Browsing by Author "Ozok-Arici, Omruye"

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Benzotiyofen@pd as an Efficient and Stable Catalyst for the Electrocatalytic Oxidation of Hydrazine
(Elsevier Sci Ltd, 2022) Kaya, Sefika; Ozok-Arici, Omruye; Kivrak, Arif; Caglar, Aykut; Kivrak, Hilal
An efficient methods for the synthesis of 2-(2,5-dimethylphenyl)-3-iodobenzo[b]thiophene (4) is described, and investigated its anode catalyst performance by using electrochemical methods (CV, CA and EIS). When 2-(2,5dimethylphenyl)-3-iodobenzo[b]thiophene (4) is applied, the specific activity is found as 25.811 mA/cm(2). Interestingly, when Palladium (Pd) is electrochemically deposited on the benzothiophene derivative, the catalytic activity increased the 80.930 mA/cm(2). This result is highest than the current metal based anode catalyst. Moreover, EIS and CA measurements display that Pd doped benzothiophene organic catalyst have high stability, and give the low charge transfer resistance. Energy dispersive X-ray (SEM-EDX), electron microscopy, TEM are used for the determination of its surface morphology. As a result, 2-(2,5-dimethylphenyl)-3-iodobenzo[b]thiophene (4) may be alternative electro-catalysts in fuel cell applications.
Catalytic Electro-Oxidation of Hydrazine by Thymol Based-Modified Glassy Carbon Electrode
(Elsevier Sci Ltd, 2022) Sharif, Kawa Hama; Kivrak, Hilal; Ozok-Arici, Omruye; Caglar, Aykut; Kivrak, Arif
In the present, thymol based new organic compounds (4A , 4B and 4C) are designed and synthesized via Steglich Esterification Reactions and Pd-catalyst Sonogashira Coupling Reactions. After isolation and characterization, thymol based hybrid molecules are used for hydrazine (N2H4) electrooxidation reactions as anode catalysts. A variety of metal based anode catalyst have been reported in literature, but this study may be the first study for thymole based hybrid molecules as an anode catalyst in fuel cells. The performance of hybrid molecules was investigated via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in hydrazine solution. Hybrid 2-isopropyl-5-methylphenyl-4-oxo-4-(5-(p-tolylethynyl)thiophen-2-yl)butanoate (4C) gives the highest performance as 3.66 mAcm(-2) (17.24 mAmg(-1)). Our results displayed that natural products like thymol derivatives may be new generation anode catalyst for fuel cells, and they may be alternative for expensive Pd and Pt based metal anode catalyst.
Glucose Electrooxidation Study on 3-iodo-2-(aryl/Alkyl)benzo[b]thiophene Organic Catalyst
(Springer, 2022) Ozok-Arici, Omruye; Kaya, Sefika; Caglar, Aykut; Kivrak, Hilal; Kivrak, Arif
The compound 3-iodo-2-(aryl/alkyl)benzo[b]thiophene (4A-F) has been synthesized as an anode catalyst using the Sonogashira coupling reaction and the electrophilic cyclization reaction in moderate to excellent yields. The glucose electro-oxidation performance of these catalysts has been investigated by electrochemical methods, such as cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) in 1 M KOH + 1 M C6H12O6 solution. When Pd metal is electrochemically deposited on the organic catalyst to increase the electrocatalytic activities, the Pd@4A catalyst exhibits the highest catalytic activity with 0.527 mA/cm(2) current density than the 4A. The CA and EIS results prove that the Pd@4A catalyst has long-term stability and low charge transfer resistance and may be used in metal-organic catalyst systems as an anode catalyst to improve their performance. The results confirm that benzothiophene-based metal systems will be environmentally friendly materials in glucose fuel cells.
Synthesis of Novel Artemisinin Derivatives and Their Electrochemical Properties
(Wiley-v C H verlag Gmbh, 2022) Esen, Meryem; Kavak, Emrah; Ozok-Arici, Omruye; Ulas, Berdan; Kivrak, Hilal; Kivrak, Arif
In present, new artemisinin-based organic compounds (1-6) are designed and synthesized in excellent yields (up to 97 %) via Steglich Esterification reactions. All new artemisinin derivatives are tested as anode catalysts for hydrazine electrooxidation reactions with electrochemical methods in 1 M KOH/0.5 M N2H4 solution. Hybrid molecule 1 exhibits the best catalytic activity in hydrazine electrooxidation reaction with 2.28 mA cm(-2) value. Moreover, response surface methodology (RSM) is applied to investigate of optimum electrode conditions. By using optimum conditions, hydrazine electrooxidation is obtained as 3.55324 mA cm(-2). As a result, artemisinin-based hybrid compounds may be alternative, and next-generation anode catalyst for direct hydrazine fuel cells.
Synthesis of Thiophene/Furan-artemisinin Hybrid Molecules
(Wiley-v C H verlag Gmbh, 2022) Ozok-Arici, Omruye; Kavak, Emrah; Kivrak, Arif
Natural products with semi-synthetic molecules displays higher biological activities, and creates new biological properties for the treatment of diseases. Although, natural products like artemisinin have been used as a traditional medicine over thousands of years, structure and biological properties of many natural products were investigated in the 20th century. Design and synthesis of new biologically active compounds including natural products have very critical roles to find novel drug candidates. Herein, novel thiophene/furan bridge artemisinin derivatives were synthesized by starting from artemisinin. Firstly, benzothiophene derivatives are synthesized, then Steglich esterification reactions give the new artemisinin hybrid molecules with moderate to high yields.
Synthesis of Thymol Derivatives and Its Fuel Cell Performance as an Anode Catalyst
(Health & Environment Assoc, 2022) Sharif, Kawa Hama; Ozok-Arici, Omruye; Caglar, Aykut; Kivrak, Hilal; Kivrak, Arif
Direct glucose fuel cells, essentially produce electricity from glucose, offer several advantage and might be employed in a range of applications. Becuase of stability and non-volatile, Glucose have high-intensity density. When it is oxidized water and CO2 are formed. In the current investigation, designed and synthesized new organic anode catalyst by using Thymol derivatives. Thymol based new hybrid molecules (G1,G2, and G3) were synthesized via Sonogashira cross coupling and condensation reactions. Then, electrochemical activities and charge transfer resistances (Rct) of all prepared thymol-based catalysts were studied via cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively in 0.5 M glucose alkaline solution. Thymol based organic catalysts exhibited a good current density at around 0.1 mA.cm(-2) for the 2-isopropyl-5-methylphenyl 4-oxo-4-(5-(p-tolylethynyl)thiophen-2-yl)butanoate (G3). As a result, A new generation of ecologically friendly and alternative metal catalyst for direct glucose fuel cells is thymol derivatives-based catalyst..