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 Co₃O₄ nanoparticles. 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 Co₃O₄ nanostructures, and the full width at half maximum (FWHM) of the peaks indicates a small particle size of the nanocrystals.

The functionalized polyvinyl alcohol (PVA) based nanocomposites thick films of 80 μm containing 1–3 wt% zinc oxide (ZnO) nanoparticles (NPs) were studied. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy were utilized for studying the structural parameters and formed chemical bonds of the synthesized PVA-ZnO films. In addition, extensive characterization has been done on their linear and nonlinear optical properties. The structural analysis of the PVA-ZnO nanocomposites revealed the formation of a wurtzite hexagonal ZnO phase embedded inside the monoclinic PVA phase. The interaction between Zn–O, and functional groups of the PVA as well as the molecular vibration exhibited in the PVA-ZnO nanocomposites were confirmed by the Raman and FTIR spectroscopy and revealed that the PVA-ZnO is a hybrid nanocomposite. The incorporated ZnO NPs ratios slightly affect the PVA films' structure, meanwhile, exhibited a detectable change in the linear/nonlinear optical properties of PVA. For example, as ZnO concentration increased from 1 wt% to 3 wt%, the direct/indirect optical band gap of PVA slightly decreased from 5.1/4.93 eV to 4.45/4.89 eV, respectively. Other optical characteristics, such as optical conductivity, dielectric constants, absorption coefficient, refractive index, etc., were evaluated. All observed optical properties versus energy/wavelength display a distinct pulse at 1.4 eV/850 nm which corresponds to the difference between the direct and indirect optical band gaps. It is expected that PVA-ZnO hybrid nanocomposites have become appropriate for implementation in numerous electronic applications due to their improved optical characteristics.

Different zinc oxide (ZnO) morphologies were synthesized via a thermal evaporation-like technique without a catalyst introduction. The morphology of ZnO has been controlled by varying the evaporation pressure of ambient air. X-ray diffractometer and field emission scanning electron microscope were used for crystallinity and morphology investigation, respectively. The X-ray data confirmed the purity and crystallinity of the as-prepared ZnO structure. A variation of the pressure led to different morphologies of ZnO nanostructure such as nanocombs and nanorods. The influence of these different morphologies on the photocatalytic activity was performed on a water wasted methylene blue. The results showed the geometry of one-dimensional nanostructures deposited at different pressures strongly controls the photocatalytic activity of ZnO. The most suitable photocatalytic performance was recorded for ZnO deposited at 0.15 Torr, which showed one-side nanocombs of long nails.