Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 3Citation - Scopus: 4A Facile Method for Boosting the Graphitic Carbon Nitride's Photocatalytic Activity Based on 0d/2d S-Scheme Heterojunction Nanocomposite Architecture(Elsevier, 2024) Kahraman, Zeynep; Kartal, Uğur; Gent, Aziz; Alp, EmreGraphitic carbon nitride (g-C 3 N 4 ) has received significant interest as a metal -free photocatalyst. The S -scheme photocatalytic system has great potential to improve the charge separation in semiconductor photocatalysts. In this study, we have fabricated non-toxic and low-cost photocatalytic nanocomposites of 0D/2D S -scheme heterojunction composed of iron oxide and graphitic carbon nitride by a facile method. The developed facile method provides a sustainable way with a high atom economy to further enhance the photocatalytic performance of exfoliated g-C 3 N 4 . The 0D -iron oxide/2D-C 3 N 4 exhibited nearly 10 times better than bulk g-C 3 N 4 and almost 60 % better than exfoliated g-C 3 N 4 under simulated solar light irradiation. The experimental results demonstrated that the effective charge -carrier mechanism led to an improved generation of reactive oxygen species (ROSs), resulting in an impressive photocatalytic performance. A serial photocatalytic test was also conducted to understand photocatalytic reaction mechanisms with various scavengers.Article Citation - WoS: 9Citation - Scopus: 9Zno Nanostructures for Photocatalytic Degradation of Methylene Blue: Effect of Different Anodization Parameters(Springer, 2022) Öksüz, Ahmet Emrecan; Yurddaşkal, Metin; Kartal, Uğur; Dikici, Tuncay; Erol, MustafaIn 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: 30Energy Harvesting Nanogenerators: Electrospun Β-Pvdf Nanofibers Accompanying Zno Nps and Zno@ag Nps(Elsevier, 2021) Zeyrek Ongun, Merve; Oğuzlar, Sibel; Kartal, Uğur; Yurddaşkal, Metin; Cihanbeğendi, Özge; Zeyrek Ongun, Merve; Oğuzlar, Sibel; Kartal, Uğur; Yurddaşkal, Metin; Cihanbeğendi, ÖzgeThis paper aims to demonstrate that synthesized nano-scale zinc oxide (ZnO) and different concentrations (1, 3 and 5 wt%) of silver-doped zinc oxide (ZnO@Ag) nanoparticles (NPs), which were employed to enhance the piezoelectric content of the electrospun β-phase poly (vinylidene fluoride) PVDF nanofibers, may be an alternative for usual semiconductor dopant. The structural and morphological properties of all the synthesized materials were investigated. The impedance and the capacitance values of the manufactured nanogenerators were also investigated at room temperature. The peak-to-peak amplitude output voltage data of ZnO NPs and ZnO@Ag NPs doped PVDF-based electrospun nanomats were measured using digital oscilloscope while a finger-tapping action at a frequency of ∼1 Hz was conducted. The electrical output of 5 wt% Ag-doped ZnO-based β-PVDF nanofibers increased from 0.5 to 1.5 V compared to undoped β-PVDF samples. These findings have a wide range of auspicious applications, including energy harvesting devices, portable electronic systems, and self-powered electrical gadgets that can be worn.Article Citation - WoS: 8Citation - Scopus: 7A Comparative Study on Structural, Morphological and Photocatalytic Properties of Anodically Grown Zno Nanowires Under Varying Parameters(Springer, 2021) Özdemir, Erdem Tevfik; Kartal, Uğur; Dikici, Tuncay; Erol, Mustafa; Yurddaskal, MetinIn this study, zinc oxide (ZnO) nanowires (NWs) were successfully produced on Zn plates through electrochemical anodization in potassium bicarbonate aqueous electrolytes with different production parameters in two groups as applied voltage and anodization time. Subsequently, the ZnO NWs were annealed at 300 degrees C for 1 h in air atmosphere to increase crystallinity and remove organic residues. Structural and morphological properties were determined through X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The effect of anodization parameters on the structure of ZnO NWs and thus their photocatalytic activities were evaluated in detail by UV spectrophotometer. The results pointed out that, the most effective nanostructure on the photocatalytic degradation of methylene blue was obtained in the sample that was anodized for 30 min under 30 V at room temperature with a degradation efficiency of 90.6% after 11 h. This result shows that the NW-structured ZnO materials are promising to be used as effective photocatalysts in the removal of organic pollutants by solar energy and their conversion to green compounds.