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: 103Citation - Scopus: 113Preparation 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, BahmanThe 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: 6Citation - Scopus: 6Photocatalytic Activity of Dye-Sensitized and Non-Sensitized Go-Tio2 Nanocomposites Under Simulated and Direct Sunlight(Wiley-Blackwell, 2022) İlhan, Hatice; Durmaz Çaycı, Gamze Belkis; Aksoy, Erkan; Diker, Halide; Varlıklı, CananGraphene oxide (GO), amine-modified graphene oxide (mGO), and N-TiO2 composites were synthesized by low-temperature hydrothermal method and characterized by using X-ray diffraction, X-ray photoelectron spectroscopy, FTIR, and BET analysis techniques. The films of synthesized TiO2, mGO:TiO2, N-TiO2, GO:TiO2, GO:N-TiO2, and commercially available P25 were prepared by doctor blade method. These films and their perylene-3,4,9,10-tetracarboxy tetrabutylester (PTE)-sensitized forms were employed as photocatalysts for the photodegradation of rhodamine-B (RhB) under Xe lamp and direct sunlight irradiations. Independent from the irradiation source, the photocatalytic order of the non-sensitized films were GO:N-TiO2 > GO:TiO2 > N-TiO2 > mGO:TiO2 > TiO2 > P25, but seven and 15 folds of increments were detected under direct sunlight irradiation. PTE-sensitized catalyst films exhibited more than two folds of increase in the photocatalytic rate constants compared to their non-sensitized counterparts under Xe lamp irradiation. Under direct sunlight irradiation no matter which photocatalyst was used, the photocatalytic activity of these films was enhanced seven folds. Reusability tests revealed no significant changes in the photocatalytic rate constants obtained with both the non-sensitized and sensitized films.Article Citation - WoS: 1Citation - Scopus: 1Substrate Effects on Electrical Parameters of Dirac Fermions in Graphene(Elsevier, 2021) Tıraş, Engin; Ardalı, Şükrü; Fırat, Hakan Asaf; Arslan, Engin; Özbay, EkmelThe substrate effects on the electronic transport properties of single-layer graphene on TiO2/Si substrate have been studied. The Hall mobility, sheet carrier density, and transport lifetime were obtained from the temperature-dependent Hall measurements, while the in-plane effective mass, quantum lifetime was obtained from the temperature-dependent variation of the Shubnikov de Haas (SdH) oscillations that were made at 1.8 to 45 K temperature range and up to the magnetic field of 11 T. The measurement results showed that in SLG/TiO2/ Si sample, there were 2.36 +/- 0.12x1016 m-3 amounts of 3D carriers coming from the substrate. In our previous studies, 3D carrier densities were measured as 6.07x1016 m-3 and zero for SLG/SiO2/Si and SLG/SiC sample, respectively. This result shows that the 3D carriers formed in the structure are significantly changed by a substrate. The scattering mechanisms were determined using the zt/zq ratio. The ratio values obtained as 3.66. This value obtained was compared with the values we found for SLG/SiC (zt/zq=1.36) sample and SLG/TiO2/Si (zt/zq=3.08) sample our previous study. The results show that small-angle scattering is dominant in SLG/SiC sample, but large-angle scattering is dominant in SLG/SiO2/Si and SLG/TiO2/Si samples. The charged impurity scattering is the dominant scattering mechanism in SLG/TiO2/Si and SLG/SiO2/Si samples, whereas in SLG/SiC samples, a short-range scattering mechanism such as lattice defects can be said to affect the electronic transport.Article Citation - WoS: 6Citation - Scopus: 6Esterification of 1-Octanol on Clinoptilolite-Supported Tio2 Catalysts(Springer Verlag, 2019) Özyağcı, Bensu; Şahin, Volkan; Karabakan, AbdulkerimIn this study, a natural type of zeolite, Clinoptilolite (CLI), is used as a support for TiO2. First, TiO2-supported heterogeneous catalysts originated from the high temperature calcination of TiCl4 groups, which were thermally immobilized on clinoptilolite, were obtained. Powder-XRD and EDX analyzes showed that the oxide form of Ti-immobilized on dealuminated clinoptilolite were formed in the anatase phase, and the zeolite structure was preserved. As seen in TGA/DTA analyzes, this catalyst could be efficient and have high stability for many reactions. Second, the esterification reaction of 1-octanol with acetic acid is used as a reference reaction for this catalyst.