Yazar "Gullu, Emre" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • [ X ]
    Öğe
    Experimental and theoretical study: Design and implementation of a floating photovoltaic system for hydrogen production
    (Wiley, 2022) Gullu, Emre; Mert, Basak Dogru; Nazligul, Huseyin; Demirdelen, Tugce; Gurdal, Yeliz
    In this study, lab-made modified graphite cathodes were used to design and implement floating PV assisted alkaline electrolysis cell. The influence of temperature on PV performance was studied both experimentally and theoretically, and the PV module performance was investigated in floating as well as non-floating modes. Power generation of floating PV panel and non-floating PV panel at four different air temperatures was examined. Although there was no substantial improvement in power generation at 6 degrees C or 16 degrees C, values improved by 6.25% and 10.75% at 24 degrees C and 37 degrees C, respectively. For alkaline electrolysis cell part of this system, the graphite (G) cathode was galvanostatically coated with nickel (G/Ni) and decorated with cobalt nano-particles (G/Ni/Co). The characterization of the electrode was achieved using X-Ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). The Co(111)-decorated Ni was determined by XRD, the electrode surface was very rough in FE-SEM micrographs, the detected features provided a larger contact area that supported the formation of simultaneous electrochemical reactions. The electrochemical behavior of electrodes were determined in 1 M KOH by cyclic voltammetry (CV). The modified cathode (G/Ni/Co) enhanced the hydrogen production performance owing to lower hydrogen onset potential. Electronic structure calculations were carried out in order to investigate water as well as proton adsorption on a Co-decorated Ni(111) surface. Density Functional Theory (DFT) calculations identified the role of Co cluster and Ni surface on water and proton adsorptions. According to our knowledge of the literature to date, the practical and theoretical analysis of a floating PV assisted-an alkaline electrolysis system that worked with the laboratory-made electrodes has not been performed before. Results showed that floating PV panels were beneficial than land mounted panels and the G/Ni/Co enhanced the hydrogen generation performance of the system.
  • [ X ]
    Öğe
    Investigation of Inhibition Performance of Phenytoin for Mild Steel Protection in HCl Solution: Electrochemical and Quantum Theoretical Approaches
    (2022) Nazlıgül, Hüseyin; Gullu, Emre; Mert, Mehmet Erman; Mert, Başak Doğru
    In this study, the application potential of the expired \"Epdantoin\" drug which includes phenytoin (EP) as the corrosion inhibitor was investigated. For this purpose, the electrochemical impedance spectroscopy measurements and polarization curves were obtained for 168 hours immersion period in 0.5 M HCl in the absence and presence of various concentration of EP. The experimental results were compared with quantum theoretical parameters in order to present adsorption behavior of EP. The adsorption equilibrium constant and Gibbs free energy were calculated as 5000 M-1 and -31,05 kj mol-1, respectively. The calculated HOMO and LUMO values were -6.67 eV and -0.72 eV, respectively. Results indicated that EP is a convenient candidate of corrosion inhibitor for mild steel in HCl medium.