Abstract
Zinc oxide (ZnO) nanoparticles (NPs) were synthesized by different methods known as Pechini and Sol-Gel. It was observed during the experiments significant differences comparing these methods as: particle size, time applied, crystallinity and chemical residues generated by-products. The NPs were analysed ...
Read More
Zinc oxide (ZnO) nanoparticles (NPs) were synthesized by different methods known as Pechini and Sol-Gel. It was observed during the experiments significant differences comparing these methods as: particle size, time applied, crystallinity and chemical residues generated by-products. The NPs were analysed by X-ray diffraction (XRD), ultraviolet-visible (UV-Vis.) absorption and Raman spectroscopy techniques. X-Ray Difractograms showed peaks corresponding to hexagonal wurtzite crystalline structure. It was observed that NPs obtained by the Pechini showed better homogeneity and crystallinity; these presented average size of 115 nm. The NPs produced by Sol-Gel method showed crystallites with smaller average size of 8 nm. The band gap energy (Eg) obtained using UV-Vis for ZnO NPs synthesized by Pechini was 3.39 eV. Still, the results for Sol-Gel method with 5 and 10 hours of reactions were 3.53 eV and 3.55 eV respectively. Raman data obtained by Pechini and Sol-Gel Methods showed characteristics peaks. The obtained data confirmed the ZnO phase samples and the proportional relationship to the enlargement with the intensity of peaks E2 High ˜ 438 cm -1 , as evidenced by literature. These results lead to the applicability of both NPs in optoelectronic and fluorescent applications.
M. F. R. Fouda; M. A. Wahba;M. F. El-Shahat; M. B. ElKholy; S. A. Mostafa; A. I. Hussien
Abstract
AnchorUniform α-Fe2O3 nanoparticles have been prepared by sol gel method using three different carboxylic acids citric, tartaric and succinic acids as chelating agents. The structure and morphology of α-Fe2O3 samples were characterized using (TGA), (XRD), (TEM), (IR) and diffuse reflectance ...
Read More
AnchorUniform α-Fe2O3 nanoparticles have been prepared by sol gel method using three different carboxylic acids citric, tartaric and succinic acids as chelating agents. The structure and morphology of α-Fe2O3 samples were characterized using (TGA), (XRD), (TEM), (IR) and diffuse reflectance spectroscopy (DRS) techniques. The TEM images revealed that in all cases, the products consisted of 18–25 nm sized particles close to the average crystallite size calculated from XRD data by the Scherrer’s formula. Among the prepared samples, the sample that has the best thermal stability, the smallest particle size and the reddest color is that prepared in presence of tartaric acid. The prepared samples were evaluated as pigments according to the American Society for Testing and Materials (ASTM) standard methods for evaluation of pigments.
