Physical Chemistry Commons^™

Designing A Reactor Chamber For Hot Electron Chemistry On Bimetallic Plasmonic Nanoparticles, Bryn Merrill, Bingjie Zhang, Jerry Larue

SURF Posters and Papers

Catalysis provides pathways for efficient and selective chemical reactions by lowering the energy barriers for desired products. Gold nanoparticles (AuNPs) show excellent promise as plasmonic catalysts. Plasmonic materials have localized surface plasmon resonances, oscillations of the electron bath at the surface of a nanoparticle, that generate energetically intense electric fields which rapidly decay into energetically excited electrons. The excited electrons have the potential to destabilize atoms strongly bound to the catalysts through occupation of antibonding orbitals. Tuning the antibonding orbitals to make them accessible for occupancy by electrons is achieved by coating the AuNP in a thin layer of another …

Probing The Surface Acidity Of Supported Aluminum Bromide Catalysts, Md Ashraful Abedin, Swarom Kanitkar, Nitin Kumar, Zi Wang, Kunlun Ding, Graham Hutchings, James J. Spivey

Faculty Publications

Solid acid catalysis is an important class of reactions. The principal advantages of solid acid catalysts as compared to their corresponding fluid acids include minimal waste and ease of product separation. One type of these catalysts is based on aluminum bromide (Al2Br6), which is a stronger Lewis acid than Al2Cl6. In this report, Al(2)Br(6)is grafted on commercial mesoporous silica (CMS), SBA-15 and silica gel to create a solid catalyst similar to the silica-supported Al(2)Cl(6)superacid. These supported Al(2)Br(6)catalysts were characterized by NH3-Temperature Programmed Desorption (TPD), pyridine Diffuse Reflectance for Infrared Fourier Transform Spectroscopy (DRIFTS) and Magic Angle Spinning Nuclear Magnetic Resonance …

Computational Elucidation Of The "Coloring Problem" In Rhenium Aluminum Silicon Compounds, Alec George Neeson

Graduate Theses/Dissertations

Re₁Si₁Al₁ and its related compounds are potential thermoelectric materials. Previously, it was reported to adopt a MoSi₂-type structure with Si and Al atoms statistically sharing the same crystallographic sites. This recent study indicates otherwise – Si and Al are segregated and occupy different sites when mixed with a 1:1:1 stoichiometry. To confirm and rationalize the segregation between Si and Al, this research studied this compound with first-principle calculations. Several model structures have been constructed for Re₁Si₁Al₁ including a number of different super-cell models. Energy analysis confirmed that the …

In Silico Investigation For The Conversion Of Methyl Oleate To Gasoline, Arkanil Roy

Graduate Theses/Dissertations

Petroleum products are found in all walks of life. From the plastic casing on a cell phone to the gasoline that runs most vehicles, a lot is derived from petroleum. Ubiquitous use of petroleum has adversely affected the environment. Toxic substances such as SOx and NOx are released into the atmosphere during the processing and usage of petroleum products, which contributes to global warming. Inevitable oil spills cause devastating effects to marine ecosystems. The rate of regeneration of petroleum is much slower than the rate of usage that would lead to it being exhausted in the recent future. Hence, a …

How Oxygen-Binding Affects Structural Evolution Of Even-Sized Gold Anion Clusters (Size Range 20 To 34), David Brunken-Deibert

Department of Chemistry: Dissertations, Theses, and Student Research

We report a joint anion photoelectron spectroscopy (PES) and theoretical study to investigate the effect of O₂-binding on the mid-sized even-numbered gold clusters, Au_n− (n = 20−34), a special size region of bare gold clusters that entail rich forms of structural evolution and transformation. Specifically, within this size range, bare Au₂₀₋ is a highly-symmetric pyramidal cluster, bare Au_21-25− are flat-planar or hollow-tubular clusters, bare Au₂₆₋ is the smallest core-shell gold cluster, while bare Au₃₄₋ is a magic-number/fluxional core-shell cluster with the high-symmetry tetrahedral Au₄ core. In light of the strong …

Chemistry And Biochemistry Authored Faculty Publications: Snapshot Of The Ranking Of Journals In Which They Published Based On Data From Journal Citation Reports (Jcr), Lutishoor Salisbury, Yang Tian, Jeremy Smith

University Libraries Faculty Publications and Presentations

This report presents a snapshot of the research output of the Chemistry and Biochemistry Department at the University of Arkansas for the period 2015-2019. The contents of the report were generated using Web of Science Core Collection databases and the Journal Citation Report only. It highlights the journals in which the researchers published and the ranking of those journals.

Visualization Without Vision – How Blind And Visually Impaired Students And Researchers Engage With Molecular Structures, Croix J. Laconsay, Henry B. Wedler, Dean J. Tantillo

Journal of Science Education for Students with Disabilities

This article examines the tools and techniques currently available that enable blind and visually impaired (BVI) individuals to visualize three-dimensional objects used in learning chemistry concepts. How BVI individuals engage with and visualize molecular structure is discussed and recent tactile (or haptic) and auditory methods for visualization of various chemistry concepts are summarized. Remaining challenges for chemistry education researchers are described with the aim of highlighting the potential value of educational research in further enabling BVI students to pursue careers in science, technology, engineering, and mathematics (STEM) fields.

Solvation Structures And Dynamics Of Small Molecules: Experimental And Computational Studies Using Carbonyl Vibrational Modes As Probe, Xiaoliu Zhang

LSU Doctoral Dissertations

Solutions are ubiquitous in both the global environment and the human body, and play a significant role in scientific research and industrial production. The structures and dynamics of solutions have been studied for centuries. However, conventional experimental methods, whose intrinsic measuring time is on the order of nanoseconds to microseconds, could not detect the fast dynamics taking place in the solution on the timescale of femto- and pico-second. In this dissertation, the ultrafast two-dimensional infrared (2DIR) spectroscopy was applied to characterize the structure and dynamics in three different types of solutions on the sub-picosecond timescale. Linear Fourier transform infrared spectroscopy …

Synthesis Of Cds/Zns Core/Shell Semiconductor Nanoparticles, Austin Skyler Antle

Masters Theses & Specialist Projects

Core/shell semiconductor nanoparticles are of great interest as photocatalysts due to their large surface area per volume and tunable band gaps. The synthesis of core/shell semiconductor nanoparticles has traditionally involved the use of binding ligands to ensure the particles do not aggregate. These binding ligands lower the surface area of the nanoparticles though, reducing their overall efficiency. Ionic liquids have been found to be capable of acting as both solvents and stabilizing agents for synthesis of catalysts with highly active surfaces. Our experiments focus on the synthesis of CdS/ZnS core/shell nanoparticles with the ionic liquid 1-butyl-3-methylimidazolium methyl sulfate, [BMIM][MeSO4], acting …

Ensemble And Single Particle Studies Of Cation Exchange In Cuins2/Zns Qds And Their Application In Super-Resolution Imaging, Anh Tue Nguyen

Graduate Theses and Dissertations

Colloidal quantum dots (QDs) have great potential in many applications such as bioimaging, light emitting diodes, solar cells and lasers. However, a great number of studies have been focused on Cd based (II-VI) and Pb (IV-VI) based materials which are not suitable for mass production. Therefore, alternative types of QD containing less toxic materials have been introduced, including CuInS2 QDs. This I-III-VI semiconductor nanocrystals also attract lots of attention due to their large Stock shift, long fluorescence lifetime and high defect tolerance, making them attractive emitters for applications in bioimaging, photovoltaics and light emitting diodes.

In the first project, we …

Synthesis And In Vitro Studies Of Polycaprolactone-Coated Superparamagnetic Iron Oxide Nanoparticles For Magnetic Hyperthermia Therapy, Nasab Ziba Hedayat

Student Works (2020-2029)

Research has garnered a great interest in utilization of superparamagnetic iron oxide nanoparticles (SPIONs) as magnetic nano-heating agents in hyperthermia cancer therapy by profiting from high apoptosis vulnerability of cancer cells at elevated temperatures. However, low oxidation resistance and high agglomeration tendency negatively affect magnetic characteristics of nanoparticles and subsequently their clinical efficiency. Particle surface modifications are potential approaches to endow SPIONs a range of desirable properties including high colloidal dispersity, low aggregation tendency, cytocompatibility, and high oxidation resistance. Currently, polymer coating has led to decrease magnetic hyperthermia efficiency through formation of intermediate layer between nanoheating agents and targeted cells. …

Syntheses, Characterisations And Electrochemical Studies Of Nickel(Ii) And Cobalt(Ii)-Ligand Assisted Cooperative Complexes, Subramaniam Jeevithra Dewi

Student Works (2020-2029)

A newly designed tetradentate ligand L1 (L1 = 3,6-bis(pyrazol-1-yl)-pyridazine) which offers multinucleation sites on its moiety structure has been prepared. The reaction of L1 with different molar ratio of nickel and cobalt salts lead to the formation of di- and tetranuclear complexes [NiII 2(L1)2(CH3CN)4](PF6)4 (1), [NiII 4(L1)4(μ-OH)4](ClO4)4 (2) and [CoII/III(L1)4(μ-CH3O)2(μ-O)2](PF6)3(NO3) (3), which served as the attempt to design of catalysts based on cheap and earth-abundant metals for carbon dioxide reduction. The presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the base controls the nuclearity of the complex formation. In the absence of DBU, complex 1 was formed in dinuclear fashion whereas complex 2 …

An Experimental Investigation Of Liquid Hydrocarbons In A Simulated Titan Environment, Kendra Farnsworth

Graduate Theses and Dissertations

Saturn’s moon, Titan, has surface conditions (89–94 K, 1.5-bar atmosphere) that permit lakes of methane, ethane, and dissolved atmospheric nitrogen. The effects of atmospheric nitrogen on methane-ethane liquid properties is poorly understood, leading to uncertainty in Titan modeling. I address this question by experimentally investigating the physical properties of methane-ethane liquids under a 1.5-bar nitrogen atmosphere in a simulated Titan environmental chamber.

Chapter 1 addresses nitrogen dissolution kinetics in Titan’s liquid hydrocarbons. I found an exponential increase in nitrogen quantity and diffusion coefficients with increasing methane mol%. I find that Titan’s liquids are likely not saturated in nitrogen, with dissolution …

Poly(Ethylene Oxide) Based Polymer Electrolytes For All-Solid-State Li-S Batteries, Xue Li, Zheng-Liang Gong

Journal of Electrochemistry

In recent years, research on lithium-sulfur (Li-S) batteries has received much attention because the sulfur positive electrode and the lithium metal negative electrode produce a high theoretical specific capacity (lithium metal ~ 3800 mAh·g^-1, sulfur ~ 1675 mAh·g^-1). In addition, sulfur is considered to be the most promising cathode material for secondary lithium batteries, due to its advantages of low price and environmental friendly. However, the practical application of conventional liquid Li-S batteries is still obstructed by several critical issues, such as lithium ploysulfides shuttle effect, long-term stability of lithium metal anode with organic liquid electrolytes, …

Synthesis And Raman Study Of Hollow Core-Shell Ni1.2Co0.8P@N-C As An Anode Material For Sodium-Ion Batteries, Jia-Hui Chen, Xiao-Bin Zhong, Chao He, Xiao-Xiao Wang, Qing-Chi Xu, Jian-Feng Li

Journal of Electrochemistry

With the increasing demand for large-scale energy storage, great progress has been made in discovering new advanced energy storage materials. Sodium-ion batteries (SIBs) have attracted much attention in recent years due to their use of abundant sodium resources and their comparable electrochemical capacity to lithium-ion batteries (LIBs). In this paper, we developed novel hollow core-shell Ni-Co bimetallic phosphide nanocubes with N-doped carbon coatings (Ni_1.2Co_0.8P@N-C) as the anode material for SIBs. The material was synthesized through a low-temperature phosphorization method using resorcinol formaldehyde (RF) resin coating with a Ni-Co Prussian blue analogue (PBA) as a template and …

Preparations Of Nano-MnoX/Ti Electrocatalytic Membrane Electrode For Catalytic Oxidation Of Cyclohexane Using Intermittent Electrodeposition, Xue Zhou, Hong Wang, Zhen Yin, Yu-Jun Zhang, Jian-Xin Li

Journal of Electrochemistry

Cyclohexanone and cyclohexanol (KA oil) obtained from highly selective oxidation of cyclohexane (CHA) show important industrial value and application prospects. In this work, the intermittent electrodeposition was developed to prepare nano-MnO_x catalyst loading porous tubular titanium membrane electrode (MnO_x/Ti), which was employed to constitute an electro-catalytic membrane reactor (ECMR) for the oxidation of cyclohexane to produce cyclohexanol and cyclohexanone. The surface morphology, crystal structure and electrochemical property of the catalysts were characterized by FESEM, XRD and electrochemical workstation, respectively. The results show that the catalyst prepared by the intermittent electrodeposition displayed nano-flower-like γ-MnO₂. Compared with …

Recent Advancement In Pseudo-Random Binary Sequence Signals-Based Fast Reconstruction Of Impedance Spectrum And Its Applications In Electrochemical Energy Sources, Wei-Heng Li, Qiu-An Huang, Wei-Ming Yang, Chang-Ping Yang, Jiu-Jun Zhang

Journal of Electrochemistry

With the extensive application of impedance spectroscopy, the time-consuming issue of its traditional testing methods has become more and more serious, which limits its application range. In the study of accelerating impedance measurement or reconstruction, the synthesis of wideband excitation signals and the design of high efficiency estimation algorithms have been identified as important ways. In view of the purpose of rapid impedance reconstruction, Pseudo-Random Binary Sequence (PRBS) has the advantages of flat power spectrum and easy generation, and has a good application prospect. This paper reviews three core issues in rapid reconstruction of impedance spectrum: PRBS signal types, different …

Preparation Of Α-Hydroxylated Acetal From 2-Butanone By Indirect Electrooxidation, Hai-Qing Huang, Ye Miao, Xin-Sheng Zhang

Journal of Electrochemistry

Acetoin (3-hydroxy-2-butanone) is an important food spice. As a platform compound, it is widely used in medicine, tobacco, cosmetics, chemical material and other industries. In this paper, α-hydroxylated acetal, an intermediate of acetoin, was prepared from 2-butanone by indirect electrooxidation in the plate and frame electrolytic cell, in which graphite plates were used as both an anode and a cathode, while KOH as an electrolyte and KI as a catalyst. Acetoin could be prepared by hydrolysis in acidic aqueous solution from acetoin intermediate. The effects of current density, electrolyte flow rate between the plates, 2-butanone concentration and electrolysis temperature …

The Interaction Of Ternary Components Of Ionic Liquid Gel Polymer Electrolytes For Lithium Metal Batteries, Xiao-Na Pan, Li-Lai Liu, Zhi-Pu Wang, Dan Wang, Yun Li, Pei-Xia Yang, Jin-Qiu Zhang, Mao-Zhong An

Journal of Electrochemistry

Ionically conductive gel polymer electrolyte is an excellent candidate due to its inflammable, nonvolatile and high thermal stability as compared to commercial liquid electrolytes which are usually flammable, volatile, and containing toxic organic solution as solvent, The synthesis and application of ionic gel polymer electrolytes in lithium ion/metal batteries have been previously reported. However, the interaction effects of N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13TFSI) ionic liquid (as plasticizer) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) on PVDF-HFP polymer remain unclear. In this work, the molecular structure of ionic liquid gel polymer electrolyte (ILGPE) composed of PP13TFSI, LiTFSI and PVDF-HFP was studied by Raman spectroscopy and Fourier-transform …

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 …

Ordered Mesoporous Carbon/Graphene/Nickel Foam For Flexible Dopamine Detection With Ultrahigh Sensitivity And Selectivity, Lai-Yu Wang, Xin Xi, Dong-Qing Wu, Xiong-Yu Liu, Wei Ji, Rui-Li Liu

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

Electrochemical Response Of A Single Wire-Electrode Ac Probe In 3.5wt.% Nacl, Zhen-Wen Zou, Da-Jiang Zheng, Zi-Ming Wang, Guang-Ling Song

Journal of Electrochemistry

In this paper, a recently developed single wire-electrode AC probe technology which does not need a reference or counter electrode was employed to investigate the electrochemical corrosion and sacrificial anode protection behaviors of steel and zinc in 3.5wt.% NaCl. With this simple, fast, reliable and stable probe, the instantaneous corrosion rate and accumulated corrosion loss of carbon steel in 3.5wt.% NaCl were measured, and the results revealed that both were greater than those of zinc. Furthermore, the observed different corrosion behaviors between carbon steel and zinc during the immersion could be caused by their different surface films. With the galvanic …

Stability Studies For A Membrane Electrode Assembly Type Co2 Electro-Reduction Electrolytic Cell, Qing Mao, Bing-Yu Li, Wei-Yun Jing, Jian Zhao, Song Liu, Yan-Qiang Huang, Zhao-Long Du

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

A Simple And Sensitive Aptamer-Based Electrochmical Sensor For Determination Of Aflatoxin B1, Bing Liu, Yao-Shuai Zhao, Yue Qin, Yi Wang, Yan-Jie Zhu, Shuo Wang

Journal of Electrochemistry

Aflatoxin B1 has attracted much attention because of its high toxicity and carcinogenicity, which has become a great concern in food safety. Based on the principle of specific binding between Aflatoxin B1 and its aptamer, an aptamer-based electrochemical sensor had been designed and developed for the determination of minor Aflatoxin B1 contained in grain. The mesoporous carbons were first modified on the surface of the working electrode, and then the gold nanoparticles were on-site electrodeposited at a constant potential. Each modified electrode was characteritised by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). As a result, the surface area …

Degradation Mechanism Of Lini0.83Co0.12Mn0.05O2 Cycled At 45 ℃, Hong-Yun Ma, Xiao-Hui Yao, Meng-Yao Miao, Yang Yi, Shao-Zhong Wu, Jiang Zhou

Journal of Electrochemistry

Nickel-rich layered material has been considered as the most promising one for lithium ion batteries due to its high specific capacity. To further improve the lifetime performance, it is significant to investigate the degradation mechanisms deeply. In this study, the degradation mechanism of NCM811 (LiNi_0.83Co_0.12Mn_0.05O₂) being cycled at 45^oC was systematically researched. Electrochemical impedance spectrum (EIS) results showed that the SEI resistance (R_SEI) and charge transfer resistance (R_ct) went up to 83.41% and 211.34% before and after the NCM811 material being cycled at 45^oC, …

Benzosiloles With Crystallization-Induced Emission Enhancement Of Electrochemiluminescence: Synthesis, Electrochemistry, And Crystallography, Liuqing Yang, Donghyun Koo, Jackie Wu, Jonathan M. Wong, Tyler Day, Ruizhong Zhang, Harshana Kolongoda, Kehan Liu, Jian Wang, Zhifeng Ding, Brian Pagenkopf

Chemistry Publications

Crystallization-induced emission enhancement (CIEE) was demonstrated for the first time for electrochemilunimescence (ECL) with two new benzosiloles. Compared with their solution, the films of the two benzosiloles gave CIEE of 24 times and 16 times. The mechanism of the CIEE-ECL was examined by spooling ECL spectroscopy, X-ray crystal structure analysis, photoluminescence, and DFT calculation. This CIEE-ECL system is a complement to the well-established aggregation-induced emission enhancement (AIEE) systems. Unique intermolecular interactions are noted in the crystalline chromophore. The first heterogeneous ECL system is established for organic compounds with highly hydrophobic properties.

Study Of Pharmaceutical Tablets Using Raman Mapping, Kyle Joseph Pauly

Honors Theses

Covalent bonds are the strongest type of bonds holding molecules together. Based on the pattern of bonding of the molecule, the atoms associated with the bond will vibrate at a specific frequency. Utilizing vibrational spectroscopy, such as Raman spectroscopy, these unique vibrational frequencies can be used to detect the presence of analytes over a selected area. Furthermore, the intensities of the vibrational modes can be tracked to comparatively quantify the concentration of analytes at various locations. This is a method of great importance due to its ability to compare pharmaceutical tablets synthesized with different techniques. Here, the presence and concentration …

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized heating, …

Behavior Of Iron Species And Free Radicals In Ambient Pm2.5 And Pm Surrogates, Cholena Russo Ren

LSU Doctoral Dissertations

Air pollution, consisting of ambient particulate matter (PM), has been a rising health concern to the public. PM contains free radicals and have been known to damage human cells; however, their free radical chemistry is not well understood. This study utilized various vacuum and/or heat treatments to study free radical behavior in PM_2.5 (particulate matter with an aerodynamic diameter of 2.5 mm or less) and PM surrogates and simulated sunlight effects on PM_2.5. To mimic PM, iron-silica catalysts (i.e. PM surrogates) were synthesized and real-world ambient PM_2.5 was selected. The free radicals in PM_{2.5 …}

Raman Spectroscopy Study Of Delta-9-Tetrahydrocannabinol And Cannabidiol And Their Hydrogen-Bonding Activities, Kalee Sigworth

Honors Theses

Cannabis and products containing its cannabinoids have grown rapidly in acceptance and use in recent years with legalization of cannabis in many countries and US states. Cannabidiol and Delta-9-Tetrahydrocannabinol are two primary cannabinoids in Cannabis that have been shown to produce analgesic effects along with many other positive side effects for the user. These two cannabinoids interact with receptors in the Central and Peripheral Nervous Systems. No spectroscopic study to our knowledge has been performed to analyze the hydrogen bonding effects of interactions between these two cannabinoids and solvents. Here, we employ theoretical Raman spectra through computational methods to study …