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: 2Citation - Scopus: 2Investigation on the Keggin Anchored on Hydroxide-Functionalized Single-Walled Carbon Nanotubes as Superior Cathode for Aqueous Zinc-Ion Batteries(American Chemical Society, 2025) Chilufya, Langson; Sertbaş, Vahide; Aytekin, Ahmet; Karabudak, Engin; Emirdag-Eanes, MehtapRechargeable aqueous zinc-ion batteries (AZIBs) have become a viable option in electrochemical energy storage systems (EESS) owing to their inherent safety features and economic friendliness. Nonetheless, creating suitable cathode materials for AZIBs with high structural stability, good rate performance, and great capacity remains a significant challenge. Polyoxometalate (POM)-based nanohybrid materials have shown promising results in high cycling stability and great specific capacity. However, POMs susceptible to electrolyte dissolution and the sluggish Zn-ion (Zn2+) kinetics have significantly hampered their electrochemical performance as cathodes for AZIBs. Herein, we present a Keggin POM, K<inf>3</inf>[PW<inf>12</inf>O<inf>40</inf>]·nH<inf>2</inf>O (KPW<inf>12</inf>), anchored on hydroxyl (OH)-functionalized single-walled carbon nanotubes (SWOH) that were fabricated via a facile ultrasonication procedure. Employed as cathodes for AZIBs, the optimal KPW<inf>12</inf>/SWOH feature exhibited remarkable electrochemical performance. The system satisfied the Zn2+storage, achieving a reversible discharge capacity of 183 mAh g–1at a high current density of 5C with a flat and long discharge plateau after 160 cycles. The perfect synergistic contribution of the pseudocapacitive nature of the super-reduced state of KPW<inf>12</inf>and the electron-conductive network of SWOH was attributed to this exceptional electrochemical performance. Furthermore, the presence of oxygen in SWOH enhanced the transfer kinetics of electrons and smooth Zn2+diffusion while lowering the Zn2+migration energy barrier by providing more accessible active sites. This demonstrates remarkable promise in fabricating robust electrode materials optimized for integration within aqueous battery systems that pave the way for further research into POM-based materials for EESS. © 2025 Elsevier B.V., All rights reserved.Article Citation - WoS: 12Citation - Scopus: 13History of Spectroscopy and Modern Micromachined Disposable Si Atr-Ir Spectroscopy(Taylor and Francis Ltd., 2018) Koç, Mert; Karabudak, EnginIn 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: 47Citation - Scopus: 49Simultaneous Identification of Spectral Properties and Sizes of Multiple Particles in Solution With Subnanometer Resolution(John Wiley and Sons Inc., 2016) Karabudak, Engin; Brookes, Emre; Lesnyak, Vladimir; Gaponik, Nikolai; Eychmüller, Alexander; Walter, Johannes; Segets, Doris; Peukert, Wolfgang; Wohlleben, Wendel; Demeler, Borries; Cölfen, HelmutWe 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.