WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

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Has files: YesInstitution Author: search.filters.institutionAuthor.Karabudak, Engin

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Now showing 1 - 3 of 3
  • Article
    Citation - WoS: 7
    Citation - Scopus: 8
    Investigation of Oxygen Evolution Reaction Performance of Silver Doped Ba0.5sr0.5co0.8fe0.2o3-Delta Perovskite Structure
    (Springer, 2020) Göl, Emre Yusuf; Aytekin, Ahmet; Karabudak, Engin; Karabudak, Engin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    Studies on novel electrochemical catalyst synthesis for efficient oxygen evolution reaction (OER) attract the attention of researchers. In general, changing of synthesis method and the doping metal affect the electrochemical activities of BSCF. In this work, silver doped Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF-Ag) perovskite structure is shown to be a better electrocatalyst for oxygen evolution reaction (OER) due to its lower overpotential and extended durability. BSCF structure was synthesized by the EDTA-citric acid method. Appropriate amount of Ba(NO3)(2) and EDTA were dissolved 0.1 M NH4OH solution. Nitrate salts of other metals were dissolved in distilled water, then mixed with prepared Ba(NO3)(2) solution. The mixture was stirred at 70 degrees C until gelation occurred. The gelled samples obtained were baked in a drying oven at 250 degrees C for 24 h before being calcined at 1000 degrees C for 12 h. To achieve a current density of 10 mA cm(-2), BSCF-Ag has required an overpotential of 0.36 V, which is very low compared to BSCF. To determine the stability of BSCF-Ag, continuous chronopotentiometry tests were carried out for 5 h and at a constant current density of 10 mA cm(-2). BSCF-Ag was characterized by XRD, SEM, and XPS.
  • Article
    Citation - WoS: 12
    Citation - Scopus: 13
    History of Spectroscopy and Modern Micromachined Disposable Si Atr-Ir Spectroscopy
    (Taylor and Francis Ltd., 2018) Koç, Mert; Karabudak, Engin; Karabudak, Engin; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    In this article, the historical development of spectroscopy is examined and the spectroscopy devices used today are described. Then, we focus on infrared (IR) spectroscopy, which cannot give valuable signal in aqueous solution. Attenuated total reflection (ATR)-IR technique solves the problem. In addition, we specifically mention newly developed disposable ATR-IR crystals and micromachined silicon (Si) ATR-IR. Disposable crystal systems and microfluidics systems can be integrated with existing miniature ATR analyzers. If the integration is successful, the technique might be used in biomedical measuring instruments, reactions' analyses, and ultra-high-pressure analyses.
  • Article
    Citation - WoS: 47
    Citation - Scopus: 49
    Simultaneous Identification of Spectral Properties and Sizes of Multiple Particles in Solution With Subnanometer Resolution
    (John Wiley and Sons Inc., 2016) Karabudak, Engin; Karabudak, Engin; Brookes, Emre; Lesnyak, Vladimir; Gaponik, Nikolai; Eychmüller, Alexander; Walter, Johannes; Segets, Doris; Peukert, Wolfgang; Wohlleben, Wendel; Demeler, Borries; Cölfen, Helmut; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
    We report an unsurpassed solution characterization technique based on analytical ultracentrifugation, which demonstrates exceptional potential for resolving particle sizes in solution with sub-nm resolution. We achieve this improvement in resolution by simultaneously measuring UV/Vis spectra while hydrodynamically separating individual components in the mixture. By equipping an analytical ultracentrifuge with a novel multi-wavelength detector, we are adding a new spectral discovery dimension to traditional hydrodynamic characterization, and amplify the information obtained by orders of magnitude. We demonstrate the power of this technique by characterizing unpurified CdTe nanoparticle samples, avoiding tedious and often impossible purification and fractionation of nanoparticles into apparently monodisperse fractions. With this approach, we have for the first time identified the pure spectral properties and band-gap positions of discrete species present in the CdTe mixture.