Yazar "Üstün, Tugay" seçeneğine göre listele

Listeleniyor 1 - 4 / 4
  • [ X ]
    Öğe
    CdSO4-CdS Composite nanowires synthesized by arc discharge method
    (2022) Üstün, Tugay; Eskizeybek, Volkan; Toumiat, Amor; Avcı, Ahmet
    Herein, we successfully carried out the of CdS nanowires doped with CdSO4 nanoparticles by arc discharge method. For this, two cadmium rods with high purity as anode and cathode electrodes were submerged in a liquid nitrogen medium. The cathode electrode was filled with micro-sized sulfur powder to synthesize CdS nanowires. CdS nanowires were obtained by oxidation using low temperature with CdSO4 nanoparticles. After the arc discharge process, the resultant product was characterized to reveal structural and morphological properties. XRD and electron EDX analyses exposed the coexistence of the CdS and CdSO4 phases. Scanning electron microscopy (SEM) investigations revealed that the synthesized nanostructures formed in a 1D wire nanostructure morphology with a diameter of less than 10 nm and several micrometers in length. Besides, the transmission electron microscopy (TEM) analysis was utilized to monitor the CdSO4 nanoparticles located on CdS nanowires surface. It has been found that the absorption band blue-shifted with 0.53 eV. This blue shift originated from the quantum confinement in the nanoparticles.
  • [ X ]
    Öğe
    FACILE AND TEMPLATE-FREE SYNTHESIS OF CuO NANOPARTICLES
    (2019) Üstün, Tugay; Eskizeybek, Volkan; Avcı, Ahmet Kerim
    Copper oxide (CuO) nanoparticles were synthesized successfully by arc discharge methodin an aqueous medium. Arc discharge was ignited between two copper electrodes and an exhaustivecharacterization of morphology and crystalline structure of the drawn up copper oxide nanoparticleswere studied. Electron microscopy analyses revealed that the grown CuO nanoparticles are irregularlyshaped with nominal diameters in the interval of 10-50 nm. XRD results show the as-synthesizedparticles contain only CuO peaks without any impurities. The results procure a simple, cheap andresponsive method for preparing single-phase CuO nanoparticles.
  • Küçük Resim
    Öğe
    GaN/ZnO hybrid nanostructures for improved photocatalytic performance: One-step synthesis
    (TUBITAK, 2023) Üstün, Tugay; Haspulat Taymaz, Bircan; Eskizeybek, Volkan; Kamış, Handan; Avcı, Ahmet
    Nanostructured semiconductor materials are considered potential candidates for the degradation of textile wastewater via the photocatalytic process. This study aims to produce hexagonal gallium nitride (GaN) nanoplates and zinc oxide (ZnO) nanoparticles in a deionized water environment utilizing a one-step arc discharge process. Detailed characterization of samples has been completed via scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and UV visible spectroscopy methods. The hybrid nanostructure morphologies consist of nanoplates and nanorods of different sizes. The photoperformance of GaN/ZnO hybrid nanostructures was assessed via the malachite green (MG) dye degradation under UV exposure. Under UV exposure, the degradation yield reached 98% in 60 min. Compared to individual ZnO and GaN nanoparticles, the photocatalytic reaction rate of the GaN/ZnO photocatalyst is 2.2 and 3.6 times faster, respectively. Besides, the GaN/ZnO hybrid nanostructures show excellent photocatalytic stability. The energy consumption of the photocatalytic degradation in the presence of GaN/ZnO hybrid nanostructures was 1.688 kWhL–1. These results demonstrate that the GaN/ZnO hybrid nanostructures with improved photocatalytic activity are a reasonable option for the decomposition of textile wastewater under UV light exposure.
  • [ X ]
    Öğe
    Selectively Nanocube Formation of Tungsten Oxide (WO3)
    (2020) Üstün, Tugay; Eskizeybek, Volkan; Avcı, Ahmet Kerim
    Metal oxide nanoparticles with tunable size and shape are of significant interest since these features allowtailoring their performance, functionality, and efficiency. Doping of metal oxide nanoparticles with metalcations proved to be an effective strategy for tailoring their electrical, optical, and microstructuralproperties. In this study, tungsten oxide (WO3) nanoparticles doped with selenium (Se) and lanthanum(La) catalysts were produced with a preferential nanocube morphology by arc discharge method. Se andLa catalysts were introduced into the tungsten (W) electrode acting as an anode, and the arc-discharge wasgenerated between two W electrodes in a deionized water medium. Structural and morphological featuresof the as-synthesized nanostructures were investigated by performing scanning electron microscopy(SEM) and transmission electron microscopy (TEM) analyses. Morphological analyses revealed that theresultant nanoparticles exhibited nanocube morphology with size ranges of 10 to 50 nm. X-ray diffraction(XRD) results proved the existence of highly crystalline monoclinic WO3 as an abundant structure. Weconfidently believe that the arc-discharge method can be utilized to produce various types ofnanostructures with tunable size and shape by tailoring process parameters, including the type of dopant.