Inorganic Chemistry Commons^™

Tuning Ion Mobility And Molecular Confinement In High-Performance Polymer Electrolytes For Energy Storage, Ezzeldien Yousef Muhammed Yousef

Theses and Dissertations

This research addresses the critical energy density limitations of aqueous supercapacitors, which are traditionally constrained by the narrow electrochemical stability window (ESW) of water 1.23 V. By employing two distinct molecular engineering strategies, this study developed high-performance electrolyte systems that significantly extend voltage stability and thermal resilience.

The first system, CsBr@PAM/HA, utilizes a polyacrylamide and hyaluronic acid hydrogel matrix. This system exploits the chaotropic nature of Cs⁺ ions to disrupt the aqueous hydrogen-bonding network, enhancing ionic conductivity to 104 mS cm^-1. Through systematic salt screening, CsBr was identified as the optimal electrolyte, enabling a stable 2.0 V …

Engineering Silicone Magnetic Fluids For Localized Radiation Attenuation During Ocular Melanoma Brachytherapy, Zachary L. Caprow

All Dissertations

Ocular melanoma is commonly treated using plaque brachytherapy; however, radiation-induced damage to healthy ocular tissues frequently results in partial or complete vision loss. This work investigates the development of an injectable, magnetically responsive silicone magnetic fluid designed to localize adjacent to the tumor and attenuate low-energy gamma radiation during treatment.

The material system consists of iron oxide nanoparticles surface-functionalized with a siloxane polymer, in which the nanoparticles provide magnetic responsiveness and radiation attenuation, while the polymer coating ensures colloidal stability, injectability, and biocompatibility. A one-pot synthetic approach was developed wherein a functionalized siloxane polymer containing iron-affinitive groups was reacted with …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …

Binary Solid/Liquid Equilibrium Of Mixtures Of Thermally Robust Salts And Molecular Compounds For Use As Heat Transfer Fluids, Jared Ridge Mathews

Honors Theses

Fossil fuels, contributors to climate change that may bear catastrophic consequences, power the entire world. The human species is almost entirely dependent on fossil fuels for energy, but other sources of renewable and environmentally friendly energy must be developed. Concentrated solar power (CSP) is a promising source of renewable energy with hampered potential—better heat transfer fluids (HTFs) are needed for it to be economically feasible. Currently, the HTFs in industrial use are predominantly either synthetic oils or nitrate-based molten salts. Synthetic oils are only stable up to 400 °C, and molten salts often have high melting temperatures, making them prone …

Effect Of Niobium Dopant On Zno Thin Films Prepared Via The Sol–Gel Spin Coating Method, Kevin Alvin Eswar, Nur Fairuz Rostan, Maryam Mohamad, Rabiatuladawiyah Md Akhir, Rosfayanti Rasmidi, Muliyadi Guliling, Najwa Ezira Azhar, Irmaizatussyehdany Buniyamin, Mohd Firdaus Malek, Mohamad Rusop Mahmood, Husairi Fadzilah Suhaimi, Saifollah Abdullah

Makara Journal of Science

Thin films of zinc oxide (ZnO) and niobium (Nb)-doped ZnO were deposited on a glass substrate using the sol–gel spin coating method. Diethanolamine, isopropyl alcohol, and zinc acetate served as the stabilizers, solvent, and starting ma-terial, respectively. Niobium pentachloride was employed as the dopant source. Energy-dispersive X-ray analysis con-firmed Nb incorporation. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and ultravio-let–visible spectroscopy (UV–Vis) analyses characterized the morphology, structure, and optics of the films, respective-ly. Both films, comprising nanoparticles, were visible in FESEM. Nb doping reduced the particle size from 44.2 nm to 35.8 nm. The XRD peaks at 31.23°, …

Amphiphilic Tripodal Metalloligands: Synthesis, Coordination Chemistry And Preliminary Catalysis, Austin W. Medley, Paul D. Miller, Craig A. Bayse, Robert D. Pike, Trandon A. Bender

Chemistry & Biochemistry Faculty Publications

Triscatecholate binding has been widely studied in the context of biological systems, supramolecular chemistry, and weak aggregate interactions. However, the utilization of the triscatecholate binding motif for the preparation of metalloligands remains unexplored. Herein, we report the synthesis, structural characterization, and functional studies of a triscatecholate ligand with an appended pyridyl residue as a candidate for such applications. Our findings reveal that the selective formation of cis-triscatecholate-based metalloligands is influenced by electronic effects on the catecholate anions, enabling the targeted synthesis of Al(III), Ga(III), and In(III) triscatecholate metalloligands capable of binding Zn(II) and Ru(II) at the appended pyridyl moiety for …

Engineering Multifunctional Silicon Nanostructures From Biorenewable Cellulose Nanocrystals, Nancy Chen

All Dissertations

The imperative search for alternative materials to address the pressing demand for advance energy storage is underscored by the escalating environmental predicaments. Lithium-ion batteries (LIBs) with graphite anodes have become the benchmark in energy storage; however, they are approaching a saturation point in terms of energy density. Silicon emerges as a promising contender to supplant graphite, owing to its profuse availability, cost-effectiveness, and impressive specific capacity of 4200 mAh g^-1. By integrating silicon anodes, LIBs stand to undergo a radical transformation, markedly diminishing in weight and size, thus heralding a novel wave of compact, lightweight energy storage systems. …

Mechanisms Of Dendritic Shorting In Lithium Metal Batteries With Li7la3zr2o12 Solid Electrolytes, Lukas Karapin-Springorum

Pomona Senior Theses

Energy storage will play a crucial role in efforts to mitigate the effects of climate change caused by greenhouse gas emissions from human activity. Lithium metal batteries using solid electrolytes like Li₇La₃Zr₂O₁₂ have higher energy density than lithium-ion batteries, which may enable a more rapid and complete electrification of transportation. However, lithium metal batteries suffer from undesirable short-circuiting when metallic lithium deposits connect the two electrodes. It has been debated whether these lithium dendrites generally grow directionally from the anode or are generated by the reduction of lithium ions inside the solid electrolyte, …

Processing, Stability, And High-Temperature Properties Of Doped Lacro3-Based Refractory Ceramics And Composites For Harsh Environments Sensing Applications, Javier A. Mena

Graduate Theses, Dissertations, and Problem Reports (ETD)

In order to test and monitor the operational stability and conditions of various energy, transportation, and manufacturing systems and their components, accurate sensors capable of operating at temperatures over 1000 °C in various environments for long durations are required. In addition, many of these harsh environmental systems do not permit sensors to be directly inserted into the environment, so the sensors need to be embedded into the surrounding support or thermal protective materials. Some technological and industrial applications that require the use of harsh environment conditions sensing include nuclear and chemical reactors, jet engines, heavyduty gas turbines, rotating bearings in …

Synthesis And Characterization Of Cobalt(Iii) Complexes And A Vanadium(Iv) Complex With Flavonoids As Ligands, Ethan Schroeder

Chemistry & Biochemistry Theses & Dissertations

For many years now, transition metal complexes have been used as favorable additional chemotherapeutic approaches to medicine that were previously unexplored in the literature. One well-known chemotherapeutic drug, cisplatin, has been applied, but is limited in use due to its toxicity to the cells and its undesirable side effects to humans. Newly developed cobalt-based complexes with ligands known as flavonoids are being used to fight cancer. Flavonoids, compounds mainly found in fruits and vegetables, are shown to have antioxidative and anticancer properties. Use of flavonoids as ligands in transition metal complexes, e.g., those with a Ru(II) metal center, have been …

The Study Of Corrosion On Additive-Manufactured Metals., Braydan Daniels

Electronic Theses and Dissertations

The purpose of this study was to investigate and compare the corrosion mechanisms between wrought and additive-manufactured (3D-printed) copper and stainless steel. The experimental procedure consisted of measuring the open circuit potential, electrochemical impedance spectroscopy, linear sweep voltammetry, Tafel analysis, surface topology, and scanning electron microscopy for each metal within salt water, tap water, sulfuric acid, and synthetic body fluid (excluding copper in synthetic body fluid).

Overall, printed stainless steel was more corrosion-resistant than wrought stainless steel in tap water and synthetic body fluid based on OCP, LSV, and surface topology results. Additionally, printed copper was more corrosion-resistant than wrought …

Exploration And Synthesis Of Half-Heusler And Disordered Ternary Intermetallic Single Crystals, Md Fahel Bin Noor

Graduate Theses/Dissertations

Due to their distinct physical and chemical characteristics, half-Heusler compounds are intermetallic materials that have undergone substantial research. The general formula for these compounds is XYZ, where X and Y are transition metals and Z is a p-block element. Thermoelectricity is among the half-Heusler compounds' most exciting potential uses, but additional possible applications include spintronics, magnetic refrigeration, and superconductivity, among others. Recently, half-Heuslers (and Heuslers) have emerged as candidates for catalysts for hydrogenation. The CoNbSn half-Heusler compound, as well as another unique intermetallic ternary compound, the disordered Mn_4-xCr_xAl₁₁, were successfully grown as single crystals …

Ambient Ammonia Synthesis Via Microwave-Catalytic Materials And Plasma Chemistry, Siobhan Brown

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ammonia is critical to supporting human life on earth because of its use as fertilizer. The Haber-Bosch process to produce ammonia has been practiced for over 100 years. This process operates at high pressure and temperature to overcome the thermodynamic and kinetic limitations of the ammonia synthesis reaction thus researchers have tried to overcome it for decades. At present this process represents 1% of global energy usage and 2.5% of global CO₂ emissions. The proposed chemical looping ammonia synthesis approach seeks to reduce the environmental impact of this critical process and to elucidate microwave-catalytic principles.

This research aims to …

Hierarchically Structured Photoelectrodes Via Atomic Layer Deposition, Justin Rowan Reed Demoulpied

Graduate Theses and Dissertations

In the search for a sustainable method to meet increasing energy needs, solar energy emerges as an underutilized, plentiful resource. Solar intermittency and requirements for transportation necessitate storing solar energy in the form of chemical bonds via artificial photosynthesis. Photoelectrochemical (PEC) water splitting generates hydrogen fuel from solar energy and water. A semiconducting material that successfully meets the complex requirements for building an industrially scalable PEC device has yet to emerge. This is leading to a reevaluation of materials previously overlooked within PEC research, mainly materials with limitations such as minimal charge carrier mobility and propensity to corrosion under illumination …

Improved Performance Of Silica-Supported La0.5Ba0.5Feo3 In The Reverse Water Gas Shift - Chemical Looping Process For Carbon Dioxide Reduction – A Density Functional Theory Study, Jiawei Guo

USF Tampa Graduate Theses and Dissertations

Global warming is increasingly obvious, and the reduction of greenhouse gases is an effective way to heal. Increasing the efficiency of catalysts that is applied in the industry can significantly reduce the emission of greenhouse gases. Reverse water gas shift chemical looping (RWGS-CL) is a promising reaction to convert CO2 to CO. La0.5Ba0.5FeO3 (LBF) is a good candidate for RWGS-CL, which shows increased conversion yield when supported on silica. This research focuses on identifying the mechanism of RWGS-CL via silica-supported LBF by exploring the oxygen vacancy formation energy (EO-vac). Density Functional Theory (DFT) is a powerful computational method to solve …

Structural, Charge Transport, Gas Sensing, Magnetic, Pseudocapacitive, And Electrocatalytic Properties Of Perovskite Oxides., Surendra Bahadur Karki

Electronic Theses and Dissertations

Perovskites are functional materials with the general formula ABO₃ (A = alkali, alkaline earth or lanthanoid cations and B = transition metal or main group cations). These materials are marked by a variety of crystal structures and interesting properties such as colossal magnetoresistance, ferroelectricity, multiferroicity, superconductivity, pseudocapacitance, gas sensing, charge transport, and electrocatalytic properties. The formula of perovskite can be written as AA’BB’O₆, when there is ordering between two cations over A and B-sites. Such compounds are called double perovskite oxides. Some amount of oxygen could be lost from crystal structure without decomposition of the phase. Such …

Modeling, Fabrication, And Characterization Of Rf-Based Passive Wireless Sensors Composed Of Refractory Semiconducting Ceramics For High Temperature Applications, Kavin Sivaneri Varadharajan Idhaiam

Graduate Theses, Dissertations, and Problem Reports (ETD)

Real-time health monitoring of high temperature systems (>500^oC) in harsh environments is necessary to prevent catastrophic events caused by structural failures, varying pressure, and chemical reactions. Conventional solid-state temperature sensors such as resistance temperature detectors (RTDs) and thermocouples are restricted by their operating environments, sensor dimensions and often require external power sources for their operation. The current work presents the research and development of RF-based passive wireless sensing technology targeting high temperatures and harsh environmental conditions. Passive wireless devices are generally classified as near-field and far-field devices based on the interrogation distance. Near-field sensors are placed at …

The Photophysical Studies Of Transition Metal Polyimines Encapsulated In Metal Organic Frameworks (Mof’S), Jacob M. Mayers

USF Tampa Graduate Theses and Dissertations

Light harvesting systems provide a platform that converts solar energy into other forms of energy. One of the most common examples of photon capturing and conversion into chemical energy is observed in photosynthetic organisms in both Eurkaroyic and Prokaryotic domains. Nature provides a model for successful light harvesting platforms which includes the compartmentalization of antenna complexes that contain separated donor and acceptor pairs that participate in efficient electron transfer processes. In order to mimic such systems, crystalline porous materials that exhibits regular cavities and pore dimensions provides an excellent starting place. Metal organic frameworks (MOFs) are a class of porous …

Multi-Level Analysis Of Atomic Layer Deposition Barrier Coatings On Additively Manufactured Plastics For High Vacuum Applications, Nupur Bihari

Dissertations, Master's Theses and Master's Reports

While hardware innovations in micro/nano electronics and photonics are heavily patented, the rise of the open-source movement has significantly shifted focus to the importance of obtaining low-cost, functional and easily modifiable research equipment. This thesis provides a foundation of open source development of equipment to aid in the micro/nano electronics and photonics fields.

First, the massive acceptance of the open source Arduino microcontroller has aided in the development of control systems with a wide variety of uses. Here it is used for the development of an open-source dual axis gimbal system. This system is used to characterize optoelectronic properties of …

Experimental Exploration Of Shared Magnetic Phases Between Diverse Systems Of Iron-Pnictide Superconductors, Ryan Scott Stadel

Graduate Research Theses & Dissertations

The exciting field of iron-pnictide superconductors offers unique opportunities for studying the relationship between magnetism and unconventional superconductivity. This is vital to developing an understanding of the microscopic origin of high-temperature superconductivity, which is itself an important step in harnessing such a potentially revolutionary technology.

Polycrystalline and crystalline samples are synthesized over a diverse collection of related iron-pnictide systems including (Ca,Sr,Ba)1-xNaxFe2As2, Ba(Fe1-xCox)2As2 (122s), and LaFeAs1-xPxO, and TbFeAs1-xPxO (1111s). These compounds are characterized through various types of neutron and x-ray diffraction on multiple instruments, as well as muon spin resonance, and magnetic susceptibility measurements.

A thorough investigation into the conditions under …

Study On Cation Exchange Of A Lead Coordination Polymer Targeting Dynamic Mixed Cation Doped And Mixed-Valent Coordination Polymers, Hamisu Aliyu Mohammed

Student Works (2020-2029)

Solid solution in Metal-Organic Coordination Polymers (MOCPs) is an emerging synthetic pathway for modifying chemical compositions and has been expansively investigated. It has been demonstrated to be an important tool for engineering novel functional materials that otherwise have not been synthesized via the conventional technique. Although stable solid material with variable functionalities and intriguing structural motifs could be engineered by judicious selection of multivariate metal centers and multifunctional ligands. However, solid solution featuring mixed valence in MOCP is rare. Motivated by the ability of Pb2+ to adopt range of coordination numbers (CN) and chemical environments (CE), in addition to its …

Synthesis Of Metal Oxide Surface And Interface Arrays By A Combined Solid-Liquid- Vapor/Vapor-Liquid-Solid Approach, Alexandra J. Riddle

Theses and Dissertations--Chemistry

This project was motivated by an in situ heating experiment in the transmission electron microscope (TEM) in which gold (Au) nanoparticles were observed to dissolve tin dioxide (SnO2) nanowires (NWs) under vacuum. The explanation for this observation was that the high-temperature and low-pressure environment of the TEM caused the reverse reaction of the well-known vapor-liquid-solid (VLS) method commonly used to grow NWs. In the VLS process, a metal catalyst absorbs reactant vapor until it becomes supersaturated. The precipitation of the NW occurs at the liquid-solid interface, which ceases when there is no longer reactant vapor, and the diameter of the …

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 …

Structure, Morphology And Composition-Property Elucidation Of Ni–Mo And Ni−Mo−P Nanocrystals For Water Splitting Reactions And Group Iv Alloy And Silicate Nanocrystals For Visible To Near Ir Optoelectronics, Ebtesam Hassan Abuelenein Eladgham

Theses and Dissertations

Abstract

Structure, Morphology and Composition-Property Elucidation of Ni–Mo and Ni−Mo−P Nanocrystals for Water Splitting Reactions and Group IV Alloy and Silicate Nanocrystals for Visible to Near IR Optoelectronics

by

Ebtesam Hassan Abuelenein Eladgham

A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University.

Advisor: Indika U Arachchige

Associate Professor, Department of Chemistry

Nanomaterials have gained a great attention because of their unique physical properties with size intermediate between molecular materials and extended solids. They have a large surface to volume ratio and display size tunable physical properties that was not …

Synthesis And Characterization Of Dielectric And Multiferroic Nanocrystalline Transition Metal Oxide Materials And Nanocomposites, Frederick A. Pearsall

Dissertations, Theses, and Capstone Projects

Nanocrystalline transition metal oxides with unique chemical, physical, magnetic and dielectric properties have very broad applications, ranging from photocatalysis, capacitor energy storage and 4-state memory. Frequency stable, high permittivity nanocomposite capacitors produced under mild processing conditions offer an attractive replacement to MLCCs derived from conventional ceramic firing. In one project reported herein, 0-3 nanocomposites were prepared using BaTiO₃ (barium titanate, BTO) nanocrystals, suspended in a poly(furfuryl alcohol) matrix, resulting in a stable, high effective permittivity, low and stable loss dielectric. Effective medium approximations were used to compare this with similar nanocomposite systems. The use of synthesized BTO nanocrystal photocatalysts …

Rare-Earth-Activated Group Vi D0 Metal Oxides As Thermosensitive Phosphors, Samarage Sameera Perera

Wayne State University Dissertations

ABSTRACT

RARE-EARTH-ACTIVATED GROUP VI d0 METAL OXIDES AS

THERMOSENSITIVE PHOSPHORS

by

SAMARAGE SAMEERA PRASAD PERERA

AUGUST 2019

Advisor: Dr. Federico A. Rabuffetti

Major: Chemistry

Degree: Doctor of Philosophy

Thermosensitive phosphors are solid-state materials that demonstrate distinct dependence of luminescence emission on temperature. These materials enable optical temperature sensing in environments where conventional thermometry is not possible (e.g., gas turbines, combustion engines, surface temperature distributions). However, the design of thermosensitive phosphors that show adequate sensitivity and low thermal quenching in the intermediate temperature range (i.e., 500–1000 K) remains challenging. This challenge can be addressed by understanding how to rationally manipulate the …

Synthesis And Adsorption Experiments With Metal-Organic Frameworks For High School And Undergraduate Laboratory Settings, Kate Holley

Legacy Theses & Dissertations (2009 - 2024)

Seven experiments are described and outlined here that introduce high school and undergraduate students to metal–organic frameworks (MOFs) and their applications. The experiments were designed to be completed with basic laboratory equipment and supplies and without the use of expensive characterization instruments, simulating typical high school chemistry laboratory conditions. Students synthesized two well-known MOFs, HKUST-1 and aluminum fumarate, using simple, safe, and rapid methods (fast enough to be performed within the time constrains of a typical high school class). Students then use their synthesized MOFs to explore their inherent sorption properties. In one set of experiments, the synthesized MOFs are …

Three-Dimensional Nanotube Arrays For Solar Energy Harvesting And Production Of Solar Fuels, Wipula P. R. Liyanage

Doctoral Dissertations

"Over the past decade extensive research has been carried out on photovoltaic semiconductors to provide a solution towards a renewable energy future. Fabricating high-efficiency photovoltaic devices largely rely on nanostructuring the photoabsorber layers due to the ability of improving photoabsorption, photocurrent generation and transport in nanometer scale. Vertically aligned, highly uniform nanorods and nanowire arrays for solar energy conversion have been explored as potential candidates for solar energy conversion and solar-fuel generation owing to their enhanced photoconversion efficiencies.

However, controlled fabrication of nanorod and especially nanotube arrays with uniform size and shape and a pre-determined distribution density is still a …

Metallic Systems At The Nano And Micro Scale: Bimetallic Nanoparticles As Catalysts And Mcraly Bond Coats In Thermal Barrier Coatings, Kenneth Kane

Theses and Dissertations

The dissertation is split into two parts. The first part will be focused on changes in material properties found at the nanoscale, as miscibility and electronic structure can change significantly with size. The formation of classically-immiscible bimetallic nanoparticles (BNPs) becomes favorable at the nanoscale and novel catalytic properties can emerge from the bimetallic alloying. The formation of alloyed and non-alloyed BNPs is achieved through pulse laser ablation (PLA) and a significant increase in catalytic activity is observed for both. Recently discovered, the increased activity in the non-alloyed BNPs, deemed multicomponent photocatalysis, is examined and the proposed mechanism discussed. The second …

Polyhedral Oligomeric Silsesquioxane-Phosphate Glass Matrix Nanocomposites With Additional Chapter On Phosphate Glass-Poly(Ethylene Terephthalate) Matrix Composites, Kyoungtae Kim

Dissertations

Preparation and characterization of tin fluorophosphate glass (Pglass) matrix nanocomposites incorporating polyhedral oligomeric silsesquioxane (POSS) were investigated on the structural, thermal, morphological, mechanical, and rheological properties. Various processes including synthesis, extrusion and sintering processes were applied to prepare the nanocomposite samples. Another application of POSS with hydrophobic functional groups on the well-structured nanoscale silicate cage with three silanol groups was investigated to present the feasibility to use POSS molecule as a coating material on the surface of the hydrophilic inorganic glass. In addition, Poly(ethylene terephthalate) polymer matrix composites incorporating Pglass was studied to present the benefits of the Pglass with …