Chemistry Commons^™

Electrochemistry Of Bubbles: Developing New Sensors, Promoting Gas Evolution Reactions, And Extraction Of Rare Earth Elements, Ruchiranga R. Ranaweera

Wayne State University Dissertations

This dissertation presents new analytical, electrocatalysis, and separation strategies that utilize bubble behaviors in different electrochemical systems. The first part of this dissertation focuses on the method development for PFAS preconcentration and detection. First, we present the bubble-nucleation-based electrochemical method for the selective and sensitive detection of surfactants. Our method utilizes the high surface activity of surfactant analytes to affect the electrochemical bubble nucleation and then transduces the change in nucleation condition to an electrochemical signal for determining the surfactant concentration. Using this method, we demonstrate the quantitation of perfluorinated surfactants in water, a group of emerging environmental contaminants, with …

Electrochemical And Mass Spectrometry Methods For Identification Of Gunshot Residues (Gsr) In Forensic Investigations, Kourtney A. Dalzell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Gun violence continues to be one of most significant challenges straining the USA society causing thousands of human lives lost every year. In 2020 alone, firearm-related incidents including homicide, accidents, and suicides, reached a staggering number of over 43,000.^1,2 With the increase in these types of incidents, several service areas in crime laboratories are heavily impacted by the number of cases run on a yearly basis. These include firearm examinations, gunshot residue (GSR) analysis, bullet hole identification, and shooting distance determination, which are crucial to support a criminal investigation and, overall, the justice system in our country. These areas …

Analysis Of Forensically Relevant Evidence Using Electrochemistry, Spectroscopy, And Mass Spectrometry Tools, Colby Edward Ott

Graduate Theses, Dissertations, and Problem Reports (ETD)

Forensic science relies on the use of multiple techniques in the assessment of evidence to increase the accuracy and reliability of the results. However, with the rapidly changing drug landscape due to the introduction of novel psychoactive substances, many traditional screening methods are no longer sensitive or selective enough for use. Additionally, many screening methods such as chemical color tests are prone to false positive and negative results and are subjective. Therefore, the goal of this dissertation was to develop a novel analytical scheme that can provide a more efficient, rapid, and sensitive method that will facilitate adoption in the …

Electrodeless Electrochemistry Enabled By Nonthermal Plasma, Harold Oldham

McKelvey School of Engineering Graduate Student Theses & Dissertations

The increasing availability and decreasing cost of electricity generated by renewable resources have motivated research into electrified chemical processing, whereby electrical energy is used to drive chemical transformations. Electricity-intensive processing techniques such as electrochemistry using solid electrodes has attracted attention in this context for the synthesis of organic compounds, such as high-value pharmaceuticals and renewable chemical production. Selective chemical transformations are achieved in conventional aqueous electrochemical systems by using external circuitry to bias solid electrodes, allowing for the preferential transfer of electrons between the electrode-liquid interface. Despite having the ability to promote controlled electrochemical reactions, configurations using solid electrodes are …

Electrochemical Studies Of Organic And Organometallic Compounds In The Pursuit Of Electrocatalytic Carbon Dioxide Reduction, Joshua J. Ludtke

College of Science and Health Theses and Dissertations

Carbon dioxide is the main contributor to the greenhouse effect in the world today; developing renewable energy sources and addressing anthropogenic CO₂ release into the atmosphere are two key ways of addressing its increasing impact. Electrocatalytic reduction to products like methanol or carbon monoxide is one useful path to address the rapid increase of carbon dioxide, and the fac-M(bpy-R)(CO)₃X family of complexes (M = Mn or Re; bpy-R = substituted 2,2’-bipyridine; X = Cl, Br, etc.) is one class of effective CO₂ reduction catalysts. Although the capability of the rhenium complex Re(PyBimH)(CO)₃Cl (PyBimH …

Electrochemical Studies Of Poly 3-(4-Methoxyphenyl)[5] Ferrocenophane-1,5-Dimethylene And Copolymers With Styrene And N-Phenylmaleimide, Niyati Arora

Electronic Theses & Dissertations

Ferrocene is an organometallic compound in which an iron atom is sandwiched between two cyclopentadienyl rings. Ferrocene containing polymers receive a considerable amount of research because of their known chemistry, stable redox reactions and useful electrical systems. Noteworthy are their uses as electrode coatings, electro-catalysts and as an anode in battery applications. In this research, the synthesis and polymerization of a ferrocenophane diene is reported. Using a Wittig reaction 3-(4-methoxyphenyl)[5]ferrocenophane-1,5-dimethylene was synthesized from 3-(4-methoxyphenyl)[5]ferrocenophane-1,5-dione. The homopolymer and copolymers with styrene and N-phenylmaleimide were synthesized via free radical polymerization from 3-(4-methoxyphenyl)[5]ferrocenophane-1,5-dimethylene using AIBN as the initiator. These polymers were characterized using …

The Emerging Applications Of Sulfur (Vi) Fluorides In Catalysis, Nicholas Ball, Cayo Lee, Jonathan E. Elisabeth, Nathan C. Friede, Glenn M. Sammis

Pomona Faculty Publications and Research

The past decade has witnessed remarkable growth of catalytic transformations in organic sulfur(VI) fluoride chemistry. This Perspective concentrates exclusively on foundational examples that utilize catalytic strategies to synthesize and react S(VI) fluorides. Key mechanistic studies that aim to provide insight toward future catalytic systems are emphasized.

Exploring The Mechanism Of The Electrostatic Denaturation Of Double-Stranded Dna, Gayatri Raghu

Master's Theses

Electrostatic melting is an electrochemical tool that can be used to analyze the stability of DNA, allowing for the detection of various mutations in double-stranded DNA (dsDNA). Here, we explore the influence of electrostatic double layer formation on the unzipping of dsDNA to better comprehend the mechanism of this process. Previous studies by our lab show that the melting curve produced can distinguish between fully complementary 34-bp strands and a version of the same sequence in which one base pair has been replaced with a mismatch pair or detect and characterize the crosslinking of the dsDNA by anticancer drug cisplatin. …

Electrochemical Oxidation Of Individual Silver Nanoparticles: Exploring The Effect Of Particle Shape, Capping Ligand, Electrolyte, And Potential On The Signal, Jazlynn Sikes

Graduate Theses and Dissertations

Nanomaterials have revolutionized science and technology. Their unique properties can be exploited, and nanoparticles are being used as catalysts, antimicrobials, drug delivery vehicles, sensors, and more. However, the fundamental properties of nanomaterials and their interactions with their surrounding environments are still poorly understood. In this work, a single-particle approach was used to observe the effects of capping ligand, surrounding solution, and particle shape on the oxidative process to gain deeper understanding of silver nanoparticle properties. When allowed the opportunity, the particles will adsorb to the electrode surface then oxidize in rapid succession upon electrode activation, regardless of capping ligand as …

Renewable Energy Conversion: Organic Redox Flow Batteries And Electrocatalytic Carbon Dioxide Reduction, Camden R. Debruler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Steadily increasing global energy demands have pushed the industry to investigate renewable energy sources like solar and wind to help alleviate the strain on fossil fuel based non-renewable energy sources while also reducing carbon emissions. However, the energy producing power of these renewable technologies is limited by factors such as weather and the day-night cycle. Additional energy storage technologies are needed which are capable of storing excess energy during periods of high productivity, and delivering it when production rates fluctuate.

Batteries represent one possible energy storage device to meet this need. Specifically, redox flow batteries (RFBs) offer advantages in terms …

Synthesis And Conductivity Analysis Of A Methyl (Polyethylene Glycol) Comb Polymer, Olivia Fox

Honors Theses

The overall goal of work in this field is to improve materials for use in a variety of applications in fuel cell and battery production. This thesis specifically investigates the synthesis of two variations of a methyl (polyethylene glycol) comb polymer electrolyte (MePEG_nwhere n=7) to understand how the molecular structure of an ion-conducting polymer affects its electrochemical properties. The MePEG used in this synthesis contains seven ethylene glycol groups and was added to a poly (methylhydrosiloxane) comb polymer backbone. In the first sample, the polymer contained only the MePEG sidechain, and in the second sample, the polymer contained …

Alternative View Of Oxygen Reduction On Porous Carbon Electrocatalysts: The Substance Of Complex Oxygen-Surface Interactions, Giacomo De Falco, Marc Florent, Jacek Jagiello, Yongqiang Cheng, Luke L. Daemen, Anibal J. Ramirez-Cuesta, Teresa J. Bandosz

Publications and Research

Electrochemical oxygen reduction reaction (ORR) is an important energy-related process requiring alternative catalysts to expensive platinum-based ones. Although recently some advancements in carbon catalysts have been reported, there is still a lack of understanding which surface features might enhance their efficiency for ORR. Through a detailed study of oxygen adsorption on carbon molecular sieves and using inelastic neutron scattering, we demonstrated here that the extent of oxygen adsorption/interactions with surface is an important parameter affecting ORR. It was found that both the strength of O2 physical adsorption in small pores and its specific interactions with surface ether functionalities in the …

Developing Methods For Diversifying Molecular Scaffolds Directly On A Microelectrode Array, Nai-Hua Yeh

Arts & Sciences Graduate Student Theses and Dissertations

Microelectrode arrays contain collections of spatially isolated electrodes that can be individually addressed. Thus, the arrays have the potential to support synthesis of molecular libraries if unique members of the library can be located next to unique electrodes in the array. The result would be an intriguing platform for screening the molecules in the library against biological receptors in order to identify high-affinity ligands for those targets, especially since the arrays themselves can be directly used in the signaling studies. To expand the capabilities of the arrays, the goal of this thesis is to develop the new array chemistry needed …

Synthesis Of Nonperipherally Tetra-[5-(Diethylamino)-2-Formylphenoxy] Substituted Metallophthalocyanines And Their Electrochemistry, Turgut Keleş, Di̇lek Ünlüer, Zekeri̇ya Biyiklioğlu, Yasemi̇n Ünver

Turkish Journal of Chemistry

3-[5-(diethylamino)-2-formylphenoxy]phthalonitrile (n-TY-CN), metallophthalocyanines n-TY-Co, n-TY-Cu, and n-TY-Mn bearing [5-(diethylamino)-2-formylphenoxy] groups at nonperipheral positions were prepared for the first time. These compounds were characterized with IR, NMR (only for n-TY-CN), mass and UV-vis (except n-TY-CN) spectroscopy. Voltammetric characterizations of n-TY-Co, n-TY-Cu, and n-TY-Mn revealed that while n-TY-Co, n-TY-Cu, and n-TY-Mn showed characteristic Pc ring and/or metal-based reduction reaction, n-TY-Co, n-TY-Cu, and n-TY-Mn were coated on the working electrode during the oxidation processes owing to the cationic electropolymerizations of the [5-(diethylamino)-2-formylphenoxy] substituents.

Enhanced Electrochemical And Light-Driven Co2 Reduction By Incoporating Pendant Functionality In The Second-Coordination Sphere Of Molecular Catalysts, Sayontani Sinha Roy

Electronic Theses and Dissertations

With the increase in global population and rapid industrialization, a gigantic amount of greenhouse gases is being released into the atmosphere each year. The catastrophic effect of these accumulated greenhouse gases is driving global climate change and adversely impacting our ecosystem. Popularizing the traditional renewable energy sources (such as solar and wind energy) can mitigate the problem by cutting down anthropogenic CO2 emissions, which is the major contributor to this global problem. However, the intermittent nature of these energy sources is problematic to reliably power society throughout the year. Therefore, converting CO2 to various value-added chemicals with the aid of …

Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao

Dissertations

Mass spectrometry (MS) has been growing as one of the most widely used tools in the field of analytical chemistry. Various applications have been developed to harness the high sensitivity and specificity of mass spectrometric analysis. In this dissertation, two major challenges are addressed. By developing mass spectrometric-based methods, absolute quantitation of proteins/peptides have been achieved. Elucidation of various reaction mechanisms are also enabled. These are the focuses of this dissertation.

In Chapters 2 to 4, a novel quantitation method is developed, titled as coulometric mass spectrometry (CMS). The strength of this method is that no reference standard or isotope-labeled …

The Utilization Of Metal-Ligand Cooperativity For Electrocatalytic Reduction And Catalytic Hydration., Steven Cronin

Electronic Theses and Dissertations

Small molecules are building blocks for developing larger materials. These small molecules could be extremely small, such as hydrogen, or larger such as a nitrile, but their impact on the global economy is massive. This dissertation describes a catalyst for three reactions involving small molecules; 1) the hydrogen evolution reaction, 2) the carbon dioxide reduction reaction, 3) nitrile hydration. The catalyst Zn(DMTH) (DMTH = diacetyl-2-(4-methyl-3-thiosemicarbazonate)-3-(2-pyridinehydrazonato)) use “metal-ligand cooperativity” between the Lewis acid Zn(II) metal ion and an uncoordinated Lewis base nitrogen in the ligand framework to activate substrates. The complex has been analyzed via NMR, UV/Vis, single crystal X-ray crystallography, …

Potential Application Of Ionic Liquids For Electrodeposition Of The Material Targets For Production Of Diagnostic Radioisotopes, Maciej Chotkowski, Damian Połomski, Kenneth Czerwinski

Chemistry and Biochemistry Faculty Research

An overview of the reported electrochemistry studies on the chemistry of the element for targets for isotope production in ionic liquids (ILs) is provided. The majority of investigations have been dedicated to two aspects of the reactive element chemistry. The first part of this review presents description of the cyclotron targets properties, especially physicochemical characterization of irradiated elements. The second part is devoted to description of the electrodeposition procedures leading to obtain elements or their alloys coatings (e.g., nickel, uranium) as the targets for cyclotron and reactor generation of the radioisotopes. This review provides an evaluation of the role ILs …

Electrostatic Denaturation Of Dna-Cisplatin Adducts, Eddie Madrigal

Master's Theses

In this thesis, electrochemical approaches are used to determine the properties of deoxyribonucleic acid (DNA) by electrostatic denaturation. The electrochemical routine involves an application of a destabilization potential, an equilibration potential, and a square wave voltammogram (SWV) to monitor the extent of melting. Our method uses a monolayer consisting of thiol modified DNA and mercaptohexanol on a gold electrode. These electrodes are then incubated in a complementary sequence tagged with methylene blue. By using our electrostatic denaturation technique, different parameters are explored, such as surface densities, surface coverages, and ionic strengths. As proof of concept, these techniques were applied toward …

Mxenes As Flow Electrodes For Capacitive Deionization Of Wastewater, Naqsh E. Mansoor

Boise State University Theses and Dissertations

The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to …

Elucidation Of Radical Cation Trapping Chemistry: Using Electrochemical And Photochemical Techniques To Qualitatively Assess The Kinetics Behind Anodic Oxidative Cyclizations, Luisalberto Gonzalez

Arts & Sciences Graduate Student Theses and Dissertations

While the field of organic chemistry has grown throughout the decades, its primary concern has always been on the generation, conversion, and study of molecular structures. Within that philosophy, the development of new reactions affords chemists the ability to overcome previous synthetic barriers or develop more elegant and simple synthetic routes to difficult-to-construct molecules. Within that realm, electrochemistry is seeing increased attention due its ability to generate highly reactive intermediates, recycle chemical reagents, and reverse the polarity of known functional groups. One example of such an application is the use of electrochemistry to form radical cations. While radical cations have …

Electrochemical Reduction Of Carbon Dioxide And Carbon Monoxide For The Production Of Green Fuels And Chemicals., Jacob M. Strain

Electronic Theses and Dissertations

It has become apparent that closing the carbon cycle on this planet in order to mitigate disastrous consequences of runaway global warming has become one of the most pressing issues of our civilization. One of the ways we need to accomplish this goal is by finding news methods to generate fuels that will be carbon neutral. Renewable fuels and green chemicals will be a major component of closing the carbon cycle and restoring our planet’s ecosystem into a sense of balance. A method that can help achieve this goal is the reduction of CO₂. If CO₂ can …

Electrochemical Nitrogen Reduction To Ammonia Using Molybdenum Disulfide-Based Nanocatalysts, Assem Omar M Basurrah

Theses and Dissertations

Ammonia is the basis for producing fertilizers for food production. The Haber-Bosch process is the main method to produce ammonia. Because of the energy and environmental problems associated with the Haber-Bosch process, extensive research is being explored for other ammonia production methods, including electrochemical methods based on nitrogen reduction reaction (NRR). In this thesis, molybdenum disulfide nanocatalysts (~4 nm) on carbon fibers were synthesized by hydrothermal reactions. The resulting composites were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the composites were measured by using linear sweep voltammetry, cyclic voltammetry, and controlled potential …

Investigation Of Underpotential Deposition Of Copper At Heated Gold Loop Screen-Printed Electrodes In A Variety Of Water Samples, Eun-Ju Lee

Legacy Theses & Dissertations (2009 - 2024)

To study the underpotential deposition (UPD) of copper, three different types of water samples (TraceSelect® Ultra-pure water, Indian pond water at University at Albany and tap water) are used at a heated gold loop screen-printed electrode (GLE), which is a new type of heated working electrode for voltammetry measurements that is able to directly detect the copper content in the water samples. The anodic stripping analysis of copper is performed with these gold loop electrodes at room temperature of 25 °C and electrode temperature of 80 °C at two different deposition potentials, -0.20 V and +0.10 V. Furthermore, the concentration …

Electrolytic Oxidative Coupling Of Alcohols With Aldehydes To Form Esters, Katherine L. Verboom

Honors College Theses

There are copious amounts of naturally occurring and synthetic esters known that have a wide range of applications in industry to produce fine chemicals. Traditional methods of ester synthesis involve a reaction between a carboxylic acid and an alcohol in the presence of a Bronsted acid catalyst. The primary objective of this research project was to carry out the ester synthesis using the electrochemical coupling of aldehydes with alcohols instead of with a Bronsted acid catalyst because the electrochemical coupling would be an all-around better alternative of ester synthesis than the traditional method of using the catalyst. Electrochemistry has long …

Structural Annotation Of Electro- And Photochemically Generated Transformation Products Of Moxidectin Using High-Resolution Mass Spectrometry, Lisa Kotthoff, Sarah-Louise O'Callaghan, Jan Lisec, Tanja Schwerdtle, Matthias Koch

Articles

Moxidectin (MOX) is a widely used anthelmintic drug for the treatment of internal and external parasites in food-producing and companion animals. Transformation products (TPs) of MOX, formed through metabolic degradation or acid hydrolysis, may pose a potential environmental risk, but only few were identified so far. In this study, we therefore systematically characterized electro- and photochemically generated MOX TPs using high-resolution mass spectrometry (HRMS). Oxidative electrochemical (EC) TPs were generated in an electrochemical reactor and photochemical (PC) TPs by irradiation with UV-C light. Subsequent HRMS measurements were performed to identify accurate masses and deduce occurring modification reactions of derived TPs …

Multi-Component Material For Solar Energy Conversion And Fundamentals Of Lead Acid Batteries, Crystal Ferels

Graduate Research Theses & Dissertations

Synthesis of complex inorganic materials is desirable because their complex composition allows more degrees of freedom and tunability, whose properties differ from their parent components. As an expansion on this concept, we synthesized a quinary compound Ce3FeWS3O6, using a molten flux method and a solvothermal method. The compound crystallizes into a hexagonal crystal system with space group P63/m. Its electric partition shows an anion with the form [(Ce3+)3W6+(S2-)3(O2-)6]3- forcing the transition metal Fe3+ state and leaving no conduction electrons, making the material a semiconductor. This compound is the right candidate as photoelectric material capable of absorbing photons from the solar …

Transition Metal Chalcogenide Hybrid Systems As Catalysts For Energy Conversion And Biosensing, Siddesh Umapathi

Doctoral Dissertations

"Generation of hydrogen and oxygen through catalyst-aided water splitting which has immense applications in metal air batteries, PEM fuel cells and solar to fuel energy production, has been one of the critical topics in recent times. The state of art oxygen evolution reaction (OER), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER) catalysts are mostly comprised of precious metals. The current challenge lies in replacing these precious metal-based catalysts with non-precious earth-abundant materials without compromising catalytic efficiency.

This research explores mixed metal selenides containing Fe-Ni, Fe-Co and RhSe which were hydrothermally synthesized and/or electrodeposited and tested for OER and ORR …

An Electrochemical Instrument For The Analysis Of Heavy Metals In Water Via Anodic Stripping Coulometry For Applications In Remote Sensing., Kelsey Lynn Kaht

Electronic Theses and Dissertations

From the high levels of arsenic in groundwater in Bangladesh to the lead contamination of drinking water in Flint, Michigan, there are incidents across the globe that highlight the need for a reliable instrument capable of monitoring heavy metals remotely and continuously in a variety of geographical locations. Typical instrumentation for water analysis, such as ICP and AAS, must be housed in a central lab and relies on an operator traveling to the collection site, obtaining a sample, and transporting it back to the lab. This analysis provides a snapshot of the water quality that is limited to the specific …

Convective Instabilities Derived From Dissipation Of Chemical Energy, Reuben H. Simoyi, Matthew W. Eskew

Chemistry Faculty Publications and Presentations

Oxidation reactions of a series of organosulfur compounds by chlorite are excitable, autocatalytic, and exothermic and generate a lateral instability upon being triggered by the autocatalyst. This article reports on the convective instabilities derived from the reaction of chlorite and thiourea in a Hele-Shaw cell. Reagent concentrations used for the development of convective instabilities delivered a temperature jump at the wave front of 2.1 K. The reaction zone was 2 mm and due to normal cooling after the wave front, this induced a spike rather than the standard well-studied front propagation. Localized spatiotemporal patterns develop around the wave front. This …