CuO and Co₃O₄Nanoparticles: Synthesis, Characterizations, and Raman Spectroscopy

Abstract

Copper oxide and cobalt oxide (CuO, Co3O4) nanocrystals (NCs) have been successfully prepared in a short time using microwave irradiation without any postannealing treatment. Both kinds of nanocrystals (NCs) have been prepared using copper nitrate and cobalt nitrate as the starting materials and distilled water as the solvent. The resulted powders of nanocrystals (NCs) were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM) measurements. The obtained results confirm the presence of the both of oxides nanopowders produced during chemical precipitation using microwave irradiation. A strong emission under UV excitation is obtained from the prepared CuO and Co3O4nanoparticles. The results show that the nanoparticles have high dispersion and narrow size distribution. The line scans of atomic force microscopy (AFM) images of the nanocrystals (NCs) sprayed on GaAs substrates confirm the results of both X-ray diffraction and transmission electron microscopy. Furthermore, vibrational studies have been carried out using Raman spectroscopic technique. Specific Raman peaks have been observed in the CuO and Co3O4nanostructures, and the full width at half maximum (FWHM) of the peaks indicates a small particle size of the nanocrystals.

Cobalt-Doped Carbon Gels as Electro-Catalysts for the Reduction of CO2 to Hydrocarbons

“…The presence of Co(II) species was also corroborated by Raman (Figure 4). Raman spectra of samples with 4% and 6% of cobalt show four peaks at 672, 607, 510, and 466 cm −1 , which can be well assigned to the presence of Co 3 O 4 nanoparticles [35]. Figure 4 shows two main signals at 1340 and 1580 cm −1 approx.…”

Structural and Luminescent Properties of (Y,Cu)-Codoped Zirconia Nanopowders

“…It was shown that in this case the parameters of EPR signal (g-factor, hyperfine coupling and anisotropy) depend on the structure of complex and the type of ligands. 36,39 The formation of surface complexes or CuO is supported by the appearance of the Raman peak at ∼280 cm −1 (not shown) that could be related to CuO 40 or cuprates. Such transformations of EPR and Raman scattering spectra can be explained by the outward diffusion of Cu atoms from nanocrystal volume to its surface.…”

Atomically Thin Hexagonal Boron Nitride Nanofilm for Cu Protection: The Importance of Film Perfection

“…Additionally, more intense Cu oxide peaks (greenish and reddish regions in the Raman mapping) are observed below the BNNF triangles, along the edges and domain boundaries (see also Figure S3b). [23,24] Thus, the red stripes observed for the fully covered Cu (Figures 1b, c) are due to the oxidation of Cu along the defect-rich lines/regions in the BNNF.…”

“…Additionally, more intense Cu oxide peaks (greenish and reddish regions in the Raman mapping) are observed below the BNNF triangles, along the edges and domain boundaries (see also Figure S3b). [23,24] Thus, the red stripes observed for the fully covered Cu (Figures 1b, c) are due to the oxidation of Cu along the defect-rich lines/regions in the BNNF.XPS spectra (Figure 1g) of a bare Cu substrate and of a BNNF coated substrate (i.e. BNNF grown on solid Cu) after 1 month of air exposure reveal weak satellite peaks of Cu 2p3/2 and Cu 2p1/2, attributed to a thin layer of Cu2O.…”