Size-and phase-dependent structure of copper(<scp>ii</scp>) oxide nanoparticles

Ahmed, Alauddin; Elvati, Paolo; Violi, Angela

doi:10.1039/c5ra04276c

Cited by 42 publications

(30 citation statements)

References 69 publications

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“…This phenomenon can be explained due to the low melting temperature of the oxide compounds containing copper. 28 In these compounds, the copper ions with high mobility easily diffuse to form larger crystallites as well as grains.…”

Section: Resultsmentioning

confidence: 99%

Cation distribution in CuFe2O4 nanoparticles: Effects of Ni doping on magnetic properties

Thanh

Loan

Anh

et al. 2016

Journal of Applied Physics

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The Cu1−xNixFe2O4 nanoparticles (with x = 0, 0.3, 0.5, 0.7, and 1) were synthesized by using spray co-precipitation method at annealing temperature Ta = 900 °C in air for 5 h. The crystal structure, microstructure, oxidation state, and magnetic properties of the samples were characterized by using X-ray diffraction, synchrotron X-ray diffraction, scanning electron microscopy, X-ray absorption spectroscopy, and vibrating sample magnetometer. It was shown that all the samples have cubic structure. Lattice constant and grain size decrease, while the Curie temperature TC increases with increasing of Ni2+ content. A small amount of Fe2+ was found in all the samples. Cation distribution was determined by using a combination of magnetization measurements, extended X-ray absorption fine structure analysis, and Rietveld refinement from synchrotron X-ray diffraction data. It was indicated that Ni2+ ions occupy in octahedral site only, while Cu2+ ions distribute in both tetrahedral and octahedral sites. The variation of magnetic parameters is discussed based on Ni2+ concentration, grain size, the cation distribution, surface effect, and the presence of Fe2+ ion in the samples.

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Section: Resultsmentioning

confidence: 99%

Cation distribution in CuFe2O4 nanoparticles: Effects of Ni doping on magnetic properties

Thanh

Loan

Anh

et al. 2016

Journal of Applied Physics

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“…6) The average crystallite size is found to be 27.2 nm with size ranging from 15 to 48 nm. The X-ray study indicate that the resultant copper oxide nanoparticles are crystalline and identical to monoclinic structure [34]. Scanning electron microscope (SEM) analysis: The scanning electron microscope showed particles were spherical in shape, ranged 20-35 nm (Fig.…”

Section: X-ray Diffraction Analysismentioning

confidence: 99%

Optimization Properties and Characterization of Green Synthesis of Copper Oxide Nanoparticles Using Aqueous Extract of Cordia myxa L. Leaves

Thamer¹,

Muftin²,

Al-Rubae³

2018

Asian J. Chem.

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Copper oxide nanoparticles (CuONPs) were green synthesized using aqueous extract of Cordia myxa L. leaves as reducing and capping agent. The synthesized nanoparticles were characterized by UV-visible spectrophotometer, FTIR, X-ray diffraction, scanning electron microscope and atomic force microscope. The prepared copper oxide nanoparticles showed surface plasmon resonance centered at 400 nm. The optimized condition for the synthesis of copper nanoparticles revealed that the aqueous extract of Cordia myxa L. leaves:copper sulfate ratio was 1:3, pH was 9 and copper sulfate concentration was 40 mM. FTIR results showed that stabilization and formation of CuONPs were due to phenolic groups and amines in plant extract. The XRD pattern showed that the particles are monoclinic in nature. The crystalline morphology and size of the nanoparticles were determined by scanning electron microscope. Presence of elemental copper was revealed by EDX analysis. Size range was from 20 to 106.81 nm was determined by atomic force microscope.

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“…Quantification of different Cu phases derived by LCF of XANES (Fig.8) recorded for in situ CuCl 2 hydrolysis under moist argon Fourier-transformed in situ EXAFS spectra at Cu K edge during CuCl 2 hydrolysis are surrounded by three oxygen ions and one Cl ion at distances of 1.94 Å and 2.25 Å, respectively[25], and in CuO structure, Cu cations are surrounded by four oxygen ions at a distance of 1.94 Å[43].The Cu-Cu distance in Cu 2 OCl 2 and CuO phases is around 3 Å. The local structure' bond length R, coordination number N and distortion factor around Cu atoms were obtained as a result of the best fitting and are given in Table 5.…”

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confidence: 99%

Cu–Cl Thermochemical Water Splitting Cycle: Probing Temperature-Dependent CuCl2 Hydrolysis and Thermolysis Reaction Using In Situ XAS

Singh

Pai

Banerjee

et al. 2021

J Therm Anal Calorim

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Recently, we reported detailed investigations on a hydrolysis step of Cu-Cl thermochemical cycle (Singh et al. in Int J Energy Res 44:2845-2863 where we demonstrated CuCl 2 hydrolysis using a fixed-bed reactor under optimized conditions. Thermolysis of CuCl 2 and oxide formation are associated hindrances in achieving 100% phase-pure hydrolysis product, Cu 2 OCl 2 . With an objective to understand the thermolysis and hydrolysis processes at molecular level, both these reactions were investigated independently in the present study using in situ XAS as a probe. The progress of both the reactions was recorded from RT to 400 °C by monitoring temperature-dependent evolution of Cu species using Cu K-edge XAS measurements at BL-09, Indus-2 SRS, RRCAT, Indore, India. XAS results are also corroborated with ex situ analysis by XRD and TG of samples containing various compositions of CuCl 2 mixed with boron nitride (pellets employed for XAS). Besides LCF, hydrolysis product Cu 2 OCl 2 yield was further supported by chemical titrations. EXAFS revealed that with increasing temperature, coordination of Cu atoms in reactant CuCl 2 progressively decreased during thermolysis. For hydrolysis process, coordination of Cu atoms in Cu-Cu, Cu-O and Cu-Cl linkages approached towards that of Cu 2 OCl 2 and CuO. CuCl 2 diminished and transformed into CuCl (88 mass%) at 350 °C during thermolysis and ~ 60 mass% of Cu 2 OCl 2 and 40 mass% of CuO during hydrolysis reaction. Based on in situ investigations in the present study, the most probable reactions taking place during CuCl 2 hydrolysis at different temperatures are proposed for S/Cu of 14.6.

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Size-and phase-dependent structure of copper(ii) oxide nanoparticles

Abstract: Core (3 nm diameter) and outer surface layer (0.5 nm width) of a CuO nanoparticle of 4 nm in diameter.

Cited by 42 publications

References 69 publications

Cation distribution in CuFe2O4 nanoparticles: Effects of Ni doping on magnetic properties

Cation distribution in CuFe2O4 nanoparticles: Effects of Ni doping on magnetic properties

Optimization Properties and Characterization of Green Synthesis of Copper Oxide Nanoparticles Using Aqueous Extract of Cordia myxa L. Leaves

Cu–Cl Thermochemical Water Splitting Cycle: Probing Temperature-Dependent CuCl2 Hydrolysis and Thermolysis Reaction Using In Situ XAS

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