Three new homobinuclear nanosized supramolecular copper coordination polymers are hydrothermally synthesized by self-assembly reaction of L-tyrosine (Tyr), terephthalic acid (H2bdc), pyromellitic acid (H4btec) and benzimidazole (Hbzim) with copper chloride salt to generate with formula [[Cu2(tyr)2(bzim)2(Cl)2(H2O)2]]n 1, [[Cu2(bdc)2(bzim)2(H2O)6].3H2O]n 2 and [Cu2(H2btec)(bzim)(H2O)6].2H2O]n 3, which have been investigated by elemental analysis, molar conductivity and magnetic measurements, FT-IR and UV-Vis spectroscopy, (TGA/DTA) thermal analysis and X-ray powder diffraction(XRPD) analysis as well as MM2 theoretical calculations. The magnetic moment and electronic spectra of the complexes are certainly indicating the octahedral geometries. Thermal analysis of the complexes confirms the suggested structures and thermal stability. The results of the XRPD analysis and the average nanosized values of the complexes have nanosized supramolecular polymers in the triclinic system. The MM2 theoretical calculations are supported by the proposed structures.
A powder of titanium oxide nanoparticles (TiO2 NPs) was synthesized in this study by anodizing in 0.7 M HClO4 and then annealing in N2 at 450 °C for 3 h to produce TiO2 NPs-N2 powder as a catalyst. These TiO2 NPs-N2 nanoparticles were then encrusted with Au nanoparticles utilizing the photodeposition procedure with tetrachloroauric acid (HAuCl4) and isopropanol as sacrificial donors. With a surface area of 121 m2g−1, the Au NPs/TiO2 NPs-N2 powder catalyst has a high surface area, according to the Barrett–Joyner–Halenda technique. According to X-ray diffraction (XRD) analysis, TiO2 NPs-N2 contained uniformly integrated Au nanoparticles with an average crystallite size of about 26.8 nm. The XRD patterns showed that the prepared Au NPs/TiO2 NPs-N2 were crystallites and nano-sized. The transmission electron microscopy image revealed the spherical shape of the nanoparticles and their tendency for agglomeration. Utilizing the cyclic voltammetry, the electrochemical properties of the catalyst TiO2 NPs powders in a basic glucose solution were investigated. The electrocatalytic activity and stability of the loaded Au NPs/TiO2 NPs-N2 powder on the working electrode for the electrocatalytic oxidation of glucose were astonishingly high. The Au NPs/TiO2 NPs-N2 catalyst demonstrated electrocatalytic characteristics that were superior to a commercially available polycrystalline gold electrode in the application involving glucose alkaline fuel cells.
This paper deals with the preparation of silver/mordenite nanocomposite using aqueous propolis extract along with different concentrations of silver nitrate. The study of the prepared samples' structural properties gave two possibilities for the nanocomposite formation process, and this was confirmed by the UV-visible absorption spectrum and the energy-dispersive X-ray spectroscopy. Unexpectedly, the decrease in the size of these nanocomposites (14-21 nm) showed a non-linear behavior with increasing silver nitrate concentration because of the presence of propolis during urbanization, and this was explained using the results of the transmission electron microscopy images and X-ray diffraction. The Ag/mordenite nanocomposites showed the effective ability to eliminate the two types of bacteria (Gram-positive [Staphylococcus aureus] and Gram-negative [Escherichia Coli]). As well, these nanocomposites demonstrated with simple experiments the removal efficiency of some dyes pollutants (such as methylene blue, methyl orange, malachite green, indigo, and Congo red) from aqueous solutions. These results were explained in this article.
Germanium (Ge) thin films have been deposited onto the glass substrates by the vacuum evaporation technique. The effect of annealing temperature on the structural and optical properties of the germanium thin films was investigated. The structural and optical properties of thin films were characterized by XRD, SEM, and UV-Vis techniques. XRD results showed that the structure of the deposited thin films changed from amorphous phase for the films, which deposited at room temperature, to crystalline phase for the films, which deposited at high temperature. Optimum temperature to obtain a good crystalline structure was 525 ∘ C. The SEM image also showed that the crystallization of the thin films is increased with increasing of annealing temperature. Transmittance and reflectance spectral were used to calculate the absorption coefficient. Two absorption edges in two spectral regions were distinguished according to direct and indirect electron transitions. Energy band gap was calculated by using the Tauc relationship for both direct and indirect electron transitions. The average value of was equal to 0.79 eV and 0.61 eV for direct and indirect transitions, respectively.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.