Chemistry Commons^™

Structural And Magnetic Properties Of Molecular Beam Epitaxy (Mnsb2te4)X(Sb2te3)1−X Topological Materials With Exceedingly High Curie Temperature, Candice R. Forrester, Christophe Testelin, Kaushini Wickramasinghe, Ido Levy, Dominique Demaille, David Hrabovsky, Xiaxin Ding, Lisa Krusin-Elbaum, Gustavo Lopez, Maria C. Tamargo

Publications and Research

Tuning the properties of magnetic topological materials is of interest to realize exotic physical phenomena, new quantum phases and quasiparticles, and topological spintronic devices. However, current topological materials exhibit Curie temperature (T_C) values far below those needed for practical applications. In recent years, significant progress has been made to control and optimize T_C, particularly through defect-engineering of these structures. Most recently, we reported T_C values up to 80 K for (MnSb₂Te₄)_x(Sb₂Te₃)_1−x when 0.7 ≤ x ≤ 0.85 by controlling the composition x and the …

Effect Of Annealing On Photoluminescence From Defects In Gan, Oleksandr Andrieiev

Theses and Dissertations

Annealing is a critical process in modern GaN technology, essential for achieving p-type conductivity by activating the Mg_Ga acceptor, as first demonstrated by Shuji Nakamura in the early 1990s. Despite the omnipresence of hydrogen as an impurity in GaN crystals, the precise mechanisms governing hydrogen diffusion and acceptor passivation remain only partially understood. The presented research investigates the effects of annealing-induced activation and hydrogen passivation on C and Be acceptors in GaN grown by MOCVD, HVPE, and MBE methods. We explored these effects by using several annealing techniques, gas compositions, and thermal regimes. A transient behavior between the C …

Electrospun Pt-Tio₂ Nanofibers Doped With Hpa For Catalytic Hydrodeoxygenation, Amos Taiswa, Randy L. Maglinao, Jessica M. Andriolo, Sandeep Kumar, Jack L. Skinner

Civil & Environmental Engineering Faculty Publications

Electrospinning is utilized to fabricate catalytic nanofiber scaffold for biocrude upgrading in hydrodeoxygenation (HDO) following computational studies suggesting the need for nano-catalysts for efficient HDO conversion and selectivity. Here, Pt-TiO₂ nanofibers are fabricated through electrospinning, followed by wet impregnation with a heteropoly acid (HPA), tungstosilicic acid. Intensive heat treatments were incorporated during and after processes to obtain a HPA doped Pt-TiO₂ nano-catalyst. Catalytic HDO was performed in a batch reactor with phenol as the raw biocrude dissolved in hexadecane. The HPA doped Pt-TiO₂ catalyst demonstrated promising HDO performance of 37.2% conversion and a 78.9% selectivity to oxygen …

Nitrogen-Doped Graphite Felt On The Performance Of Aqueous Quinone-Based Redox Flow Batteries, Heng Zhang, Li-Xing Xia, Shan Jiang, Fu-Zhi Wang, Zhan-Ao Tan

Journal of Electrochemistry

Modification of electrode is vitally important for achieving high energy efficiency in aqueous quinone-based redox flow batteries (AQRFBs). The modification of graphite felt (GF) was carried out by means of urea hydrothermal reaction, and simultaneously, the effects of hydrothermal reaction time on the functional groups and surface structure of nitrogen-doped graphite felt were studied. The surface morphology and defect, element content and surface chemical state of the modified electrode were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) test, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The electrochemical performance of the modified electrodes was evaluated by cyclic voltammetry, electrochemical impedance …

Electrochemical Performance Of Porous Ceramic Supported Tubular Solid Oxide Electrolysis Cell, Heng-Ji Wang, Wen-Guo Chen, Zhou-Yi Quan, Kai Zhao, Yi-Fei Sun, Min Chen, Ogenko Volodymyr

Journal of Electrochemistry

Solid oxide electrolysis cell (SOEC) is an efficient and clean energy conversion technology that can utilize electricity obtained from renewable resources, such as solar, wind, and geothermal energy to electrolyze water and produce hydrogen. The conversion of abundant intermittent energy to hydrogen energy would facilitate the efficient utilization of energy resources. SOEC is an all-ceramic electrochemical cell that operates in the intermediate to high temperature range of 500–750 ℃. Compared with traditional low temperature electrolysis technology (e.g., alkaline or proton exchange membrane cells operating at ~100 ℃), the high-temperature SOEC can increase the electrolysis efficiency from 80% to ~100%, providing …

An In-Situ Raman Spectroscopic Study On The Interfacial Process Of Carbonate-Based Electrolyte On Nanostructured Silver Electrode, Yu Gu, Yuan-Fei Hu, Wei-Wei Wang, En-Ming You, Shuai Tang, Jian-Jia Su, Jun Yi, Jia-Wei Yan, Zhong-Qun Tian, Bing-Wei Mao

Journal of Electrochemistry

The solid-electrolyte interphase (SEI) plays a key role in anodes for rechargeable lithium-based battery technologies. However, a thorough understanding in the mechanisms of SEI formation and evolution remains a major challenge, hindering the rapid development and wide applications of Li-based batteries. Here, we devise a borrowing surface-enhanced Raman scattering (SERS) activity strategy by utilizing a size optimized Ag nanosubstrate to in-situ monitor the formation and evolution of SEI, as well as its structure and chemistry in an ethylene carbonate-based electrolyte. To ensure a reliable in-situ SERS investigation, we designed a strict air-tight Raman cell with a three-electrode configuration. Based on …

Combined Risk Based Inspection And Fault Tree Analysis For Repetitive 3-Phase Line Piping Leakage At West Java Offshore Topside Facility, Dona Yuliati, Akhmad Herman Yuwono, D. Rizal Asral, Donanta Dhaneswara

Journal of Materials Exploration and Findings

Hydrocarbon releases might result in serious consequences in various aspects. In addition to the contribution to environmental pollution, repetitive leakages need high repair costs. This study aim is to minimize potential repetitive leakage for other typical 3-phase piping systems. We conducted the risk assessment by adopting Risk Based Inspection (RBI) API 581 to identify risk level, calculating piping lifetime, recommended inspection plan and mitigations. The most relevant root causes can be obtained through quantitative Fault Tree Analysis (FTA). Observation and investigation was taken from eight 3-phase piping systems that experienced repetitive leakages. It has been found that the risk level …

Nitrogen Gas Quenching Pressure Effect On Bs S155 Alloy Steel In Vacuum Furnace, Agus Mulyadi Hasanudin, Eddy Sumarno Siradj

Journal of Materials Exploration and Findings

The production of metal and alloy products requires the use of heat treatment, when during the heat treatment process, quenching is a crucial step. The quenching medium can be anything from water, a salt bath, oil, air and gas. In a vacuum furnace, pressurized gas, most frequently nitrogen (N₂) gas, serves as one of the quenching mediums. One of the drawbacks of the quenching process is the distortion and dimensional change of the parts. This paper aims to investigate the influence of nitrogen gas quenching pressure on the distortion and dimensional change of aerospace actuator gear planet parts …

Microplate-Like Metal Pyrophosphate Engineered On Ni-Foam Towards Multifunctional Electrode Material For Energy Conversion And Storage, Rishabh Srivastava

Electronic Theses & Dissertations

High clean energy demand, dire need for sustainable development, and low carbon footprints are the few intuitive challenges, leading researchers to aim for research and development for high-performance energy devices. The development of materials used in energy devices is currently focused on enhancing the performance, electronic properties, and durability of devices. Tunning the attributes of transition metals using pyrophosphate (P₂O₇) ligand moieties can be a promising approach to meet the requirements of energy devices such as water electrolyzers and supercapacitors, although such a material’s configuration is rarely exposed for this purpose of study.

Herein, we grow …

Ionically Crosslinked Cellulose Nanocrystals By Metal Nitrates For The Preparation Of Stable Emulsions With Tunable Interface Properties, Joseph Batta-Mpouma, Gurshagan Kandhola, Jin-Woo Kim

Materials Science and Engineering Faculty Publications and Presentations

Biologically extracted cellulose nanocrystals (CNCs) are rod-like and amphiphilic materials with surface-exposed (hydrophilic sites) and hidden (hydrophobic sites) hydroxyl groups. These physicochemical characteristics make CNCs suitable for use as emulsifying agents to stabilize emulsions. Stable oil-in-water emulsions, using sulfated (i.e., – SO₃−) CNCs that were ionically crosslinked with alkaline-earth (i.e., Mg ²⁺) or transition-d-block (i.e., Zn ²⁺) metal cations, were developed without the use of any synthetic surfactants or prior functionalization of pure CNCs with hydrophobic molecules. Various emulsion surface properties such as interfacial tension, surface charge, surface chemistry, as well as rheology were characterized. Ionically …

Computationally-Driven Insights Into The Ligand Environments Of Materials For Catalysis And Separations, Stephen Vicchio

All Dissertations

Designing new catalytic and sorption materials is necessary to limit global temperature rise below 1.5 ◦C by 2050, while also meeting global energy demands. Climate change and energy production are not mutually exclusive; global population growth has direct impacts on global energy demands and climate. In both catalysis and adsorption applications, new technologies are needed to address these challenges. Catalysis can provide alternate, low-energy routes for converting low-value gases into higher-value chemical commodities, thus altering our current energy production. Likewise, new sorption materials can capture previously emitted CO₂ from decades of energy production from fossil fuels, thus helping to …

Niobate Nanosheet Catalysts For Cationic Dye Intercalation And Solar-Driven Water Photolysis, Cassandra Idona Monárrez-Grendahl

Open Access Theses & Dissertations

With the goal of creating efficient visible light photocatalysts for water photolysis, in this work we are exploring the synthesis of new porous oxide materials derived from potassium triniobate (KNb3O8) and titanium niobium oxide (KTiNbO5), which are layered wide band gap semiconductors. Generating hydrogen via direct water photolysis holds promise as a way to lower the cost of hydrogen gas production so it can be used as a renewable and clean alternative fuel. My group has demonstrated that layered semiconductor materials have the potential to enable the synthesis of new types of photocatalyst composites with customizable characteristics. In this work, …

Deficiency Of Acute-Phase Serum Amyloid A Exacerbates Sepsis-Induced Mortality And Lung Injury In Mice, Ailing Ji, Andrea C. Trumbauer, Victoria P. Noffsinger, Luke W. Meredith, Brittany Dong, Qian Wang, Ling Guo, Xiangan Li, Frederick C. De Beer, Nancy R. Webb, Lisa R. Tannock, Marlene E. Starr, Christopher M. Waters, Preetha Shridas

Saha Cardiovascular Research Center Faculty Publications

Serum amyloid A (SAA) is a family of proteins, the plasma levels of which may increase >1000-fold in acute inflammatory states. We investigated the role of SAA in sepsis using mice deficient in all three acute-phase SAA isoforms (SAA-TKO). SAA deficiency significantly increased mortality rates in the three experimental sepsis mouse models: cecal ligation and puncture (CLP), cecal slurry (CS) injection, and lipopolysaccharide (LPS) treatments. SAA-TKO mice had exacerbated lung pathology compared to wild-type (WT) mice after CLP. A bulk RNA sequencing performed on lung tissues excised 24 h after CLP indicated significant enrichment in the expression of genes associated …

Enhancing Urban Water Quality Through Biological-Chemical Treatment: Aquatic Macroinvertebrate Community And Temporal Chlorophyll-A Response, Matthew Chaffee

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

With a growing human population, urbanization is impeding a plethora of natural waterways. Of these, urban ponds play a vital role in nutrient sequestration, flood prevention, and habitat sanctuaries. However, nutrient loading can reduce habitat effectiveness and promote harmful algae blooms. To reduce internal nutrient loads, a biological-chemical treatment strategy consisting of floating treatment wetlands (FTWs) and lanthanum were applied to two urban retention ponds, Densmore and Wilderness Ridge Ponds. To measure effectiveness, chlorophyll-a samples were collected and correlated with Sentinel-2. A novel band algorithm termed 3BR1 produced a strong correlation (R² = 0.72) to physical chlorophyll-a …

Upcyclying Of Polyethylene Terephtalate By Addition Of Thermoplastic Elastomer, Diego Francisco Bermudez

Open Access Theses & Dissertations

Continual overconsumption of single-use plastics has generated challenges of solid waste management across the United States. Common plastic waste management solutions, such as landfill, have caused the migration of contaminants into the environment consequently affecting not only the health of wildlife, but also that of human beings. Alternative strategies for the handling of single-use plastic such as polyethylene terephthalate (PET), used in the food packaging industry, can ultimately help mitigate the noxious consequences of single-use plastics affecting entire ecosystems. This study demonstrates a potential avenue of materials upcycling by studying the effects of coupling PET with the thermoplastic elastomer styrene-ethylene-butylene-styrene …

Characterization Of Interlayer Laser Shock Peening During Fused Filament Fabrication Of Polylactic Acid (Pla), Fabien Denise

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The field of additive manufacturing (AM) has gained a significant amount of popularity due to the increasing need for more sustainable manufacturing techniques and the adaptive development of complex product geometries. The problem is that AM parts routinely exhibit flaws or weaknesses that affect functionality or performance. Over the years, surface treatments have been developed to compensate certain flaws or weaknesses in manufactured products. Combining surface treatments with the modularity of additive manufacturing could lead to more adaptable and creative improvements of product functions in the future. The current work evaluates the feasibility of pursuing a new research axis in …

Lif-Sn Composite Modification Layer To Modify Garnet/Lithium Metal Interface, Wu Yang, Xue-Fan Zheng, Yu-Qi Wu, Zheng-Liang Gong

Journal of Electrochemistry

The growing demands for electric vehicles and consumer electronics; as well as the expanding renewable energy storage market; have promoted extensive research on energy storage technologies with low costhigh energy density and safety. Lithium (Li) metal and solid-state electrolytes are considered as important components for next-generation batteries because of their great potential for improvements in energy density and safety performance. Inorganic garnet-type solid electrolytes with high Li-ion conductivity (about 10^-3 S·cm^-1) and high shear modulus (55 GPa) are considered to be ideal solid-state electrolytes; however; the issue of Li dendrite growth still obstructs their practical application. Herein; …

Preparation And Lithium Storage Properties Of Carbon Confined Li3Vo4 Nano Materials, Jia-Qi Fan, Huan-Qiao Song, Jia-Ying An, Amantai A-Yi-Da-Na, Mo Chen

Journal of Electrochemistry

Li₃VO₄, as a promising anode material for lithium ion batteries, has been widely studied because of its low and safe voltage, and large capacity. However, its poor electronic conductivity impedes the practical application of Li₃VO₄ particularly at high rates. In this paper, carbon confined Li₃VO₄ nano materials (Li₃VO₄/C) were synthesized by hydrothermal and solid-phase method, and for comparison, the Li₃VO₄ (N) nano materials without carbon confinement and Li₃VO₄ (B) materials were also synthesized by pure solid-phase method. The composition, structure, …

Peg-Water Electrolyte For High-Performance Zinc Iodine Dual-Ion Batteries, Xiao-Feng Qu, Yu-Ting Tang, Xin-Cheng He, Jia-Sheng Zhou, Zi-Heng Tang, Wen-Hua Feng, Jun Liu

Journal of Electrochemistry

Thanks to abundant resource and rapid redox reaction kinetics, iodine is regarded as promising positive materials inthe batteries. However, the shuttling effect due to the high solubility of iodine in the electrolyte makes the performance of battery poor. In this paper, polyethylene glycol (PEG400) and potassium iodide were added into zinc-ion aqueous electrolyte. PEG400 could complex with iodine to reduce the dissolution of iodine, therefore alleviating the formation of soluble triiodide (I₃^–) from iodine and iodide ions. Furthermore, this electrolyte was used in the battery with double carbon cloths as the current collectors, double separators and zinc …

Constructing Carbon-Encapsulated Nifev-Based Electrocatalysts By Alkoxide-Based Self-Template Method For Oxygen Evolution Reaction, En-Hui Ma, Xu-Po Liu, Tao Shen, De-Li Wang

Journal of Electrochemistry

The development of green and sustainable water-splitting hydrogen production technology is beneficial to reducing the over-reliance on fossil fuels and realizing the strategic goal of "carbon neutral". As one of the half reactions for water splitting, oxygen evolution reaction has suffered the problems of sluggish four-electron transfer process and relatively slow reaction kinetics. Therefore, exploring efficient and stable catalysts for oxygen evolution reaction is of critical importance for water-splitting technology. Metal alkoxides are a series of compounds formed by the coordination function of metal ions with alcohol molecules. Metal alkoxides possess the double advantages of organic materials and inorganic materials, …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

A Computational Approach For Mapping Electrochemical Activity Of Multi-Principal Element Alloys, Jodie A. Yuwono, Xinyu Li, Tyler D. Dolezal, Adib J. Samin, Javen Qinfeng Shi, Zhipeng Li, Nick Birbilis

Faculty Publications

Multi principal element alloys (MPEAs) comprise an atypical class of metal alloys. MPEAs have been demonstrated to possess several exceptional properties, including, as most relevant to the present study a high corrosion resistance. In the context of MPEA design, the vast number of potential alloying elements and the staggering number of elemental combinations favours a computational alloy design approach. In order to computationally assess the prospective corrosion performance of MPEA, an approach was developed in this study. A density functional theory (DFT) – based Monte Carlo method was used for the development of MPEA ‘structure’; with the AlCrTiV alloy used …

Chain Conformation And Exciton Delocalization In A Push-Pull Conjugated Polymer, Yulong Zheng, Rahul Venkatesh, Connor P. Callaway, Campbell Viersen, Kehinde H. Fagbohungbe, Aaron L. Liu, Chad Risko, Elsa Reichmanis, Carlos Silva-AcuñA

UK CARES Faculty Publications

Linear and nonlinear optical line shapes reveal details of excitonic structure in polymer semiconductors. We implement absorption, photoluminescence, and transient absorption spectroscopies in DPP-DTT, an electron push−pull copolymer, to explore the relationship between their spectral line shapes and chain conformation, deduced from resonance Raman spectroscopy and from ab initio calculations. The viscosity of precursor polymer solutions before film casting displays a transition that suggests gel formation above a critical concentration. Upon crossing this viscosity deflection concentration, the line shape analysis of the absorption spectra within a photophysical aggregate model reveals a gradual increase in interchain excitonic coupling. We also observe …

Flexible And Sewable Electrode Based On Ni-Co@Pani-Salphen Composite-Coated On Textiles For Wearable Supercapacitor, Touba Rezaee Adriyani, Ali A. Ensafi, B. Rezaei

Chemistry & Biochemistry Faculty Publications and Presentations

Flexible electrodes with high deformability and energy density are critical for electronic textiles. The key factor for achieving high-performance supercapacitors with superior power and energy density is the evaluation of materials that exhibit exceptional capacitive performance. Herein, we have prepared Ni-Co nanoparticles at the surface of polyaniline-salphen (Ni-Co@PS). Then, followed by casting Ni-Co@PS on a conductive carbon cloth (CC) as a substrate through a facile in-situ polymerization strategy. The morphologies of Ni-Co@PS composite were characterized by different methods such as FE-SEM, XPS, XRD, BET, and electrochemical methods. This nanocomposite showed high tolerability and a large surface area with excellent behavior …

Hydroxyapatite-Based Coatings On Silicon Wafers And Printed Zirconia, Antoine Chauvin

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Dental surgery needs a naturally attract implant design that can ensure both osseointegration and soft tissue integration. Hydroxyapatite (HAp), the main mineral constituent of dentine and tooth enamel, is commonly used as a coating component, notably for overlaying titanium– or ceramics–based implants. This thesis aims to investigate the behavior of a HAp-based coating, specifically designed to be compatible with a porous substrate. Coating layers are made by sol–gel dip coating by immersion of porous substrates made by additive manufacturing into solutions of HAp, having been mixed with polyethyleneimine (PEI), to improve the adhesion of HAp on the substrate. First, the …

Research Progress And Performance Improvement Strategies Of Hard Carbon Anode Materials For Sodium-Ion Batteries, Xiu-Ping Yin, Yu-Feng Zhao, Jiu-Jun Zhang

Journal of Electrochemistry

This paper systematically summarizes the research progress of hard carbon anode materials in sodium ion batteries(SIBs) and the development of the corresponding sodium storage mechanism in recent years, and reviews the performance improvement strategies of hard carbon materials from the aspects of structural design and electrolyte regulation. The effects of the selection of precursors, carbonization temperature, pretreatment, pore formers, heteroatom doping, material compounding, electrolyte regulation and pre-sodiumization on the sodium storage performance of hard carbon anode materials are briefly described. This paper provides new insights into the design, synthesis and electrolyte
matching of high-performance and low-cost hard carbon materials, and …

Charge-Dependence Of Dissolution/Deposition Energy Barrier On Cu(111) Electrode Surface By Multiscale Simulations, Hang Qiao, Yong Zhu, Sheng Sun, Tong-Yi Zhang

Journal of Electrochemistry

Behaviors of electrified interface under different applied potentials/charges play the central role in electroplating process and electrochemical corrosion. The mechanism, however, is unclear yet for a surface atom dissolving/depositing from/on an electrode surface under an applied potential. The energy barrier along the reaction path is the key variable. The present work conductes hybrid first-principle/hybrid calculations to study the direct and indirect dissolution/deposition of a Cu atom on perfect/stepped Cu(111) planar electrodes in an electrolyte under different excess charges. Energy profiles present a linear relationship between the energies of the initial/final state and the activation state of different reaction paths under …

Surface Modifications Of Lini0.96Co0.02Mn0.02O2 With Tungsten Oxide And Phosphotungstic Acid, Gang Zhao, Zheng-Liang Gong, Yi-Xiao Li, Yong Yang

Journal of Electrochemistry

With the rapid development of electric vehicles, enormous demands are made for higher energy density, better cycling performance and lower cost of lithium-ion batteries (LIBs). As an important high capacity cathode material for LIBs, the high nickel layered oxide material LiNi_0.8Co_0.1Mn_0.1O₂(NCM811) can reach an energy density of 760 Wh·kg^-1. The ultra-high nickel ternary positive electrode material (LiNi_1-x-yCo_xMn_yO₂, x ≥ 0.90) has a specific capacity of more than 210 mAh·g^-1, and can realize higher energy density. Besides, an ultra-high nickel material …

Preparation And Electrocatalytic Performance Of Feni-Cop/Nc Bifunctional Catalyst, Si-Miao Liu, Jing-Jiao Zhou, Shi-Jun Ji, Zhong-Sheng Wen

Journal of Electrochemistry

Rechargeable zinc-air batteries have gradually attracted much attention worldwide due to their high capacity, high energy density and low price. Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) correspond to the charging and discharging processes in rechargeable zinc-air battery, respectively. At present, commercial Pt/C and IrO₂ catalysts hinder the large-scale application of zinc-air batteries due to low reserves, high prices and poor stability. Therefore, exploring high performance, low cost and high stability with dual functional catalysts is important for the development of rechargeable zinc-Air batteries. The metal-organic frameworks (MOFs) have high specific surface area, structural stability, good catalytic …

Corrosion Related To The Nuclear Waste Containers, Ali Ebrahimzadeh Pilehrood

Corrosion Research

The disposal of nuclear waste is a demanding topic, and the existing methods, whether it is temporary storage in spent fuel pools or storage in geological repositories, both face the risk of corrosion-related problems. Any failure in these storage methods can potentially lead to the release of radioactive materials into the environment. To avert such catastrophic scenarios, people in the nuclear industry consistently monitor and maintain these storage facilities endlessly and attempt to improve the plans designed to store nuclear waste. Here, I will examine the nuclear waste management organization (NWMO) plan in Canada. Choosing an appropriate location for the …