Browsing by Author "Begar, Ferit"

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Design and Synthesis of Anthracenetetrone-Based Redox-Active Porousorganic Polymer as a Cathode Material for Zinc-Ion Batteries
(01. Izmir Institute of Technology, 2023-07) Begar, Ferit; Büyükçakır, Onur; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Aqueous zinc ion batteries (AZIBs) are a new class of energy storage devices with significant potential for large-scale applications. However, developing suitable cathode materials that can efficiently and reversibly accommodate Zn2+ ions remains a key obstacle in advancing this technology. Porous organic polymers (POPs) are materials characterized by their interconnected network of pores at the molecular level. These versatile polymers exhibit unique properties such as high surface area, tunable porosity, and diverse functionality. POPs hold great potential for various technological advancements, and recently, they have attracted significant interest in energy storage applications due to their exceptional physical and chemical properties, which endow structural durability and electrochemical superiority. In this study, we reported the synthesis of a new redox-active quinone-rich porous organic polymer (rPOP) as a cathode material for AZIBs. The highly porous nature of rPOP enables successful Zn2+ diffusion into the redox centers. The structural durability of the polymeric materials provides ultra-long cycle life. The cell containing rPOP cathode delivered a discharge capacity of 120 mA h g-1 at a current density of 0.1 mA g1 . Most importantly, the rPOP revealed extraordinary cycling stability at 1.0 A g-1 for 10000 charge/discharge cycles and at 2.0 A g-1 for 30000 charge/discharge cycles with capacity retentions of %95 and %66, respectively. The detailed investigation of the charge storage behavior of rPOP cathode, using ex/in-situ analysis, revealed that H+ acts as a secondary charge carrier along with the Zn2+, contributing to 17% of the overall capacity. This study demonstrates the effective utilization of POPs as a cathode material for AZIBs, and we believe that it will attract the attention of researchers in the energy storage field.
Nitrate Sensing With Molecular Cage Ionophores: a Potentiometric Approach
(Royal Soc Chemistry, 2025) Onder, Ahmet; Begar, Ferit; Kibris, Erman; Buyukcakir, Onur; Yildiz, Umit Hakan; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
Nitrate ions are widespread environmental pollutants in water and soil, posing critical risks to both human health and ecosystems. This study introduces a molecular cage as a novel ionophore for potentiometric nitrate-selective ion-selective electrodes (ISEs) designed for enhanced specificity and sensitivity. Among six synthetic candidates, the electrode incorporating a 1,3,5-tri(p-hydroxyphenyl)benzene-based chlorotriazine pillared cage molecule (CAGE-1) exhibited superior performance, characterized by a linear response in the nitrate concentration range of 1.0 x 10-5 to 1.0 x 10-1 M, with a high coefficient of determination (R2 = 0.9971) and a slope of -53.1 +/- 1.4 mV dec-1. The electrode also achieved a limit of detection of 7.5 x 10-6 M. These findings highlight the potential of molecular cages as ionophores for nitrate sensing in environmental applications.
Redoks-aktif Gözenekli Organik Polimerlerin Sentezi ve Çinko İyon Pillerde Katot Malzemesi Olarak Kullanımları
(2023) Büyükçakır, Onur; Şimşek, Gizem; Erözen, Yaren Naz; Geçalp, Yasmin; Begar, Ferit; Çanakçı, Utku Cem; 01. Izmir Institute of Technology; 04. Faculty of Science; 04.01. Department of Chemistry
Proje kapsamında redoks-aktif yapı taşlarının kullanımı ile yeni redoks aktif gözenekli organik polimerler (rGOP'ler) sentezlenmiştir. Sentezlenen polimerler şarj edilebilir sulu çinko(Zn)-iyon pillerde (ÇİP) katot malzemesi olarak test edilmişlerdir. Sentezlenen polimerlerden rGOP-1 yüksek kapasite göstermesinin yanında sabit voltaj çıkışına imkan sağlayacak düz deşarj platosuna ve 2.0 A g-1 akım yoğunluğunda 30000 şarj/deşarj döngüsü sonunda başlangıç kapasitesinin %66?sını koruyarak uzun döngü ömrüne sahip olduğunu göstermiştir. rGOP-1?in ağsı yapısı, redoks-aktif küçük organik bileşiklerde sıklıkla karşılaşılan deşarj ürünlerinin elektrolit içerisinde çözünürlük sorununu gidermiş, uzun ve kararlı bir şarj/deşarj çevrim ömrüne sahip olmasını sağlamıştır. Gözenekli ve ?-konjuge iskelet yapısı hızlı iyon ve yük transfer süreçlerini kolaylaştırarak olağanüstü elektrokimyasal performans sergilemesinde önemli rol oynamıştır. Ayrıca, operando ve ex-situ analizler sayesinde rGOP-1?in çalışma mekanizması incelenmiştir. Sulu ÇİP?lerde görülen proton (H+) yardımcı iyon etkileşimi detaylı bir biçimde analiz edilmiş ve katotların yük depolama mekanizması ayrıntılı bir şekilde çalışılmış ve her bir iyonun (Zn2+ ve H+) toplam kapasiteye katkıları kantitatif bir biçimde belirlenmiştir. Proje kapsamında sentezlenen her bir rGOP içerdikleri farklı redoks-aktif grupları ve kullanılan kimyanın farklılığı sayesinde projenin yeniliğine katkı sağlamakla kalmayıp, yapı-özellik ilişkilerinin kurulmasında önemli rol oynamıştır. Her bir rGOP için gerçekleştirilen rutin galvanostatik ve potentiostatik ölçümler sayesinde polimerik yapıların katot malzemesi olarak ÇİP?lerde elektrokimyasal performansları değerlendirilmiştir. Buradan elde edilen bilgiler ve geri dönüşler kullanarak ÇİP?ler için yeni rGOP?ler üretilmiştir. Öncül analizleri tamamlanan rGOP-7 ve rGOP-8 1.0 A g-1 akım yoğunluğunda yüksek kapasite ile birlikte 10000 gibi uzun şarj/deşarj döngüsüne sahip oldukları gösterilmiştir. Sentezlenen polimerlerin sahip olduğu yapısal farklılıkların ÇİP?lerde katot olarak elektrokimyasal performans üzerindeki etkisinin araştırılması yönünden oldukça önemlidir. Bahsedilen farklılıklar ve ilerlemeler göz önüne alındığında, projeden elde edilen bulgular yapı-özellik arasındaki ilişkinin kurulmasında önemli bir rol üstlenmiştir. Projeden elde edilen tüm bilgi ve deneyimler, yeni nesil enerji depolama sistemleri için rasyonel kimyasal tasarımların geliştirilmesinde büyük katkılar sunacağı düşünülmektedir.
Citation - WoS: 12
Citation - Scopus: 11
Synthesis of Triazole-Linked Porous Cage Polymers: Modulating Cage Size for Tailored Iodine Adsorption
(Amer Chemical Soc, 2024) Begar, Ferit; Erdogmus, Mustafa; Gecalp, Yasmin; Canakci, Utku Cem; Buyukcakir, Onur; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
We present the synthesis of two triazole-linked porous cage polymers (pCAGEs) using two D-3h symmetric shape-persistent organic cages of different sizes as monomers. We observed that expanding the size of the cage monomer resulted in an improved surface area, pore volume, and iodine vapor uptake capacity of up to 4.02 g g(-1) at 75 degrees C under ambient pressure. Also, embedding molecular organic cages into pCAGEs boosted their iodine adsorption performances compared to their discrete molecular counterparts, model compounds (mCAGEs), due to their open pore channels, enabling the efficient diffusion of iodine into the binding sites. The pCAGEs showed promising iodine adsorption efficiencies from a concentrated KI/I-2 aqueous solution with a high iodine uptake capacity of up to 3.35 g g(-1). The iodine uptake capacities of pCAGEs differ in vapor and aqueous solutions, which suggests that tuning the cage size allows us not only to control the textural properties of pCAGEs but also to tailor their iodine adsorption performances in vapor and water. Iodine adsorption mechanisms of pCAGEs were investigated using ex situ structural characterization techniques, revealing strong interactions of adsorbed iodine species with nitrogen-rich groups and phenyl rings of the pCAGEs. Notably, pCAGEs demonstrated remarkable regeneration and reusability, maintaining 86% of their initial adsorption capacities over five adsorption/desorption cycles, highlighting their potential for practical applications. These findings contribute to a fundamental understanding of the structure-property relationship for cage-based polymeric materials and provide insights into the development of high-performance adsorbents for iodine capture.
Citation - WoS: 38
Citation - Scopus: 39
Ultralong-Life Quinone-Based Porous Organic Polymer Cathode for High-Performance Aqueous Zinc-Ion Batteries
(American Chemical Society, 2023) Büyükçakır, Onur; Yüksel, Recep; Begar, Ferit; Erdoğmuş, Mustafa; Arsakay, Madi; Lee, Sun Hwa; Kim, Sang Ouk; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of Technology
We synthesized and studied a redox-active quinone-basedporousorganic polymer (rPOP) and found ultralong cycle life: it is a promisingorganic cathode for aqueous zinc-ion batteries (ZIBs). It has highphysicochemical stability and enhanced intrinsic conductivity fromits fused-aromatic conjugated skeleton. rPOP's high porosityallows for efficient Zn2+ infiltration through the poresduring charging-discharging cycles and contributes to the efficientutilization of redox-active quinone units. It delivers a specificcapacity of 120 mAh g(-1) at a current density of0.1 A g(-1) with a flat and long discharge plateau,which is critically important to provide a stable voltage output.It provides ultralong cycle life at a current density of 1.0 A g(-1) for 1000 and at 2.0 A g(-1) for 30 000cycles, with initial capacity retention of 95 and 66%, respectively.The co-insertion (Zn2+ and H+) charge storagemechanism was investigated using various electrochemical measurementsand ex/in situ structural characterization techniques, and is explainedherein. These findings contribute to a better understanding of thestructure-property relationship for rPOP and open a new avenuefor new organic cathode materials for high-performance next-generationaqueous batteries.