Yazar "Altinay, Y." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    A green approach for the preparation of nanostructured zinc oxide: Characterization and promising antibacterial behaviour
    (Elsevier Sci Ltd, 2021) Tasdemir, A.; Aydin, R.; Akkaya, A.; Akman, N.; Altinay, Y.; Cetin, H.; Sahin, B.
    In the present study, nanostructured zinc oxide (ZnO) films have been successfully synthesized using fruit extract of Viburnum opulus L. (VO) on glass slides by successive ionic layer adsorption and reaction (SILAR) procedure. The impact of VO concentrations on the structural, morphological, optical, electrical, and antibacterial attributes of ZnO films has been investigated in detail. The samples' XRD patterns present a hexagonal crystal structure with a preferential orientation along the (002) plane. The crystallite size values of ZnO samples were found to be in the ranges from 14.88 to 9.23 nm. The supplementation of VO to the synthesis solution remarkably affected the surface morphological features of the ZnO films. The optical results demonstrated that band gap energy values of the ZnO films at room temperature were decreased from 3.20 to 3.07 eV as a function of VO content in the bath solution. The films' electrical properties were determined by impedance analysis in the frequency range of 20 Hz -1 MHz. Impedance-frequency measurements showed VO insertion to ZnO thin films cause an increase in impedance value at the low frequencies. Cole-Cole plots with a single semi-circle confirmed the contribution of grain and grain boundary for the electrical conduction process. The agar disk diffusion method was used to test the antibacterial properties of ZnO/VO inserted ZnO and inhibition zones were measured. VO inserted ZnO showed a stronger inhibitory effect on gram-positive bacteria Staphylococcus aureus (ATCC 25923) and gramnegative bacteria Escherichia coli (ATCC 35218) than ampicillin antibiotic used as a control group. In line with the promising bactericidal results of a new generation, VO inserted ZnO, the nanostructured product with this study, it can also be applied in multidrug-resistant clinical isolates obtained from patients.
  • [ N/A ]
    Öğe
    SILAR processing and characterization of bare and graphene oxide (GO) and reduced graphene oxide (rGO)-doped CuO thin films
    (Springer Heidelberg, 2022) Altinay, Y.; Gokoglan, E.; Yener, C.; Unlu, G.; Sahin, B.
    In this research, bare, graphene oxide (GO) and reduced graphene oxide (rGO)-doped nanostructured copper oxide (CuO) thin films have been deposited on soda-lime glass substrates using low-cost and easy solution-based successive ionic layer adsorption and reaction (SILAR) method. The victoriously produced films were characterized to understand the effect of GO and rGO content on the crystalline structure, surface morphology, and optical properties of the CuO samples by different characterization methods. The obtained results showed that GO and rGO doping heavily affected the main physical characteristics of CuO nanostructures. XRD measurements confirmed the sharp, monoclinic CuO phase with the preferred orientation (002) and (112). The estimated crystallite size of samples is changed with GO and rGO doping as 7.63, 8.37, and 8.50 nm for the bare, GO, and rGO-doped CuO films, respectively. FE-SEM and SPM results exhibited that film morphology is influenced by the GO and rGO doping. The FTIR and Raman spectra of CuO have an ordinary stretching vibration mode of the metal-oxide bonds and the presence of GO/rGO led to the change of peaks of this structure. The optical bandgap energy of bare CuO was found to be 1.47 eV and it decreased to 1.32 eV as a result of rGO doping which is good sufficient for solar window applications. The sheet resistance value decreased with the GO doping from 7.87 x 10(9) to 2.72 x 10(9) omega/sq. The obtained results signify that the doping of GO and rGO in CuO thin films are responsible for the regulation of the main physical properties of nanostructured materials as electronic and optoelectronic materials.