Yazar "Akkaya, A." seçeneğine göre listele
Listeleniyor 1 - 6 / 6
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe The effect of thymus syriacus plant extract on the main physical and antibacterial activities of ZnO nanoparticles synthesized by SILAR method(Elsevier, 2022) Sahin, B.; Aydin, R.; Soylu, Soner; Turkmen, M.; Kara, M.; Akkaya, A.; Cetin, H.This study aimed to determine the main physical properties of green synthesized ZnO nanoparticles (ZnO-NPs) using Thymus syriacus plant extract and their antibacterial activities against eight different Gram-positive and Gram-negative plant bacterial disease agents. The surface morphological, structural, optical and electrical attributes of the ZnO films were analyzed by various types of characterization techniques. The authors have observed that the microstructural and surface morphological properties considerably changed by using T. syriacus plant extract. UV-Vis. analysis showed that the bandgap values are increased from 3.17 to 3.28 eV with the T. syriacus content in the growth solution. Impedance measurements presented an increase of the semicircle diameters with the increase % of T. syriacus. The antibacterial effectiveness of ZnO-NPs was evaluated against plant pathogenic bacterial species by using the agar disc diffusion method. Established on inhibition zone diameter values, ZnO-NPs displayed varying levels of antibacterial activities against all bacterial species tested. Gram-positive bacterial species were found more sensitive than Gram-negative species. In comparison, the highest antibacterial activity was displayed against Clavibacter michiganensis subsp. michiganensis and Bacillus subtilis subsp. subtilis, the lowest antibacterial activity was recorded for Pseudomonas corrugata. The present research findings suggest that the green synthesized ZnO-NPs have a prospective to be used as optoelectronic materials and antibacterial agents against plant pathogenic bacterial disease.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.Öğe Light-weight and flexible Ni-doped CuO (Ni:CuO) thin films grown using the cost-effective SILAR method for future technological requests(Springer, 2022) Aydin, R.; Akkaya, A.; Sahin, B.Products based on nanostructured flexible thin films, which are anticipated to make their way into our lifetimes in the near future. Therefore, nanostructured metal-oxide thin-film materials grown on flexible substrates are anticipated to meet emerging technological requests. In this article, we present a promising light-weight and flexible thin-film material using un-doped and Ni-doped CuO samples. Ni:CuO flexible thin-film materials were fabricated by using the cost-effective SILAR method on cellulose acetate substrates and the effects of both Ni doping and bending on the change in electrical and optoelectronic performances were investigated. It is observed that Ni doping has a great impact on the main physical properties of flexible CuO samples. The optical bandgap value of the un-doped CuO film improves with increasing Ni ratio in the growth bath. Also, sheet resistance values of the un-doped and Ni:CuO samples are a little affected due to bending of samples for bending radius similar to 20 mm. These flexible all solution-processed nanostructured CuO samples are promising candidates for use in future optoelectronic applications.Öğe Production of p-CuO/n-ZnO:Co nanocomposite heterostructure thin films: An optoelectronic study(Elsevier Sci Ltd, 2023) Kahveci, O.; Akkaya, A.; Yucel, E.; Aydin, R.; Sahin, B.The p-n junction is the principal mode of optoelectronic semiconductor material. At present, we submit a solution-based attempt at the synthesis of nanostructured p-type CuO and n-type ZnO nanocomposite (NC) heterostructure films. Bare and Cobalt (Co)-doped CuO-ZnO NC films have been produced on glass slides using the SILAR (Successive Ionic Layer Adsorption and Reaction) method. The influence of Co-doping concentration on the physical characteristics of CuO-ZnO NC heterostructure films was investigated. XRD spectrums indicated the phase and structural purity of solution-based synthesized CuO-ZnO NC samples. The surface topographical, as well as optical and electrical properties of heterostructure films were, also investigated. While the bare CuO-ZnO NC film has a-38% transmission near 1000 nm wavelength region, the 2.0% Co-doped CuO-ZnO NC film has-31% of optical transmission. The sheet resistance value of the grown 2.0% Co:CuO-ZnO NC sample is almost 13 times lower than that of the bare CuO-ZnO NC sample at 400 K temperature. As a consequence, our attempt ensures a novel strategy for the production and performance optimization of CuO-ZnO NC hetero-structures in the implementation of optoelectronics.Öğe Solution-processed nanostructured ZnO/CuO composite films and improvement its physical properties by lustrous transition metal silver doping(Springer, 2020) Akkaya, A.; Sahin, B.; Aydin, R.; cetin, H.; Ayyildiz, E.This paper has reported the fabrication and characterization of pristine, and silver (Ag)-doped nanostructured ZnO/CuO composite thin films that have not been previously reported. The thin films were synthesized by the successive ionic layer adsorption and reaction (SILAR) technique. The morphological, crystalline structure, optical and electrical characterizations of the films have been achieved utilizing scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectrum (FTIR) analysis, ultraviolet-visible (UV-Vis) spectrophotometry and the four-point probe measurements. Particle sizes of pristine and Ag-doped ZnO/CuO thin films were found to vary from 32 to 58 nm. Crystallite size was changed from 16.40 to 18.90 nm with changing Ag dopant in the ZnO/CuO composite film. FTIR spectra that have the absorption peaks at similar to 725 and similar to 510 cm(-1) referred to the stretching vibration of Zn-O and Cu-O bonds during the synthesis of ZnO/CuO nanofilms. The bandgap values of ZnO/CuO composite films increased from 2.05 to 2.36 eV as Ag content increased from 0 to 2 M%. The activation energies of the samples were obtained from the Arrhenius plots of sigma versus 1/T. The multiple activation process was observed. It was noteworthy that Ag-doping results in a significant difference in conductivity at all temperature values.Öğe Synthesis of Al and In dual-doped CuO nanostructures via SILAR method: Structural, optical and electrical properties(Elsevier, 2023) Kahveci, O.; Akkaya, A.; Aydin, R.; Sahin, B.; Ayyildiz, E.In this article, we investigated the doping characteristics of Al-doped CuO (ACO), and Al/In co-doped CuO (AICO) thin films, which were synthesized on glass substrates, via the solution-based successive ionic layer adsorption and reaction (SILAR) technique. The surface morphological, chemical composition, structural, optical, and electrical properties of the nanocrystalline films were characterized by Field Emission Scanning Electron Microscopy (FE-SEM), Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier-transform Infrared Spectroscopy (FTIR), Ultraviolet-visible (UV-vis.) spectrophotometry, and Transmission Line Method (TLM), respectively. Surface morphology studies exhibited that a decrease in the films' thickness caused an increment in the optical transmittance. XRD patterns displayed that the obtained samples were polycrystalline and crystallized in a bare CuO monoclinic structure. FTIR studies of the CuO samples displayed that Al and In codoping influenced the forms and the violence of the absorption bands. The optical bandgap energy of bare CuO was determined to increase from 1.45 to 1.78 eV as a result of the co-doping. The substitution of In displayed in the irregularity of the morphology, owing to its wide ionic radius, which caused an increase in band gap energy and a decrease in resistance. The co-doping of Al and In is hence anticipated to ensure an extensive range of physical and optical properties of nanostructured metal oxide samples for a variety of technological applications.
