WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

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

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Department: search.filters.department.İzmir Institute of TechnologySubject: search.filters.subject.Nanomaterials

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  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Speciation of Inorganic and Organometallic Arsenic in Various Matrices With a Novel Spme Fiber Functionalized With Iron Nanoparticles Prior To Lc-Icp Determination
    (Elsevier, 2025) Boyaci, Ezel; Cagir, Ali; Shahwan, Talal; Eroglu, Ahmet E.
    A novel SPME-LC-ICP-MS methodology is described for the simultaneous microextraction/speciation/determination of the metabolically critical inorganic and organoarsenic species, namely, As(III), As(V), dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA) in natural waters such as drinking and geothermal waters, and biological fluids such as urine. The novelty of the study stems also from the use of home-made SPME fibers for the extraction process, and from the proposed methodology needing no derivatization step. SPME fibers were prepared with in-tube capillary template approach through the immobilization of iron nanoparticles into agarose matrix. The fibers demonstrated reproducible extraction (<10 % RSD), good mechanical strength and good solvent resistivity. The separation of the analytes was realized by HPLC with a strong anion exchange column via gradient elution using different concentrations of (NH4)(2)CO3 (pH 8.50), and the on-line detection of eluted analytes was achieved by ICP-MS. The validity of the proposed methodology was verified via the analysis of certified reference materials (SRM 1643e, Natural Water-Trace Elements, and SRM 2669, Arsenic Species in Frozen Human Urine) and through spike recovery tests. The values of percentage recovery for SRM 2669 were 90.7 % for As(III), 99.8 % for As(V), 93.6 % for DMA, and 85.9 % for MMA. A good correlation was also found between the certified (60.45 mu gL(-1)) and determined (59.00 mu gL(-1)) values for SRM 1643e. Moreover, the speciation capability of the method was demonstrated on various natural waters and biological fluids.
  • Article
    Citation - WoS: 10
    Citation - Scopus: 10
    The Role of Effective Catalysts for Hydrogen Production: a Performance Evaluation
    (Pergamon-elsevier Science Ltd, 2025) Goren, A. Yagmur; Temiz, Mert; Erdemir, Dogan; Dincer, Ibrahim
    In recent years, research on hydrogen (H2) production for alternative and environmentally-benign energy solution as fuel, storage medium and feedstock has been one of the most highly demanded subjects. It aims to reduce the pressures set by carbon dioxide emissions and the depletion of fossil fuel supplies. Nevertheless, largescale H2 production is limited by its high cost and low yield. The distinct photo-electrochemical characteristics of catalysts have shown them to have great promise for enhancing the production of H2. This article presents an updated and comprehensive review of enhanced H2 production using various catalysts in biological, thermochemical, and water-based processes. Various operational parameters (reactor configuration, catalyst dosage, catalyst type, catalyst modification methods, temperature, pH, and inoculum type) are summarized to improve the H2 production performance and reduce the environmental impacts and costs of these processes. For instance, in dark fermentation, biological H2 production is enhanced by 3.2-38 % with certain metal catalysts. Overall, results revealed that catalysts, specifically inorganic catalysts such as iron, nickel, titanium oxide, and silver, have improved the production rate of H2. This review has provided the application fields and working principles of catalysts in different H2 production processes. Finally, we suggested the main concerns that need to be prioritized in the long-term advancement of H2 production using catalysts.