using x-ray diffraction, x-ray absorption spectroscopy (XAS) and magnetic susceptibility experiments. Am is incorporated into all three systems as the tetravalent ion and superconductivity is not observed in any of the resultant compounds. The absence of superconductivity in Pb2Sr2Am0.5Ca0.5Cu3O8 is attributed to the transfer of charge from Am to the Cu-O planes. Systems that cannot incorporate a tetravalent ion, notably AmBa2Cu3O7 and Am2CuO4, do not form. Although Pr1.85Am0.15CuO4 forms with similar structure to Pr1.85Ce0.15CuO4, and Am like Ce is tetravalent, it is not superconducting. We argue that the absence of superconductivity in the Am doped Pr compound it is due to the hybridization of radially-extended f orbitals on the magnetic Am4+ ion with the Cu-O band states.


1989 ◽  
Vol 03 (07) ◽  
pp. 1085-1096 ◽  
Author(s):  
F. STUDER ◽  
R. RETOUX ◽  
C. MARTIN ◽  
C. MICHEL ◽  
B. RAVEAU ◽  
...  

The valence states of cations inside four high T c thallium superconductors have been investigated by X-ray absorption spectroscopy at thallium LIII , LI and copper K-edges. The thallium ions are observed on LIII and LI edges in the Tl(III) valence state (empty 6s levels) in spite of large Tl-O distances in the (a, b) plane of the structure as deduced from X-ray diffraction. The presence of two types of Tl-O distances have been well established on XANES spectra and the F.T. of EXAFS have shown the presence of two very short Tl-O bonds (2.03 Å). The copper K-edges are characterized by the absence of Cu(I) state (3d10 line).


2019 ◽  
Vol 37 (3) ◽  
pp. 347-352
Author(s):  
A. H. Moharram

AbstractCopper oxide and cobalt oxide (Co3O4, CuO) nanocrystals (NCs) have been successfully prepared using microwave irradiation. The obtained powders of the nanocrystals (NCs) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric (TGA) analysis and Fourier-transform infrared spectroscopy. The obtained results confirm the presence of both nanooxides which have been produced during chemical precipitation using microwave irradiation. TEM micrographs have shown that the obtained nanocrystals are characterized by high dispersion and narrow size distribution. The results of X-ray diffraction confirmed those obtained from the transmission electron microscope. Optical absorption analysis indicated the direct band gap for both kinds of the nanocrystals.


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