Insights into the Synthesis Parameters Effects on the Structural, Morphological, and Magnetic Properties of Copper Oxide Nanoparticles

Abstract

The present study aims at the integration of the “oxalic conversion” route into “green chemistry” for the synthesis of copper oxide nanoparticles (CuO-NPs) with controllable structural, morphological, and magnetic properties. Two oxalate-containing precursors (H2C2O4.2H2O and (NH4)2C2O4.H2O) and different volume ratios of a mixed water/glycerol solvent were tested. First, the copper oxalates were synthesized and then subjected to thermal decomposition in air at 400 °C to produce the CuO powders. The purity of the samples was confirmed by X-ray powder diffraction (XRPD), and the crystallite sizes were calculated using the Scherrer method. The transmission electron microscopy (TEM) images revealed oval-shaped CuO-NPs, and the scanning electron microscopy (SEM) showed that morphological features of copper oxalate precursors and their corresponding oxides were affected by the glycerol (V/V) ratio as well as the type of C2O42− starting material. The magnetic properties of CuO-NPs were determined by measuring the temperature-dependent magnetization and the hysteresis curves at 5 and 300 K. The obtained results indicate the simultaneous coexistence of dominant antiferromagnetic and weak ferromagnetic behavior.

Structural and Magnetic Characterization of Ni-Co Mixed Ferrite Nanopowders Synthesized via Coprecipitation and Sol-Gel Methods

“…When comparing the particle sizes (D) obtained from TEM or SEM with the crystallite sizes (D XRD ) calculated using the Scherrer equation, it is observed that the D XRD values are smaller than those of D. This suggests that most of the synthesized nanoparticles consist of a crystalline multidomain structure. These results are consistent with findings in the literature, which generally indicate that particle sizes estimated using the Scherrer equation are smaller than the real sizes observed in TEM or SEM micrographs 49,50 . These discrepancies between D XRD and D values may be attributed to factors such as nanoparticle aggregation, the presence of large particles, and the polydispersity of particle sizes 46,51 .…”

Surface structured silver-copper bimetallic nanoparticles by irradiation of excimer laser pulses to bilayer thin films

“…Also, recently, Cu-Ag NPs with tunable compositions and structures have been synthesized using femtosecond laser reduction in solutions of copper and silver precursor [34]. Magnetic properties of copper oxide NPs have been also reported which can be used in Ag-Cu NPs to provide the magnetic properties in the NPs [35]. Silver-copper thin films with an average diameter of NPs ∼4 nm have been deposited by DC magnetic sputtering under nitrogen gas at different deposition times and their results showed that surface plasmon resonance (SPR) wavelength of the deposited thin film experienced a sharply blue shift by increasing the deposition time from 8 to 24 min [36].…”