Chemistry Commons^™

Research Progress Of Mn-Based Lithium-Rich Cathode Materials For Li-Ion Batteries, Luo-Zeng Zhou, Qun-Jie Xu, Wei-Ping Tang, Xue Jin, Xiao-Lei Yuan

Journal of Electrochemistry

With rapid development of new energy industry like electric vehicles and energy storage station, these fields highly demand the next generation of high performance Li-ion battery systems with stronger energy density, higher power density, and longer cycling life. Lithium-rich Mn-based cathode materials, xLi₂MnO₃·(1-x)LiMO₂(M=Mn, Co, Ni...), have become the hot topic and drawn attentions of scholars worldwide because of their high reversible capacity exceeding 240 mAh·g^-1, excellent electrochemical properties, and low cost, which makes them most promising cathode material candidates for next Li-ion battery system. The cathode material Li[Li_0.2Mn_0.54Ni …

Preparation And Properties Of Binary Oxides CoXCr1-XO3/2 Electrocatalysts For Oxygen Evolution Reaction, Tai-Lai Yang, Wen-Yan Dong, Hui-Min Yang, Li Zhang, Zhen-Hai Liang

Journal of Electrochemistry

Binary metal mixed oxides of Co and Cr with nominal compositional formulas, Co_xCr_1-xO_3/2 (x=0, 0.2, 0.4, 0.6, 0.8 and 1.0), were obtained by thermal decomposition method. The morphologies, crystal forms and valence states of the catalyst powders were analyzed by SEM, XRD and XPS, respectively. And the electrochemical properties, overpotentials and stabilities of Co_xCr_1-xO_3/2 electrodes for oxygen evolution reaction (OER) in an alkaline solution were evaluated by linear sweep voltammetry (LSV), staircase voltammetry and chronoamperometry, respectively. The results indicated that the mixtures of Co₃O₄ and eskolaite-Cr_{2 …}

Synthesis And Electrochemical Properties Of Cnts/V2O5 Hollow Microspheres, Liang Hao, Lai-Fa Shen, Jie Wang, Jia-Jia Zhu, Xiao-Chen Zhao, Xiao-Gang Zhang

Journal of Electrochemistry

The carbon nanotubes/vanadium oxides (CNTs/V₂O₅) hollow microspheres (VOC) were prepared via solvothermal process. The effects of the ratio for CNTs to V₂O₅ on the morphologies, structures and electrochemical performances were systemically investigated. The results indicate that CNTs dramatically enhanced the rate performances of VOC composite electrodes. When the ratio of CNTs is 7.1%, the VOC composite electrode exhibited the best electrochemical performance, which delivered a specific capacitance of 346 F·g^-1 at 0.5 A·g^-1 and maintained 75% at 8 A·g^-1 in 5 mol L^-1 LiNO₃. A hybrid capacitor …

A Platinum-Hydrogen Reference Micro-Electrode For All Vanadium Redox Flow Battery, Zhi-Bin Lin, Yan-Qing Dong, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

A platinum-hydrogen reference micro-electrode was made with electroplating Pd on the surface of Pt wire and then coating anion membrane material. This reference electrode was built-in the porous electrode of the all vanadium redox flow batteries (VRFB), and monitored the charging /discharging and self-discharging of the VRFB. The results indicated that the capacity fading of VRFB occurred due to the graduate reduction of V(IV) active species in the electrolyte and the accumulation of V(V) in the positive electrode, leading to nonequilibrium of active species between the positive and negative electrodes.

Electrochemical Conversion Reactions And Their Applications For Rechargeable Batteries, Ting Li, Han-Xi Yang

Journal of Electrochemistry

Electrochemical conversion reactions have received considerable interest as a new redox mechanism for constructing high capacity electrodes of rechargeable batteries. Without strict restrictions on the crystalline structure of the host lattice and the size of the associated ions, conversion reactions can take place in a variety of different metal compounds with different metal cations and deliver much higher reversible capacities through full utilization of all the oxidation states of the transition-metal compounds, opening up a new avenue for developing high capacity materials of rechargeable batteries. This paper briefly reviews the state of the art and challenges of conversion electrodes and …

Electrochemical Performance And Reaction Mechanism Of Li3Fe2(Po4)3/C Cathode Material, Yong Xie, Gui-Ming Zhong, Zheng-Liang Gong, Yong Yang

Journal of Electrochemistry

The cathode material of carbon coated Li₃Fe₂(PO₄)₃ (Li₃Fe₂(PO₄)₃/C) is successfully prepared by sol-gel method and ball-milling carbon coating technique. The cathode material is characterized by XRD, SEM, TEM, and in-situ XAFS techniques. XRD results indicate that the as prepared Li₃Fe₂(PO₄)₃ is of high purity and single phase, and has monoclinic structure with space group of P21/n. Electrochemical measurements show that the carbon-coated material is able to deliver a high initial discharge specific capacity of 128.6 mAh·g^-1 in …

Electrochemical Performance Of Coal2O4-Coated Lini1/3Co1/3Mn1/3O2, Ji-Jun Cai, Wang-Jun Cui, Bing Li, Yang-Yang Yu, Jin-Bao Zhao

Journal of Electrochemistry

A method to improve the electrochemical performance of LiNi_1/3Co_1/3Mn_1/3O₂ for high voltage lithium-ion battery by CoAl₂O₄ coating was present in this work. The effects of CoAl₂O₄ coatings on the structure and electrochemical properties of LiNi1/3Co1/3Mn1/3O2 were investigated in detail. The results show that CoAl₂O₄ forms a thin layer of 8 nm on the surface of LiNi_1/3Co_1/3Mn_1/3O₂ without destroying the structure of the core material. The CoAl₂O₄-coated LiNi_1/3Co_1/3Mn_1/3O …

Porous Co3O4 Hollow Nanospheres Cathode Catalyst For High-Capacity And Long-Cycle Li-Air Batteries, Tong Liu, Na Li, Qing-Chao Liu, Xin-Bo Zhang

Journal of Electrochemistry

In this paper, a high specific surface area of porous Co3O4 hollow nanospheres was successfully synthesized via hydrothermal carbonization at 140 °C, followed by calcination using cobalt nitrate hexahydrate (Co(NO3)2·6H2O), hexamethylenetetramine (HMT), sucrose, and sodium citrate (Na3C6H5O7). The porous Co3O4 hollow nanospheres consisted of nanoparticles with high specific surface area of mesoporous structure, and could provide active reaction sites for OER and ORR. When used as lithium-air battery cathode catalyst, the Co3O4/Super P (SP) electrode exhibited excellent cycle performance, resulting in high capacity and long life of lithium-air batteries.

Response Characteristics Of Solution-Gated Graphene Field Effect Transistors To Buffer Solution Ph And Concentration, Xiao-Wei Du, Ji Cheng, Hui Guo, Qing-Hui Jin, Jian-Long Zhao

Journal of Electrochemistry

High-sensitivity and low-noise solution-gated graphene field effect transistors (SGFETs) were fabricated using chemical vapor deposition (CVD) graphene as a channel material, and their response characteristics to concentration and pH of phosphate buffered saline (PBS) were measured. The minimum conductance point shifted to left with increasing concentration, and the offset showed a linear relationship with the natural logarithm of concentration. While, the minimum conductance point shifted to right with increasing pH, and the offset showed a linear relationship with pH. The research on these response characteristics may give proper guidance to SGFETs’s application.

Electrodeposition Of Al-Mg Alloys From Acidic Alcl3-Emic-Mgcl2 Room Temperature Ionic Liquids, Rostomali M., P. Abbott Andrew, S. Ryder Karl

Journal of Electrochemistry

Electrodeposition of aluminium-magnesium alloys have been carried out onto platinum and copper cathodes from Lewis acidic aluminium(III) chloride-1-ethyl-3-methylimidazolium chloride ionic liquid containing magnesium(II) chloride by constant current and constant potential methods at room temperature. Magnesium content in the deposited alloy increases with increasing MgCl₂ concentration in the ionic liquid and with increasing cathodic current density. The influences of various experimental conditions on electrodeposition and the morphology of the electrodeposited layers have been investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDAX). On increasing the deposition current densities the dense, bright, adherent …

Syntheses And Electrochemical Performances Of Li4Ti5O12 Anode Materials For Lithium Ion Battery, Yong-Long Zhang, Xue-Bu Hu, Yao-Qiong Wang, Dong-Hai Huang

Journal of Electrochemistry

Series of spinel lithium titanate (Li₄Ti₅O₁₂) materials were synthesized by one-step solid-state reaction using lithium acetate and TiO₂ as raw materials under different temperatures (750/800/850 °C) and atmospheres (N₂/air). The as-prepared Li₄Ti₅O₁₂ materials were investigated by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, cyclic voltammotry and charge-discharge test to analyze their crystal structures, microstructures and electrochemical performances. The results show that the Li₄Ti₅O₁₂（L-800N）material obtained at 800 °C under nitrogen atmosphere exhibited better electrochemical performance and smaller particle size. The initial …

Investigations Of Synthetic Fuels: S8 And Sasol Ipk To Determine The Possibility Of Alternate Fuels In The Aerospace Industry, Scott M. Dyke

GS4 Student Scholars Symposium

Investigations of Synthetic Fuels: S8 and Sasol IPK to Determine the Possibility of Operation as Alternate Fuels in the Aerospace Industry

Name: Scott Dyke

Co-Authors: Martin Muinos, Julia Heimberger, Dr. Valentin Soloiu,

An ever-growing society that becomes more and more dependent on a finite energy source will eventually exceed its supply. Fossil fuel quantities are continuously decreasing and new solutions are needed. According to the United States Department of Transportation, over 10 billion gallons of airline fuels have been consumed in each of the past 15 years with some years over 13 billion gallons. In the meantime, fuel costs have …

Phenanthroline Derivatives As Potential Sensors, David L. Sellers

Research and Creative Activities Poster Day

Derivatives of 1,10-phenanthroline have great potential as functional sensor molecules for detection of nerve agents by colorimetric assays. In this study we prepared aminoalcohol deriviatives of 1,10-phenanthroline. Deriviatives were obtained in moderate to high yields. Metal complexes of 1,10-phenanthroline were also prepared. The metal complexes allow for greater stability of the sensors and greater possibilities for embedding in inert materials. Some aminoalcohol derivatives acted as turn-on sensors, fluorescing in the presence of DCP.

Improving The Analysis Of Proteins By Desorption Electrospray Lonization (Desi) By The Addition Of Ammonium Bicarbonate, Elahe Honarvar

Research and Creative Activities Poster Day

The analysis of proteins by Desorption Electrospray Ionization (DESI) is challenged by a mass depend loss in signal response. We show that this loss in sensitivity originates primarily from the incomplete dissolution of proteins into desorptiopn spray solvent. The addition of ammonium bicarbonate is used to improve protein dissolution and we demonstrate beneficial effects this has on protein detection by DESI-MS. We demonstrate improved signal to noise ratio's for all proteins investigated, up to 66kDa. In addition to improvements in signal to noise ratio, changes in charge states were also observed and are described.

Unraveling Structures Of Protection Ligands On Gold Nanoparticle Au68(Sh)32, Wen Wu Xu, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

New low-energy atomic structures of the thiolate-protected gold nanoparticle Au₆₈(SH)₃₂ are uncovered, where the atomic positions of the Au atoms are taken from the recent single-particle transmission electron microscopy measurement by Kornberg and co-workers, whereas the pattern of thiolate ligands on the gold core is attained on the basis of the generic formulation (or rule) of the “divide and protect” concept. Four distinct low-energy isomers, Iso1 to Iso4, whose structures all satisfy the generic formulation, are predicted. Density-functional theory optimization indicates that the four isomers are all lower in energy by 3 to 4 eV than the …

Chemistry And Biochemistry News, Georgia Southern University

Biochemistry, Chemistry & Physics: News & Publications (2012-2023)

• Chemistry Students Make a Splash at GSU Research Symposium

A Maltose-Binding Protein Fusion Construct Yields A Robust Crystallography Platform For Mcl1, Matthew C. Clifton, David M. Dranow, Alison Leed, Ben Fulroth, James W. Fairman, Jan Abendroth, Kateri A. Atkins, Ellen Wallace, Dazhong Fan, Guoping Xu, Z. J. Ni, Douglas S. Daniels, John Van Drie, Guo Wei, Alex B. Burgin, Todd R. Golub, Brian K. Hubbard, Michael H. Serrano-Wu

Chemistry Faculty Publications

Crystallization of a maltose-binding protein MCL1 fusion has yielded a robust crystallography platform that generated the first apo MCL1 crystal structure, as well as five ligand-bound structures. The ability to obtain fragment-bound structures advances structure-based drug design efforts that, despite considerable effort, had previously been intractable by crystallography. In the ligand-independent crystal form we identify inhibitor binding modes not observed in earlier crystallographic systems. This MBP-MCL1 construct dramatically improves the structural understanding of well-validated MCL1 ligands, and will likely catalyze the structure-based optimization of high affinity MCL1 inhibitors.

Toward The Measurement Of Biodistribution Of 18F-Labeled Industrial Chemicals With Positron Emission Tomography (Pet), Katelyenn S. Mccauley

Department of Chemistry: Dissertations, Theses, and Student Research

Plasticizers are added to polymeric materials to increase flexibility and durability, thus they constitute a common, and widely used class of industrial chemicals. Plasticizers have been suspected of a number of adverse health effects including the interference with the endocrine system.¹ These substances have the tendency to migrate to the surfaces of materials, where they can be absorbed, ingested, or inhaled. ⁵ The iniquitousness of plasticizers and the daily contact with polymeric materials has given rise to concern about the toxicity and health effects of these substances. Many long-term and excessive-dose studies have been conducted on many of these …

The 8-Silyloxyquinoline Scaffold As A Versatile Platform For The Sensitive Detection Of Aqueous Fluoride, Xinqi Zhou

Department of Chemistry: Dissertations, Theses, and Student Research

As one of the most essential elements in nature, fluoride has been well known and extensively studied since the 16^th century. Since then the two-edged nature of fluoride in biological systems has been well described. Specifically, moderate fluoride exposure can aid in tooth and bone development, while fluoride overexposure results in the depilating disease known as fluorosis. Because of the side effects upon overexposure of fluoride, there is a need to develop fast and straight forward methods to sensitively and selectively detect and quantify fluoride concentration in drinking water. With this goal in mind and by taking advantage of …

Synthesis Of 1, 2 Amino Alcohols Through Arbuzov Method, Brianne Gibson

Celebrating Scholarship & Creativity Day (2011-2017)

This research involves the synthesis of one diethyl amino-dihydroxy butyl phosphonate which hold characteristics shown to serve as an anti-fungal and anti-microbial agent. The first step of this research involves epoxidation of the phosphonate-containing olefin made using the Arbuzov procedure with crotonaldehyde. The second step synthesizes an oxazolidone using benzyl isocyanate to open the epoxide and cyclize the compound. Hydrolysis of the oxazolidone is performed for the production of the 1, 2 amino-alcohols in the third stage. This step synthesizes the amino-phosphonates. The first and second steps have been completed. Upon successful retrieval of the oxazolidones, the alcohol can be …

On The Mechanism Of Rna Phosphodiester Backbone Cleavage In The Absence Of Solvent, Christian Riml, Heidelinde Glasner, M T. Rodgers, Ronald Micura, Kathrin Breuker

Chemistry Faculty Research Publications

Ribonucleic acid (RNA) modifications play an important role in the regulation of gene expression and the development of RNA-based therapeutics, but their identification, localization and relative quantitation by conventional biochemical methods can be quite challenging. As a promising alternative, mass spectrometry (MS) based approaches that involve RNA dissociation in ‘top-down’ strategies are currently being developed. For this purpose, it is essential to understand the dissociation mechanisms of unmodified and posttranscriptionally or synthetically modified RNA. Here, we have studied the effect of select nucleobase, ribose and backbone modifications on phosphodiester bond cleavage in collisionally activated dissociation (CAD) of positively and negatively …

Synthesis Of Β-Triphosphotriester Pronucleotides, Yousef Beni, Chandravanu Dash, Keykavous Parang

Chemistry Faculty Research

Dinucleoside phosphorochloridite was synthesized from phosphorus trichloride and three nucleoside analogs, 3′-fluoro-2′,3′-dideoxythymidine (FLT), 2′,3′-dideoxy-5-fluoro-3′-thiacytidine (FTC), and 2′,3′-dideoxy-3′-thiacytidine (3TC), in a multistep synthesis. Polymer-bound N-Boc p-acetoxybenzyl 5′-O-2′-deoxythymidine was reacted with dinucleoside phosphorochloridite in the presence of 2,6-lutidine, followed by the reaction with dodecyl alcohol and 5-(ethylthio)-1H-tetrazole, oxidation with tert-butyl hydroperoxide, and acidic cleavage, respectively, to afford the β-triphosphotriester derivatives containing three different nucleosides.

Novel Photodynamic Therapy Agents: Biochemical Analysis, Eboni D. Pullen

Honors College Theses

Bioinorganic photochemistry is a rapidly advancing research area in the field of bioinorganic chemistry. This project seeks to build upon the growing field by synthesizing and analyzing new photodynamic therapy (PDT) agents. There are three major generations of PDT agents. The first generation consists of chemically modified natural hematoporphyrins, which are not of great interest in the phototherapeutic field due to their low distinguishability between tumor cells and healthy cells, and extended skin photosensitivity in patients. The second generation consists of organic dyes, aromatic hydrocarbons, polypyrolics complexes, and semi-conductors, but is also not of much interest due to the same …

The Synthesis And Biological Activity Of Iron Binding Motifs, Rachel Burke

Honors College Theses

Iron is an essential mineral that plays a key role in the oxygen transporting molecule hemoglobin. Iron also helps muscles store and use oxygen. Excess iron in the body can attract electrons, creating harmful oxygen radicals. Iron overload can be caused by several factors such as genetics, age, gender, and having received multiple red blood cell transfusions. Excess iron can lead to many diseases, such as arthritis, liver cirrhosis, heart disease, and several forms of cancer. Iron-chelating therapies work by binding free iron in the bloodstream and by reducing the amount of iron bound in transferrin, the iron transporting molecule. …

Vanadium Substituted Polyoxometalates, Jennifer Bjorklund, Samuel Kim, Rebecca Roesner, Faculty Advisor

John Wesley Powell Student Research Conference

No abstract provided.

Detection And Quantification Of Lead And Copper In Firearm Harvested Ground Venison Intended For Human Consumption, Chris Crown, Manori Perera Faculty Advisor, Given Harper Faculty Advisor

John Wesley Powell Student Research Conference

Most White-tailed Deer (Odocoileus virginianus) in Illinois are harvested with firearms that use lead or copper shotgun slugs or muzzleloader bullets, which may fragment when they strike bone. Lead is a neurotoxin to both humans and animals that scavenge deer that have escaped from hunters, and excess amounts of copper ingestion can impair lipid and DNA function. In a preliminary study in 2014, packets of ground venison from firearm and bow hunters in Illinois were x-rayed, and six out of ten firearm-harvested packets contained possible metal fragments. The purpose of this study is to utilize Anodic Stripping Voltammetry …

Quantification And Scavenging Ability Of Antioxidants In Bottled Tea, Jennifer Prochotsky, Manori Perera Faculty Advisor

John Wesley Powell Student Research Conference

Bottled tea is made from brewed leaves of the Camelia sinensis plant. These leaves contain molecules called polyphenols that have aromatic rings with many alcohol groups. Different fermentation processes of the leaves lead to different types of tea, including black, oolong, green, and white tea. The polyphenols present in bottled tea have antioxidant properties, which have been seen to prevent certain types of diseases. Antioxidants work by stabilizing highly unstable free radicals, which are missing an electron in their orbital. Different studies have concluded contradictory results about which type of tea contains the highest quantity of antioxidants. There has been …

Mechanism Of Assembly Of The Bardet-Biedel Syndrome (Bbs) Complex, Barry M. Willardson

Journal of Undergraduate Research

1. Devon Blake. Devon was the most productive student I have had in my 18 years at BYU. The MEG award helped support his work from January 2013 through May 2014. During this time, Devon co-authored two papers on the effects of cell-type specific deletion of phosducinlike protein 1 (PhLP1) in rod and cone photoreceptor cells (Lai et al. (2013) J. Neurosci. 33, 7941-7951, selected by the Faculty of 1000 as a high-impact paper and Tracy et al. (2014) PLOS One in press). He reported this work in poster form at an international meeting of the Federation of American Society …

Strong Influence Of Coadsorbate Interaction On Co Desorption Dynamics On Ru(0001) Probed By Ultrafast X-Ray Spectroscopy And Ab Initio Simulations, H. Xin, Jerry L. Larue, H. Öberg, M. Beye, M. Dell'angela, J. J. Turner, J. Gladh, M. L. Ng, J. A. Sellberg, S. Kaya, G. Mercurio, F. Hieke, D. Nordlund, W. F. Schlotter, G. L. Dakovski, M. P. Minitti, A. Föhlisch, M. Wolf, W. Wurth, H. Ogasawara, J. K. Nørskov, H. Öström, L. G. M. Pettersson, A. Nilsson, F. Abild-Pedersen

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We show that coadsorbed oxygen atoms have a dramatic influence on the CO desorption dynamics from Ru(0001). In contrast to the precursor-mediated desorption mechanism on Ru(0001), the presence of surface oxygen modifies the electronic structure of Ru atoms such that CO desorption occurs predominantly via the direct pathway. This phenomenon is directly observed in an ultrafast pump-probe experiment using a soft x-ray free-electron laser to monitor the dynamic evolution of the valence electronic structure of the surface species. This is supported with the potential of mean force along the CO desorption path obtained from density-functional theory calculations. Charge density distribution …

Imidazolium Salts As Reaction Media For The Preparation Of Metal Halide Cluster Networks, Stephanie K. Gnewuch

Undergraduate Honors Thesis Projects

This study investigated two different schemes of imidazolium and carboxylate salts to assess their use in preparing metal halide cluster networks. The first scheme used salts of 1-ethyl-3-methylimidazolium [EMIM]⁺ and 1-butyl-3-methylimidazolium [BMIM]⁺ as the cations and benzene-1,3,5-tricarboxylate [TMA]-, benzene 1,3-dicarboxylate [IPA]-, and benzene-1,4-dicarboxylate [TPA]- as the anions. The anions are commonly used in porous inorganic materials synthesis, as the size of the cation has been shown to often impact the final structure of the materials. The anions are common bridging ligands used to create network solids. The second scheme used 1,3-dimethylimidazolium triflate [DMIM]⁺ [OTf]^- and sodium …