Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Subject: search.filters.subject.Zinc oxide

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  • Article
    Citation - WoS: 103
    Citation - Scopus: 113
    Preparation and Characterizations of Tio2/Zno Nanohybrid and Its Application in Photocatalytic Degradation of Tetracycline in Wastewater
    (Elsevier, 2023) Zeinali Heris, Saeed; Etemadi, Martin; Mousavi, Seyed Borhan; Mohammadpourfard, Mousa; Ramavandi, Bahman
    The photodegradation of tetracycline antibiotics (TC) in an aqueous solution, using the TiO2 nanoparticles, ZnO microparticles, and TiO2/ZnO composite under the UV lamp in a continuous reactor, was performed. The effects of different parameters, such as the initial TC concentration, medium pH, ratio of each photocatalyst, and the flow rate were comprehensively studied. SEM, EDX, and XRD characterization techniques were employed to study the morphology and structure features of the prepared composite. The results revealed that a more significant amount of TC is not easily removed from wastewater. Furthermore, by increasing the pH of the medium to 11, the efficiency of TC degradation was increased, while the amount of removal remained stable at higher pH values. As the flow rate increased up to 190 mL/min, the removal efficiency increased; however, at higher flow rates, lower efficiency was obtained. Moreover, using multivariate analysis and response surface methodology (RSM), a model for removing TC and the effect of experimental parameters on removal efficiency was proposed. The optimal conditions using the RSM method were found to be the reduction efficiency of 78.94 % in pH = 11 (flow rate of 132 mL/min, and TiO2 concentration of 323 mg) and reduction efficiency of 75.89% in pH = 9 (flow rate of 143.19 mL/min and TiO2 concentration of 312.73 mg). © 2023 Elsevier B.V.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 26
    Flexible Metal/Semiconductor Type Photodetectors Based on Manganese Doped Zno Nanorods
    (Elsevier, 2023) Karagöz, Emine; Altaf, Çiğdem Tuç; Yaman, Ecenaz; Yıldırım, İpek Deniz; Erdem, Emre; Çelebi, Cem; Fidan, Mehmet; Sankir, Mehmet; Demirci Sankir, Nurdan
    High-performance flexible photodetectors are one of the most interesting research areas due to their great possibilities for a variety of applications such as portable and wearable optoelectronics. This study verifies the performance of flexible metal/semiconductor/metal-type photodetector based on pristine and manganese doped ZnO nanorods (ZnO-NRs) prepared in two different concentrations of zinc precursors and manganese dopant at low temperatures. The photodetectors having ZnO-NRs with high aspect ratios were investigated by various material characterization techniques such as electron paramagnetic resonance and photoluminescence spectroscopy to confirm the relationship between defect concentrations and photodetector performance parameters. It has been calculated that the detectivity (D*) and responsivity (R) of the ZnO nanorod-based photodetectors increased 20 and 18 folds, respectively by increasing the concentration of zinc precursor. Besides the D* and R values of the photodetectors, prepared by the 16.5 mM zinc precursor, increased 18 and 4.5-fold, respectively, after manganese doping. We confirmed that even a very low concentration of zinc precursor could produce a photodetector with high performance in photo-response characteristics, flexibility, and stability against 10,000 cycles of convex/concave bending.(c) 2023 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 9
    Citation - Scopus: 9
    Zno Nanostructures for Photocatalytic Degradation of Methylene Blue: Effect of Different Anodization Parameters
    (Springer, 2022) Öksüz, Ahmet Emrecan; Yurddaşkal, Metin; Kartal, Uğur; Dikici, Tuncay; Erol, Mustafa
    In this paper, the photocatalytic activity of ZnO nanostructures formed by anodization method with different parameters was investigated. The synthesis of ZnO nanostructures with different morphology by varying anodic oxidation parameters containing electrolytes, molarity, voltage, and duration was analyzed. ZnO nanostructures were prepared through different parameters consisting of six samples. The produced ZnO nanostructures were investigated by using X-ray diffraction, scanning electron microscopy, diffuse reflectance spectroscopy, and UV-Vis spectrophotometer. It was found that the morphology of ZnO structures was formed as nanorods, needle-like, flower-like, heterogeneous, and homogeneous of mixed structures. ZnO nanostructures were identified by matching X-Ray diffraction peaks due to the international center for diffraction data database. Experiments on photocatalytic degradation of methylene blue demonstrated that the photocatalytic activity of ZnO samples. The best photocatalytic performance was observed by the sample anodized for an hour in 0.05 M of KHCO3 electrolytes with 40 V electrical potential. It was observed that the removal of methylene blue increased 3 times (photocatalytic degradation efficiency similar to 31% for methylene blue vs similar to 90% by the best sample) thanks to the obtained ZnO nanostructured photocatalysts. The results showed that an increment of the voltage has a significant effect on the photocatalytic activity of ZnO while keeping other parameters including molarity, time, and electrolyte type constant.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 4
    Photocatalytic and Optical Properties of Zinc Oxide Structures Prepared at Different Urea Concentrations
    (Serban Solacolu Foundation, 2020) Uysal, Berk; Şen, Selin; Top, Ayben
    In this study, ZnO samples were synthesized using zinc acetate and urea with a method containing sonication, sol-gel transition and calcination steps. Urea to zinc acetate mole ratio values were changed as 0, 0.5, 1, and 2 and corresponding calcined samples were denoted as UZ-0, UZ-0.5, UZ-1, and UZ-2, respectively. Scanning electron microscopy (SEM) images indicated globular and rod-like structures. Aspect ratios of the nanorods increased as urea to zinc acetate ratio increased from 0 to 1 whereas nanoparticles with sizes of 70 +/- 20 nm were observed for UZ-2 sample. Brunauer, Emmett and Teller (BET) surface area values of the samples varied between 9 and 25 m(2)/g and increased as initial urea amount increased. Band gap energies of the samples ranged between 3.24 and 3.29 eV. Four major peaks at about 400, 420, 480 and 530 nm with different intensities were observed in the photoluminescence (PL) spectra of the samples. All the samples removed rhodamine B by both adsorption and photodegradation. The highest visible light induced photodegradation rate was exhibited by UZ-2 sample having the highest surface area and it is attributed to superior charge separation properties of this sample under visible light.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Degradation Behaviour of Ti-12nb Alloy Coated With Zno/Tin Double Layer
    (Elsevier, 2021) Çaha, İhsan; Alves, A. C.; Affonco, L. J.; da Silva, J. H. D.; Rodrigues, I. R.; Grandini, C. R.; Rocha, L. A.; Pinto, Ana Maria Pires; Lisboa Filho, P. N.; Toptan, Fatih
    Ti and its alloys have attracted attention for biomedical applications, but their low tribocorrosion resistance, lack of bioactivity and antimicrobial properties are still major clinical concerns. In this study a ZnO coating, intended to act as an antibacterial agent, was deposited on a Ti-12Nb alloy, which was previously coated with a TiN hard coating, for improving tribocormsion resistance. The idea behind is the proof-of -concept that ZnO is able to provide interesting tribological properties to the surface, thus inspiring new ZnO-containing surfaces that can combine antimicrobial properties and tribocormsion resistance. Thus, the corrosion behaviour was studied by open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization tests in phosphate buffered solution at body temperature. The tribocormsion behaviour was carried out at open circuit potential under 0.5 N of normal load, 1 Hz frequency, during 3600 s sliding in phosphate buffered solution at body temperature. The results indicated that duplex coating sample showed better corrosion resistance and drastically better tribocorrosion resistance compared to uncoated and single TiN coating samples.
  • Article
    Citation - WoS: 4
    Citation - Scopus: 4
    Optical and Photocatalytic Properties of Zno and Zns Structures Formed as Controlled Calcination Products of L-Cysteine Assisted Aqueous Precipitation
    (Elsevier, 2020) Şen, Selin; Top, Ayben
    ZnO and ZnS structures were obtained by the calcination of the aqueous precipitation products of Zn(NO3)2, NaOH and L-cysteine (Cys). Initial Cys:Zn molar ratios were changed as 0.1:1, 0.5:1, 1:1 and 1.5:1. All the precursors were transformed into ZnO upon calcination at 700 °C. ZnS structures were obtained by calcining the precursors prepared at the Cys:Zn ratios of 1 and 1.5 at 350 °C. In addition to changing chemical composition of the precipitation products, calcination temperature and initial Cys:Zn ratio also affected morphology, surface area, photoluminescence and photocatalytic properties of the final products. Free exciton energy values of the ZnO samples were observed to be between 3.29 eV and 3.35 eV. PL spectra of the ZnO samples indicated blue and green emission centers. Zinc interstitials (Zni), revealed by the blue emissions in the PL spectra were also confirmed by Auger Zn L3M4.5M4.5 spectra. The samples calcined at 350 °C removed rhodamine B mainly by adsorption. All the samples calcined at 700 °C successfully degraded the dye under UV light. Among the samples calcined at 700 °C, ZnO sample prepared at Cys:Zn = 0.5, which has the highest surface area and unique photoluminescence spectrum exhibited the fastest photodegradation rate. © 2020 Elsevier Ltd
  • Article
    Citation - WoS: 10
    Citation - Scopus: 10
    The Comparison of Transient Photocurrent Spectroscopy Measurements of Pulsed Electron Deposited Zno Thin Film for Air and Vacuum Ambient Conditions
    (Elsevier, 2019) Özdoğan, Mehmet; Yiğen, Serap; Çelebi, Cem; Utlu, Gökhan
    Photoconduction mechanism of ZnO thin films that produced by Pulsed Electron Deposition method is systematically investigated by taking Transient Photocurrent Spectroscopy measurements for different atmospheres including high vacuum and air environments. Response and recovery rates of photocurrent in the air are faster than the rates in high vacuum condition. The results in the presented work clearly indicate that the photoconduction of ZnO thin films with high surface-area-to-volume ratio are surface-related and mostly governed by adsorption/desorption of oxygen and water molecules in the atmosphere. Therefore, the high surface interaction tendency of ZnO surface with the atmosphere inevitably leads to charge transfer from surface to adsorbates and/or vice versa.
  • Article
    Citation - WoS: 5
    Citation - Scopus: 6
    Manufacturing Radar-Absorbing Composite Materials by Using Magnetic Co-Doped Zinc Oxide Particles Synthesized by Sol-Gel
    (SAGE Publications Inc., 2020) Atay, Hüsnügül Yılmaz; İçin, Öykü
    An indicator of being a strong country in today's world is that they have powerful weapons. In this sector where science is used exceedingly, the "stealth" takes an important place. Radar-absorbing materials are used in stealth technology to disguise an object from radar detection, such that it can allow a plane to be perceived as a bird. In this study, Co-doped zinc oxide reinforced styrofoam sheet composites were manufactured as radar-absorbing materials. For this purpose, Co-doped zinc-ZnO particles were synthesized via the Sol-Gel method with doping concentrations of 0%, 3%, 6%, 9%, and 12%. They were embedded in a styrofoam matrix with different loading levels to see the concentration dependence. The as-prepared powders were characterized by using X-ray diffraction and Scanning Electron Microscope-Energy Dispersive Spectroscopy. Magnetic characterization of samples was carried out using a vibrating sample magnetometer. Finally, the radar-absorbing test was applied with a network analyzer to achieve the main purpose of this research. It was concluded that Co-doped zinc oxide reinforced composites have electromagnetic properties that indicate potential applications in the radar-absorbing area.
  • Article
    Citation - WoS: 31
    Citation - Scopus: 34
    Dual Remediation of Waste Waters From Methylene Blue and Chromium (vi) Using Thermally Induced Zno Nanofibers
    (Elsevier, 2020) Elhousseini, Mohamed Hilal; Isık, Tuğba; Kap, Özlem; Verpoort, Francis; Horzum, Nesrin
    Electrospun zinc oxide (ZnO) nanofibers have been significantly improved via a simple heat treatment modification. The present work reports an intriguing cost-effective microstructure tuning, by drastically dropping the temperature of the calcined sample during the cooling period, to get highly photocatalytically active ZnO nanofibers. The calcination temperatures are deducted from thermogravimetric analysis, the phase and purity are confirmed by X-ray diffraction, while the morphology and texture have been revealed by field emission scanning electron microscopy and high-resolution transmission electron spectroscopy. X-ray photoelectron spectroscopy was conducted to get further insight on the surface composition and oxidation states, while N-2-adsorption isotherms were analyzed using the Brunauer-Emmet-Teller methodology. The crystallinity, surface area, and porosity of the ZnO nanofibers, as well as the exposure of active sites, have been enhanced by the rapid cooling method. Photodegradation activity toward methylene blue was improved from 88% to 94%, and 85% to 97%, for free cooled and rapid cooled samples calcined at 300 degrees C and 500 degrees C respectively. The adsorption of chromium (VI) was also tested and reached around 85 mg/g at 100 ppm without being saturated, thereby highlighting one of the most cost-effective performance-enhancing modifications so far that could be extended on different metal oxide nanomaterials.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 22
    Zinc Oxide and Metal Halide Perovskite Nanostructures Having Tunable Morphologies Grown by Nanosecond Laser Ablation for Light-Emitting Devices
    (American Chemical Society, 2020) Demirci Sankir, Nurdan; Abdullayeva, Nazrin; Altaf, Çiğdem Tuç; Kumtepe, Alihan; Yılmaz, Nazmi; Coşkun, Özlem; Sankir, Mehmet; Kurt, Hamza; Çelebi, Cem; Yanılmaz, Alper
    This work reports a one-pot chemical bath deposition (CBD) method for the preparation of selectively grown, morphology-tunable zinc oxide (ZnO) nanostructures provided via straightforward nanosecond fiber laser ablation. Nanosecond fiber laser ablation is different from lithographic methods due to its simple, time saving, and efficient film scribing abilities. Here, multiple morphologies of the ZnO nanostructures on the same substrate have been grown via laser ablation of the ZnO seeding layer. Selective and controlled ablation of the titanium layer, ZnO growth inhibitor, resulted in systematic growth of nanorod arrays, while the application of extensive fluence energies resulted in the penetration of the laser beam until the glass substrate induced the nanoflake growth within the same CBD environment. The laser penetration depth has been numerically investigated via COMSOL Multiphysics heat module simulations, and the optical variations between two nanostructures (nanorod and nanoflake) have been examined via Lumerical FDTD. The simultaneous growth of two morphologies served as an efficient tool for the enhancement of photoluminescence intensities. It increased the average charge carrier lifetimes of the thin films from approximately 2.01 to 9.07 ns under the same excitation wavelengths. The amplification in PL performances has been accomplished via the capstone of all-inorganic halide perovskite (IHP) deposition that brought a successful conclusion to lifetime responses, which have been increased by 1.4-fold. The development of IHP sensitized nanoscaled multimorphological ZnO thin films can, therefore, be used as potential nanomaterials for light-emitting-device applications. © 2020 American Chemical Society.