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Full-Text Articles in Chemistry

Electrochemical Properties Of Mof-Derived Nickel Compounds For High-Performance Supercapacitors And Electrocatalysts, Shiva Bhardwaj May 2023

Electrochemical Properties Of Mof-Derived Nickel Compounds For High-Performance Supercapacitors And Electrocatalysts, Shiva Bhardwaj

Electronic Theses & Dissertations

There are various forms in which humans use energy in daily life. From applications that require a high energy density to long-term storage, the requirements for energy usage are diverse. Therefore, with the continuous increase in users worldwide, more practical energy-driven sources are required, allowing manufacturers to look toward emerging functional materials. An emerging class of functional porous materials referred to as metal-organic framework (MOF) has received considerable attention over the past two decades, partially because of their potential use in various applications, including gas storage, molecular separations, electrocatalyst, and energy devices. For example, metal oxide and hydroxide-based MOF materials …


Use Of Inner/Outer Sphere Terminology In Electrochemistry—A Hexacyanoferrate Ii/Iii Case Study, John Cassidy, Rafaela Cristina De Carvalho, Tony Betts Jan 2023

Use Of Inner/Outer Sphere Terminology In Electrochemistry—A Hexacyanoferrate Ii/Iii Case Study, John Cassidy, Rafaela Cristina De Carvalho, Tony Betts

Articles

Salts of hexacyanoferrate II/III anions have been widely used as redox couple probe molecules to determine the characteristics of electrode surfaces. Examples include the assessment of electrocatalysts for energy applications and electrocatalysts for the detection of biological or chemical species, as well as the determination of electrochemically active surface areas. An examination of the electrochemical literature, based largely on cyclic voltammetric investigations, reveals a wide range of peak separation and/or heterogeneous electron transfer rate constants, classified sometimes as inner or outer sphere electron transfer processes. Originally developed for the mechanistic interpretation of inorganic transition metal compounds in solution, this terminology …


Effect Of Microfluidic Channel Integration Onto Gold Microelectrode On Its Redox Electrochemistry, Ahmet Uçar, Zahraa Ali Hajool, Hamed Ghorbanpoor, Reza Didarian, Fatma Doğan Güzel Jan 2023

Effect Of Microfluidic Channel Integration Onto Gold Microelectrode On Its Redox Electrochemistry, Ahmet Uçar, Zahraa Ali Hajool, Hamed Ghorbanpoor, Reza Didarian, Fatma Doğan Güzel

Turkish Journal of Chemistry

Microfluidic systems have attracted significant interest in recent years as they are extensively employed in lab-on-chip and organ-on-chip research. Their combination with electrochemical platforms offers many advantages, promising a high potential for sensing applications, still the microfluidic-channel integration onto electrodes might induce challenges related to changes in signal-tonoise ratios and mass transport conditions. In this study, we investigated the effect of microfluidic channel integration in redox behavior of thermally deposited gold thin film microelectrodes by voltammetric (CV and SWV) electrochemical measurements. Using different dimensions of PDMS microfluidic channels (i.e. widths of 50, 100, 250, and 500 μm) and a constant …


Enhancing Vanadium Redox Battery Performance Using Tungsten-Bismuth-Based Oxide Nanostructures As Electrode Modifiers, Taher Al Najjar Jun 2022

Enhancing Vanadium Redox Battery Performance Using Tungsten-Bismuth-Based Oxide Nanostructures As Electrode Modifiers, Taher Al Najjar

Theses and Dissertations

Renewable energy power plants require high efficiency conversion and storage systems that can store high amounts of energy and can be integrated with the electrical grid. Vanadium redox flow batteries are very promising for this application. However, one major drawback of VRFBs is their low power density which means that right now they cannot replace non-renewable energy sources. Different carbon materials are used as electrodes in VRFBs and each carbon material affects the battery’s performance in a different way. Modification of these electrodes can increase the power density of the battery. Some metal oxides like tungsten oxide can enhance vanadium …


Nitro-Aromatic Polymers For Conversion-Style Battery Cathodic Materials, Brady P. Samuelson May 2022

Nitro-Aromatic Polymers For Conversion-Style Battery Cathodic Materials, Brady P. Samuelson

Honors Thesis

The development of organic electrode materials in rechargeable batteries has seen a resurgence in recent decades. This spike in interest is mostly due to the increased investments in renewable energy sources, grid-scale energy storage, and the rapid transition to electric vehicles. Current lithium battery cathode materials typically use some form of lithium metal oxide (specific capacity: 272 mAh g-1 which has problems with limited capacity, thermal runaway, and an unreliable supply chain. Our research group’s solution involves investigating new lightweight, organic redox groups combined with a conductive polymer backbone to serve as a possible replacement for the cathode in …


Study On Electrodeposition Of Antimony In Choline Chloride-Ethylene Glycol Eutectic Solvent, Hao Wang, Xiao-Zhou Cao, Xiang-Xin Xue Apr 2022

Study On Electrodeposition Of Antimony In Choline Chloride-Ethylene Glycol Eutectic Solvent, Hao Wang, Xiao-Zhou Cao, Xiang-Xin Xue

Journal of Electrochemistry

Antimony is a chemically stable metal that has been widely used in industry, military and other fields. The use of electrodeposition to prepare antimony coating has the advantages of simple operation and low cost. The deep eutectic solvent (DES) is a eutectic mixture composed of a hydrogen bond donor and a hydrogen bond acceptor at a fixed molar ratio. It has the advantages of wide electrochemical window, high thermal stability, easy preparation, and low cost. Selecting DES as the electrolyte for electrodeposition can avoid the hydrogen evolution reaction of the aqueous system and the toxicity of ionic liquids. In recent …


New Bis-Isoxazole With Monoterpenic Skeleton: Regioselective Synthesis, Spectroscopicinvestigation, Electrochemical, And Density Functional Theory (Dft) Studies, Ali Oubella, Meryem Hrimla, Mouhi Eddine Hachim, Mourad Fawzi, Abdoullah Bimoussa, Lahoucine Bahsis, Aziz Boutouil, Aziz Auhmani, Abdelkhalek Riahi, My Youssef Ait Itto Jan 2022

New Bis-Isoxazole With Monoterpenic Skeleton: Regioselective Synthesis, Spectroscopicinvestigation, Electrochemical, And Density Functional Theory (Dft) Studies, Ali Oubella, Meryem Hrimla, Mouhi Eddine Hachim, Mourad Fawzi, Abdoullah Bimoussa, Lahoucine Bahsis, Aziz Boutouil, Aziz Auhmani, Abdelkhalek Riahi, My Youssef Ait Itto

Turkish Journal of Chemistry

A novel bis-isoxazole was synthesized from (R)-Carvone and p-methylbenzaldoxime, via two successive [3+2] cycloaddition reactions (32CA). The newly obtained bis-isoxazole has been fully characterized by HRMS and NMR spectroscopy. The HMBC experiment was performed to determine the stereo and the regioselectivity of the reaction. The electrochemical behavior of the studied compound, in oxidation and reduction processes, was examined using the cyclic voltammetry technique. In addition, the regioselectivity of the [3+2] cycloaddition reaction and the molecular structure of the title compound was performed by density functional theory (DFT). The HOMO and LUMO orbitals were investigated to determine the electronic properties of …


Insight Into Electrochemical Degradation Of Cartap (In Padan 95sp) By Boron-Doped Diamond Electrode: Kinetic And Effect Of Water Matrices, Hoang Nguyen Jan 2022

Insight Into Electrochemical Degradation Of Cartap (In Padan 95sp) By Boron-Doped Diamond Electrode: Kinetic And Effect Of Water Matrices, Hoang Nguyen

Turkish Journal of Chemistry

In this work, the kinetic electrochemical degradation of Cartap (CT) (in Padan 95 SP) at boron-doped diamond (BDD) electrode was investigated. This study indicated that the degradation of CT underwent both direct and indirect oxidations. Water matrices can either accelerate or inhibit the removal efficiency of CT: adding 15 mM Cl- improved kCT from 0.039 min-1 to 0.054 min-1 (increased by 38%), while kCT decreased by 61.5% and 64% when increasing the concentration of HCO3- and humic acid (HA) to 15 mM and 15 mg L-1, respectively. CT degradation was inhibited …


Cyclic Voltammetric Simulations On Batteries With Porous Electrodes, Xue-Fan Cai, Sheng Sun Dec 2021

Cyclic Voltammetric Simulations On Batteries With Porous Electrodes, Xue-Fan Cai, Sheng Sun

Journal of Electrochemistry

Lithium-ion batteries (LIBs) are among the most widely used energy storage devices. Whole-cell modeling and simulations of LIBs can optimize the design of batteries with lower costs and higher speeds. The Pseudo-Two-Dimensional (P2D) electrochemical model is among the most famous whole-cell models and widely applied in LIB simulations. P2D model consists of a series of kinetic equations to model Li+/Li diffusion in working/counter electrodes and electrolytes, which are filled in the porous electrodes and separator, and reactions at the interface of electrolyte and active particles. The traditional applications of P2D model, however, are limited to the cases where the current …


Detection Of Gold Cysteine Thiolate Complexes On Gold Nanoparticles With Time-Of-Flight Secondary Ion Mass Spectrometry, Yolanda Hedberg, Jonas Hedberg, Valentin Romanovski, Elena Romanovskaia, Heng-Yong Nie Apr 2021

Detection Of Gold Cysteine Thiolate Complexes On Gold Nanoparticles With Time-Of-Flight Secondary Ion Mass Spectrometry, Yolanda Hedberg, Jonas Hedberg, Valentin Romanovski, Elena Romanovskaia, Heng-Yong Nie

Chemistry Publications

Gold (Au) nanoparticles (NPs) are widely used in nanomedical applications as a carrier for molecules designed for different functionalities. Previous findings suggested that biological molecules, including amino acids, could contribute to the dissolution of Au NPs in physiological environments and that this phenomenon was size-dependent. We, therefore, investigated the interactions of L-cysteine with 5-nm Au NPs by means of time-of-flight secondary ion mass spectrometry (ToF-SIMS). This was achieved by loading Au NPs on a clean aluminum (Al) foil and immersing it in an aqueous solution containing L-cysteine. Upon rinsing off the excessive cysteine molecules, ToF-SIMS confirmed the formation of gold …


Investigation Of Electrochemical Behavior Of Potassium Ferricyanide/Ferrocyanide Redox Probes On Screen Printed Carbon Electrode Through Cyclic Voltammetry And Electrochemical Impedance Spectroscopy, Yücel Koç, Uğur Morali, Sali̇m Erol, Hüseyi̇n Avci Jan 2021

Investigation Of Electrochemical Behavior Of Potassium Ferricyanide/Ferrocyanide Redox Probes On Screen Printed Carbon Electrode Through Cyclic Voltammetry And Electrochemical Impedance Spectroscopy, Yücel Koç, Uğur Morali, Sali̇m Erol, Hüseyi̇n Avci

Turkish Journal of Chemistry

Potassium ferricyanide, potassium ferrocyanide, and their combination system are widely used redox probes for electrochemical impedance spectroscopy (EIS) characterization. In this work, electrochemical behavior of K3Fe(CN)6, K4Fe(CN) 6, and K3Fe(CN)6/K4Fe(CN)6 redox probes at five different concentrations using a screen printed carbon electrode (SPCE) by cyclic voltammetry (CV) and EIS methods was analyzed. Redox potentials were observed as a result of anodic and cathodic peak with CV analysis with determination 10 mM appropriate concentration through 0.01 mM, 0.1 mM, 1 mM, and 100 mM. In addition, with EIS analysis, each redox probe was simulated according to two different Randles circuit models …


Novel Nonperipheral Octa-3-Hydroxypropylthio Substituted Metallo-Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Electrochemical, Photochemical And Computational Properties, Ni̇lgün Kabay, Yasemi̇n Bayğu, Meti̇n Ak, İzzet Kara, Esra Nur Kaya, Mahmut Durmuş, Yaşar Gök Jan 2021

Novel Nonperipheral Octa-3-Hydroxypropylthio Substituted Metallo-Phthalocyanines: Synthesis, Characterization, And Investigation Of Their Electrochemical, Photochemical And Computational Properties, Ni̇lgün Kabay, Yasemi̇n Bayğu, Meti̇n Ak, İzzet Kara, Esra Nur Kaya, Mahmut Durmuş, Yaşar Gök

Turkish Journal of Chemistry

The current study describes the synthesis, electrochemical, computational, and photochemical properties of octa (3-hydroxypropylthio) substituted cobalt (II) (4), copper (II) (5), nickel (II) (6) and zinc(II) (7) phthalocyanine derivatives. These novel compounds were characterized by elemental analysis, 1H, 13C NMR, FT-IR, UV-Vis, and MS. The redox behaviors of these metallo-phthalocyanines were investigated by the cyclic voltammetric method. The optimized molecular structure and gauge-including atomic orbital (GIAO) 1H and 13C NMR chemical shift values of these phthalocyanines in the ground state had been calculated by using B3LYP/6-31G(d,p) basis set. The outcomes of the optimized molecular structure were given and compared with …


Low Loaded Pt-Co Catalyst Surfaces Optimized By Magnetron Sputtering Sequentialdeposition Technique For Pem Fuel Cell Applications: Physical And Electrochemicalanalysis On Carbon Paper Support, Osman Öztürk, Aydin Haşi̇moğlu, Oğuz Kaan Özdemi̇r, İnci̇ Karaaslan, Ali̇ Şems Ahsen Jan 2021

Low Loaded Pt-Co Catalyst Surfaces Optimized By Magnetron Sputtering Sequentialdeposition Technique For Pem Fuel Cell Applications: Physical And Electrochemicalanalysis On Carbon Paper Support, Osman Öztürk, Aydin Haşi̇moğlu, Oğuz Kaan Özdemi̇r, İnci̇ Karaaslan, Ali̇ Şems Ahsen

Turkish Journal of Chemistry

A series of thin Pt-Co films with different metal ratios were deposited by using the sequential cosputtering directly on a commercial hydrophobic carbon paper substrate at room temperature and in ultra-high vacuum (UHV) conditions. Their electrocatalytic properties toward the oxygen reduction reaction were investigated in 0.5 M H2SO4 solution by means of cyclic voltammetry (CV) and linear sweep voltammetry (LSV) on rotating disc electrode (RDE). The results showed that Pt particles, deposited by dc-magnetron gun, surround the large Co-clusters deposited by rf-magnetron gun. In addition, the increase of Co content led to an increase in the electrochemical active surface area …


Electrochemical Determination Of Dopamine Based On Metal-Substituted Polyoxometalates Composites, Yi-Fei Xing, Na Li, Xiao-Fang Wen, Hong-Yan Han, Min Cui, Cong Zhang, Ju-Jie Ren, Xue-Ping Ji Dec 2020

Electrochemical Determination Of Dopamine Based On Metal-Substituted Polyoxometalates Composites, Yi-Fei Xing, Na Li, Xiao-Fang Wen, Hong-Yan Han, Min Cui, Cong Zhang, Ju-Jie Ren, Xue-Ping Ji

Journal of Electrochemistry

In this report, a dopamine electrochemical sensor based on metal-substituted polyoxometalates and reduced graphene oxide (RGO) composite was successfully constructed. The K2H2SiW11NiO39·xH2O (SiW11Ni) was synthesized by hydrothermal method, while the RGO was prepared by Hummers' method and chemical reduction method. The above-mentioned materials were characterized by SEM, FTIR and XRD. The as-synthesized SiW11Ni and RGO composites were modified on the surface of glassy carbon electrode (GCE) by drop coating method, and the sensing interface (SiW11Ni-RGO/GCE) was successfully constructed. The electrochemical properties of …


Electrochemical Oxidation Of Metal Chromium In Odium Hydroxide Aqueous Solution, Ping Han, Hai-Tao Feng, Ya-Ping Dong, Sen Tian, Bo Zhang, Wu Li Jun 2020

Electrochemical Oxidation Of Metal Chromium In Odium Hydroxide Aqueous Solution, Ping Han, Hai-Tao Feng, Ya-Ping Dong, Sen Tian, Bo Zhang, Wu Li

Journal of Electrochemistry

Ferrochrome electrolysis technology is a novel method for preparing sodium chromate (Na2CrO4). Although the method performs well at soft reaction conditions, controllable process, environmentally friendly production process, etc., the electrochemical oxidation process of metal chromium in NaOH aqueous electrolyte is still unclear. At present, there are few research articles about specific electrochemical oxidation of metal chromium in NaOH aqueous electrolyte. It is, therefore, meaningful to carry out the research in electrochemical oxidation mechanism of chromium. The electrochemical oxidation of metal chromium in 0.01 mol·L-1 ~ 10 mol·L-1 NaOH aqueous electrolytes at 20 °C was studied by …


Fabrication, Characterization And Applications Of Chemically Modified Planar Metallic Electrodes From Copper Clad Sheets, Rana T. K. Alsaidi Jun 2020

Fabrication, Characterization And Applications Of Chemically Modified Planar Metallic Electrodes From Copper Clad Sheets, Rana T. K. Alsaidi

Theses

In this work, we developed a fabricating method for planar electrodes by milling and cutting copper-clad sheets. The main objectives of this thesis are to produce customized planar electrodes with different geometries with relatively higher reusability compared to the screen-printed electrodes available by commercial vendors. The fabricated electrodes from copper-clad sheets were electroplated with different metals using commercial electroplating baths to produce different metallic planar electrodes. Also, the fabrication of planar electrodes with cavities to be filled with modified carbon paste was done. The electroplated planar electrodes were characterized by the cyclic voltammetry technique. In addition to that, they were …


Cyclic Voltammetry Coupled With Faradic Adsorption/Desorption Processes: A Finite Element Simulation, Jia-Yao Guo, Duan Chen, Jie Zhang, Dong-Ping Zhan Apr 2020

Cyclic Voltammetry Coupled With Faradic Adsorption/Desorption Processes: A Finite Element Simulation, Jia-Yao Guo, Duan Chen, Jie Zhang, Dong-Ping Zhan

Journal of Electrochemistry

Heterogeneous electron transfer (HET) coupled with Faradic adsorption/desorption is the fundamental processes involved in hydrogen evolution reaction, oxygen reduction reaction, carbon dioxide reduction reaction, and methanol oxidation reaction. However, the electrochemical behaviors of HET coupled with Faradic adsorption/desorption are complicated, and difficult to get the interface reaction kinetics quantitatively. In this paper, finite element method was adopted to simulate the cyclic voltammetric behaviors of HET coupled with Faradic adsorption/desorption processes by using the Fick’s second law and Langmuir isotherm. The cyclic voltammograms when reactant or product adsorbed weakly or strongly were simulated, and they agreed well with the classical results. …


Investigation Of Glucose Oxidation At Gold Nanoparticles Deposited At Carbon Nanotubes Modified Glassy Carbon Electrode By Theoretical And Experimental Methods., Farhat Saira, Humaira Razzaq, Misbah Mumtaz, Safeer Ahmad, Muhammad Aftab Rafiq, Azra Yaqub, Nabiha Dilshad, Ayesha Ihsan, Muhammad Masood Ul Hasan Mar 2020

Investigation Of Glucose Oxidation At Gold Nanoparticles Deposited At Carbon Nanotubes Modified Glassy Carbon Electrode By Theoretical And Experimental Methods., Farhat Saira, Humaira Razzaq, Misbah Mumtaz, Safeer Ahmad, Muhammad Aftab Rafiq, Azra Yaqub, Nabiha Dilshad, Ayesha Ihsan, Muhammad Masood Ul Hasan

Karbala International Journal of Modern Science

In the current research work, AuNPs-CNTs nanocomposite was synthesized chemically and decoration of AuNPs on the surface of MWCNTs was confirmed by UV-Vis, SEM and XPS analysis. Synthesized nanocomposite was utilized for its application towards non-enzymatic glucose sensing by modifying glassy carbon electrode with nanocomposite employing electrochemical techniques. In addition, theoretical calculations were performed by Density Functional Theory (DFT), employing B3YLP with basis set 6- 311+G(d,p) in gaseous phase and LANL2DZ basis set. Both theoretical and experimental results predicted Au-CNTs composite as a better candidate for glucose oxidation as compared to CNTs and AuNPs alone, owing to the synergistic effect …


Synthesis, Optical, And Structural Properties Of Bisphenol-Bridgedaromatic Cyclic Phosphazenes, Bünyemi̇n Çoşut, Burcu Topaloğlu Aksoy, Süreyya Oğuz Tümay, Ahmet Şenocak, Serkan Yeşi̇lot Jan 2020

Synthesis, Optical, And Structural Properties Of Bisphenol-Bridgedaromatic Cyclic Phosphazenes, Bünyemi̇n Çoşut, Burcu Topaloğlu Aksoy, Süreyya Oğuz Tümay, Ahmet Şenocak, Serkan Yeşi̇lot

Turkish Journal of Chemistry

Phenoxy- and naphthoxy-substituted bisphenol-bridged cyclic phosphazenes were synthesized in 2 steps and their thermal, photophysical, and electrochemical properties were investigated. The structures of the cyclic phosphazene compounds were determined by ESI-MS mass spectrometry and $^{1}$H, $^{13}$C, and $^{31}$P NMR spectroscopies. The photophysical studies of phenoxy- and naphthoxy-substituted bridged cyclophosphazenes were investigated by means of absorption and fluorescence spectroscopies in different solvents. Thermal and electrochemical properties of the target compounds were also studied. Furthermore, the excimer emissions through intramolecular interactions in solution and in solid state were investigated by fluorescence spectroscopy and the theoretical calculations were performed in detail using DFT.


Transient Electrochemical Surface-Enhanced Raman Spectroscopic Study In Electrochemical Reduction Of P-Nitrothiophenol, Yun Ling, Jing Tang, Guo-Kun Liu, Cheng Zong Dec 2019

Transient Electrochemical Surface-Enhanced Raman Spectroscopic Study In Electrochemical Reduction Of P-Nitrothiophenol, Yun Ling, Jing Tang, Guo-Kun Liu, Cheng Zong

Journal of Electrochemistry

P-nitrothiophenol (PNTP) is one of the most common probe molecules studied by surface-enhanced Raman spectroscopy (SERS). The research in electrochemical reduction behavior of PNTP will help understanding the mechanism for the nitrobenzene reduction. In this paper, we used transient electrochemical surface-enhanced Raman spectroscopy (TEC-SERS) to study the SERS of PNTP with cyclic voltammetry and chronoamperometry on gold electrodes. The results show that the TEC-SERS provide a time resolution that equals the transient electrochemical methods, and we concluded that the reaction was so quick that we did not observe the spectral information of intermediate species described in the literatures with a …


Electrochemical Behaviors Of Azopurine On Gold Electrodes, Ming-Xue Li, Hang Shi, Jia Liu, Meng Zhang, Jian-Zhang Zhou, De-Yin Wu, Zhong-Qun Tian Dec 2019

Electrochemical Behaviors Of Azopurine On Gold Electrodes, Ming-Xue Li, Hang Shi, Jia Liu, Meng Zhang, Jian-Zhang Zhou, De-Yin Wu, Zhong-Qun Tian

Journal of Electrochemistry

In this paper, we studied the electrochemical behaviors of azopurine on polished gold electrodes with cyclic voltammetry (CV). On the basis of analyzing scan rate and peak current, it was supposed that the redox process belonged to a reversible process controlled by adsorption in 0.2 mol·L-1 PBS (pH = 4.0 ~ 10.0) solutions. The potentials of redox peaks moved more negatively with increasing pH value. This proved that the H+ proton has participcted in the electrochemical reaction. The further data analysis and the calculation of surface adsorption excess demonstrated that the reaction was a two-proton and two-electron process. …


Bis(Tetra­Phenyl­Arsonium) Hexa­Fluorido­Technetate(Iv) Dihydrate: Preparation, Structure And Spectroscopic Analysis, Samundeeswari Mariappan Balasekaran, Frederic Poineau Nov 2019

Bis(Tetra­Phenyl­Arsonium) Hexa­Fluorido­Technetate(Iv) Dihydrate: Preparation, Structure And Spectroscopic Analysis, Samundeeswari Mariappan Balasekaran, Frederic Poineau

Chemistry and Biochemistry Faculty Research

Reports of quadrivalent transition-metal fluoride salts containing bulky organic cations are limited. In this context, we prepared the bis­(tetra­phenyl­arsonium) hexa­fluorido­technetate(IV) dihydrate salt, (C24H20As)2[TcF6]·2H2O, by a cation metathesis reaction of (NH4)2[TcF6] in water. This is the first report of an arsonium salt of the hexa­fluorido­technetate(IV) dianion. (AsPh4)2[TcF6]·2H2O crystallizes in the triclinic space group P[\overline{1}]. The [TcF6]2− anion adopts a slightly distorted octa­hedral geometry with an average Tc—F bond length of 1.933 Å. The cyclic voltammogram of (AsPh4)2[TcF6]·2H2O in CH3CN shows a one-electron reversible oxidation wave at 1.496 V.


Experimental And Computational Electrochemistry Of Quinazolinespirohexadienone Molecular Switches – Differential Electrochromic Vs Photochromic Behavior, Eric W. Webb, Jonathan P. Moerdyk, Kyndra B. Sluiter, Benjamin J. Pollock, Amy L. Speelman, Eugene J. Lynch, William F. Polik, Jason G. Gillmore Oct 2019

Experimental And Computational Electrochemistry Of Quinazolinespirohexadienone Molecular Switches – Differential Electrochromic Vs Photochromic Behavior, Eric W. Webb, Jonathan P. Moerdyk, Kyndra B. Sluiter, Benjamin J. Pollock, Amy L. Speelman, Eugene J. Lynch, William F. Polik, Jason G. Gillmore

Faculty Publications

Our undergraduate research group has long focused on the preparation and investigation of electron-deficient analogs of the perimidinespirohexadienone (PSHD) family of photochromic molecular switches for potential application as "photochromic photooxidants" for gating sensitivity to photoinduced charge transfer. We previously reported the photochemistry of two closely related and more reducible quinazolinespirohexadienones (QSHDs), wherein the naphthalene of the PSHD is replaced with a quinoline. In the present work, we report our investigation of the electrochemistry of these asymmetric QSHDs. In addition to the short wavelength and photochromic long-wavelength isomers, we have found that a second, distinct long-wavelength isomer is produced electrochemically. This …


Supercapacitors With Gate Electrodes, Tazima Selim Chowdhury May 2019

Supercapacitors With Gate Electrodes, Tazima Selim Chowdhury

Dissertations

A new approach to improve the capacitance of supercapacitors (SC) is proposed in this study. A typical SC is composed of an anode and a cathode; a separator in between them assures an unintentional discharge of the capacitor. The study focuses on a family of structured separators, either electronically active or passive which are called gates. An active structured separator layer has been fabricated and analyzed. The structured separator has characteristics of electrical diode and is fabricated out of functionalized carbon nanotubes (CNT). Improvement of the overall capacitance of SC, equipped with either active or passive structured separators demonstrated a …


Examining Electrochemical Properties Of O-Quinone And Sulfur Adducts Using Bisphenol A-3,4-Quinone Platform, Barbara Mullen May 2019

Examining Electrochemical Properties Of O-Quinone And Sulfur Adducts Using Bisphenol A-3,4-Quinone Platform, Barbara Mullen

Theses/Capstones/Creative Projects

o-Quinones are toxic electrophiles that can disrupt cellular macromolecules. Whether endogenous or xenobiotic, o-quinones are reactive compounds that are difficult to isolate. This work uses the o-quinone of bisphenol(BPA), bisphenol A-3,4-quinone(BPAQ), which can be efficiently synthesized and isolated, to study the electrochemical properties of o-quinones and their sulfur adducts in order to understand their metabolic fate. Cyclic voltammetry and equilibrium analysis were used to determine the relative oxidation potential of the BPA catechol and adducts, formed by reacting glutathione(GSH) and N-acetylcysteine(NAC) with BPAQ. BPAQ-sulfur adducts with 5-position substitution displayed lower oxidation potentials when compared to the …


Surface Immobilization Of Terpyridine Compounds, Elizabeth Hallett May 2019

Surface Immobilization Of Terpyridine Compounds, Elizabeth Hallett

Chemical Engineering Undergraduate Honors Theses

The deoxydehydration (DODH) of polyols to alkenes is a promising method of producing high-value chemical feedstocks from biomass-derived materials. Current catalytic systems for DODH require the use of costly reducing agents that generate stoichiometric amounts of chemical waste. Immobilizing catalysts on electrode surfaces using chemical linking groups eliminates the need for sacrificial reductants. In this work, glassy carbon electrodes were modified with 4’-(3,4-dihydroxyphenyl)-2,2’:6’,2’’-terpyridine to investigate o-benzoquinone as a potential linking group for DODH, and possibly for other reactions. Previous studies involving electrodes modified with quinone-containing compounds have primarily been focused on catalyzing the oxidation of NADH; the nature or …


Electrochemical Oxidation Of Curcuminoids: An Experimental And Computational Investigation, Zeynep Kalaycioğlu, Nurgül Karadaş, Mehmet Emi̇n Çinar, Si̇bel Ayşil Özkan, Duri̇şehvar Özer Ünal, Ayşegül Gölcü, Fatma Bedi̇a Eri̇m Jan 2019

Electrochemical Oxidation Of Curcuminoids: An Experimental And Computational Investigation, Zeynep Kalaycioğlu, Nurgül Karadaş, Mehmet Emi̇n Çinar, Si̇bel Ayşil Özkan, Duri̇şehvar Özer Ünal, Ayşegül Gölcü, Fatma Bedi̇a Eri̇m

Turkish Journal of Chemistry

Curcuminoids, reported to have important biological properties, such as antioxidant, anti-Alzheimer, and antidiabetic properties, comprise curcumin (CRM; 1,7-bis [4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) and its derivatives demethoxycurcumin (DMC; (E,6E)-1-(3,4-dimethoxy-cyclohexyl)-7-(3,4-dimethoxyphenyl)hepta-1,6-diene-3,5-dione) and bisdemethoxycurcumin (BDMC; 1,7-bis[4-hydroxyphenyl]-1,6-heptadiene-3,5-dione). Their electrochemical oxidations are thoroughly explored by applying cyclic and differential pulse voltammetric techniques. The dependence of current intensities and potentials on pH, concentration, scan rate, and nature of the buffer was investigated. The outcome is supported by density functional theory computations indicating the transfer of 4-e$^{-}$/H$^{+}$, 6-e$^{-}$/H$^{+}$, and 8-e$^{-}$/H$^{+}$ couples involved in the oxidation mechanisms of CRM, DMC, and BDMC, respectively, leading to the formation of the same oxidized product.


In Silico And In Vitro Evaluation Of The Biological Activity Of Some Organic Sulfur-Containing Compounds, Victoria Osipova, Maria Polovinkina, Anastasia Osipova, Yulia Gracheva, Andrey Okhlobystin Jan 2019

In Silico And In Vitro Evaluation Of The Biological Activity Of Some Organic Sulfur-Containing Compounds, Victoria Osipova, Maria Polovinkina, Anastasia Osipova, Yulia Gracheva, Andrey Okhlobystin

Turkish Journal of Chemistry

It was predicted, using the Prediction of Activity Spectra for Substances online software, that organic sulfur-containing compounds 2,6-di-tert-butyl-4-mercaptophenol (1), 2,6-di-tert-butyl-4-(3-mercaptopropyl)phenol (2), bis-3-[3,5-di-tert-butyl-4-hydroxyphenyl)propyl] sulfide (3), bis(3,5-di-tert- butyl-4-hydroxyphenyl) disulfide (4), diphenyl disulfide (5), dibenzyl disulfide (6), dibutyl disulfide (7), di-tert-butyl disulfide (8), diallyl disulfide (9), and methyl propyl trisulfide (10) could possess antioxidant activity and act as active scavengers of oxygen metabolites. The antiradical activity of these species was analyzed and it was shown that they were able to react with electrochemically generated the superoxide anion radical. The rate constants for reactions of 1-10 with the superoxide anion radical were calculated. The …


Amperometric Urea Biosensor Based On Immobilized Urease On Polypyrrole And Macroporous Polypyrrole Modified Pt Electrode, Maliheh Hosseinian, Ghasem Najafpour, Ahmad Rahimpour Jan 2019

Amperometric Urea Biosensor Based On Immobilized Urease On Polypyrrole And Macroporous Polypyrrole Modified Pt Electrode, Maliheh Hosseinian, Ghasem Najafpour, Ahmad Rahimpour

Turkish Journal of Chemistry

Biosensing of urea by a biosensor as a direct detection method at ambient temperature and pressure instead of chromatography leads to a significant reduction in processing costs. Amperometric biosensors based on urease immobilization on macroporous polypyrrole (MPPy) and pyrrole on the surface of a Pt electrode were developed. Applying cyclic voltammetry (CV), we demonstrated the synthesis of MPPy using monodispersed polystyrene spheres (460 nm) as a template. CV and chronoamperometric studies were conducted to evaluate the electrochemical current of the modified electrodes. For the electrode with polypyrrole (PPy), the biosensor response was linear in the range of 1.67--8.32 mM (R$^{2}$ …


Electrodeposition Of Cobalt From Eutectic-Based Ionic Liquid, Rostom Ali M., Sankar Saha S, Ziaur Rahman Md Oct 2018

Electrodeposition Of Cobalt From Eutectic-Based Ionic Liquid, Rostom Ali M., Sankar Saha S, Ziaur Rahman Md

Journal of Electrochemistry

The electrodeposition of cobalt from a solution containing cobalt chloride in either a urea-choline chloride based or an ethylene glycol (EG)-choline chloride based ionic liquid has been carried out onto copper and steel cathodes by constant current and constant potential methods at different temperatures. The influences of various experimental conditions on electrodeposition and morphology of the deposited layers have been investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD)technique. It has been shown that the smooth, shiny with good adherence and bright metallic coloured cobalt coatings were obtained from both urea and EG based ionic liquids at the applied …