Materials Chemistry Commons^™

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 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.

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 …

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 …

Synthetic Methods Of Cts And Czts Nanocrystals, Rachel R. Bohling, Michael M. Davis, Blake J. Gerold, Ted M. Pappenfus

Undergraduate Research Symposium 2015

The synthesis of various morphologies of copper zinc tin sulfide (Cu2ZnSnS4) and copper tin sulfide (Cu2SnS3) nanocrystals were explored to find a more energy efficient synthesis. Reactions were all carried out at 220°C under either inert atmospheres or normal conditions. Variations in synthetic methods included reaction time and solvents used. Products were analyzed with powder X-Ray diffraction and compared to simulated powder patterns of zincblende and wurtzite nanocrystals. The synthesis of CTS nanocrystals required the reaction to be heated to 220°C overnight under an inert atmosphere. The reaction used for the synthesis of CZTS nanocrystals required less energy and only …

Bio-Crosslinking Of Starch Films With Oxidized Sucrose, Hazal Canisag

Department of Textiles, Merchandising and Fashion Design: Dissertations, Theses, and Student Research

In this work, corn starch films were crosslinked with a novel bio-based agent; oxidized sucrose and their strength and stability were improved. Although starch is an inexpensive, biodegradable and abundant source, industrial applications of starch films are limited due to their poor mechanical properties. Crosslinking is one of the most common methods to enhance the mechanical properties of starch films. However, most of the available crosslinkers, such as gluteraldehyde, phosphorus oxychloride, sodium trimetaphosphate, and epichlorohydrin, are either toxic, expensive or with low crosslinking efficiencies. Oxidized sucrose, which is derived by periodate cleavage, has aldehyde groups in the structure and this …

Structural Patterns At All Scales In A Nonmetallic Chiral Au_133(Sr)_52 Nanoparticle, Chenjie Zeng, Yuxiang Chen, Kristin Kirschbaum, Kannatassen Appavoo, Matthew Y. Sfeir, Rongchao Jin

Publications and Research

Structural ordering is widely present in molecules and materials. However, the organization of molecules on the curved surface of nanoparticles is still the least understood owing to the major limitations of the current surface characterization tools. By the merits of x-ray crystallography, we reveal the structural ordering at all scales in a super robust 133–gold atom nanoparticle protected by 52 thiolate ligands, which is manifested in self-assembled hierarchical patterns starting from the metal core to the interfacial –S–Au–S– ladder-like helical “stripes” and further to the “swirls” of carbon tails. These complex surface patterns have not been observed in the smaller …

Electrochemical Monitoring Of Cell Wall-Regulated Transient Extracellular Oxidative Burst From Single Plant Cells, Jun-Tao Liu, Yan-Ling Liu, Zhi Cheng, Shi-Jing Chen, Wei-Hua Huang

Journal of Electrochemistry

Oxidative burst by rapid, transient generation of reactive oxygen species (ROS) is a fundamental process for plant disease defense and signal transduction. ROS can be protective or toxic depending on their concentrations, and critical balance between ROS production and scavenging is regulated by complex and perfect mechanisms in plant cells. However, the process of rapid and transient ROS burst from plant cells and their regulatory mechanisms are far from being completely understood, owing to the methodological obstacles in real-time monitoring such a fast process. In this work, we showed the application of microelectrode electrochemistry with high spatiotemporal resolution to monitor …

Novel Dna Electrochemical Biosensor For K-Ras Point Mutation Detection Based On Dna Polymerase I, Li-Qing Lin, Cheng-Fei Zhao, Zhou-Qian Jiang, Shao-Huang Weng, Xiao-Lan Xie, Xin-Hua Lin

Journal of Electrochemistry

In this article, we developed a novel DNA electrochemical sensor for obtaining a current-time curve based on DNA polymerase I. The capture probes were fixed on the Au electrode by Au interacting with -SH, and then hybridized with the K-ras mutant target DNA as far as one base before the mutation site. After hybridizing the K-ras mutant or wild target DNA, the resulting assembly reacted with the dUTP-biotin in the presence of DNA polymerase I. Then avidin-HRP combined the dUTP-biotin on the electrode. The proposed electrode was applied for detection in TMB solution by electrochemical technology. The experimental results showed …

A Novel Nitrite Sensing Electrode Based On Au/Fe3O4/Chitosan Nanocomposite, Ying Dong, Yong Wang, Huan-Huan Xing, Jian-Ying Qu

Journal of Electrochemistry

A novel nitrite sensing electrode based on gold nanoparticles and iron oxides (Fe₃O₄) magnetic nanoparticles was fabricated with chitosan as the protective film on glassy carbon matrix. Experiment results showed that the sensing electrode exhibited good electrocatalytic activity toward oxidation of nitrite, and the oxidation peak current increased linearly with the concentration of nitrite varying from 5.0×10^-6 to 2.0×10^-3 mol·L^-1 (R=0.9996) with a detection limit of 7.1×10^-7 mol·L^-1 (S/N=3). The sensing electrode exhibited good sensitivity, selectivity and repeatability.

Electrochemiluminescence Assay Based On Bipolar Electrode For Bioanalysis, Mei-Sheng Wu, Jing-Juan Xu, Hong-Yuan Chen

Journal of Electrochemistry

Bipolar electrodes (BPEs) are electronic conductors which are usually embedded into microchannels. The potential difference at the BPE/solution interface is obtained by applying a voltage at the two ends of the microchannel. When it reaches a critical value, the redox reaction takes place at both poles of the BPE simultaneously. Compared with other detection methods, the electrochemiluminescence (ECL) platform based on BPE possesses the advantages of concentration enrichment, high sensitivity, low cost, portable sensor system, no need for a light source, which is quite suitable for bioanalysis. This paper reviews the ECL-BPE strategy for bioanalysis and proposes the future research …

Electrochemiluminescence Biosensors Based On The Signal Amplification Of Co-Reactants, Hai-Jun Wang, Li-Juan Xiao, Ying He, Xin-Ya Jiang, Ya-Li Yuan, Ying Zhuo, Ya-Qin Chai, Ruo Yuan

Journal of Electrochemistry

Using co-reactants to enhance the luminous efficiency of luminophores is a common, convenient and effective method in the construction of the electrochemiluminescence (ECL) biosensors. However, the different methods of introducing co-reactants in the construction of the ECL biosensors will bring different amplification effects. In this review, several signal amplification methods through co-reactants are summarized: 1) Adding the co-reactants directly into the detection solution; 2) Immobilizing the co-reactants onto the electrode surface; 3) Using enzymatic reaction to generate co-reactants in situ around the electrode surface. And then, the outlook of the ECL signal amplification strategy is proposed on those bases.

An Enzymatic Ethanol/O2 Biofuel Cell Powered By Commercial Vodka Fuel, Yi-Ming Yan, Lan-Qun Mao

Journal of Electrochemistry

This study demonstrates the performance of a new type alcohol/O₂ biofuel cell assembled by using alcohol dehydrogenase (ADH) and bilirubin oxidase (BOD) as the biocatalysts of the bioanode and the biocathode for the bioelectrocatalytic oxidation of alcohol and reduction of oxygen, respectively. To construct the bioanode and the biocathode, single-walled carbon nanotubes (SWCNTs) were used. In the bioanode, SWCNTs were used as the supporting materials for both methylene green (MG) which was used as the electrocatalyst for the oxidation of NADH and ADH. The as-constructed MG/ADH/SWCNTs-based bioanode exhibits a good activity toward the bioelectrocatalytic oxidation of ethanol. In the …

Sensitive Detection Of Hydroxyl Radical Based On Silver-Enhanced Gold Nanoparticle Label, Yan Yang, Peng Yu, Xiao-Hua Zhang, Jin-Hua Chen

Journal of Electrochemistry

A novel DNA-based electrochemical sensor has been successfully constructed for sensitive detection of hydroxyl radical (·OH) based on the silver-enhanced gold nanoparticle label. Thiolated DNA1 was firstly immobilized on the gold electrode through Au—S bonds. The ·OH generated from Fenton reaction could induce serious oxidative damage of the DNA1 layer on the electrode surface. Then DNA2-functionalized gold nanoparticles (DNA2-AuNPs) were linked on the electrode through the hybridization between DNA2 and undamaged DNA1. Based on the catalytic reduction of silver ion by AuNPs, a silver layer was formed on the surface of AuNPs. The quantitative assay of ·OH was carried out …

A Multi-Channel Electrochemical Immunosensing System With Polyhrp-Based Signal Amplification For The Detection Of Tumor Markers, Wang-Ping Deng, Yan-Zhi Dou, Jing Su, Lin Hao, Shi-Ping Song, Chun-Hai Fan

Journal of Electrochemistry

We have developed a multi-channel electrochemical immunosensing system for the detection of α-fetoprotein (AFP). The sensing system consisted of carbon screen-printed electrode (SPCE) arrays and polyHRP-based signal amplification probes. AFP antigens could bind to both capture antibodies immobilized on electrode arrays ant detection antibodies (anti-AFP IgG developed in rabbit). The anti-rabbit IgG conjugated to poly-horseradish peroxidase were used as a signaling probe to bind to the immuno-complex. The current signals were harvested by a home-made multi-channels electrochemical detector. AFP could be detected in the concentration ranges of 64 pg·mL^-1 ~ 250 ng·mL^-1. The detection limit was as …

Fabrication And Application Of Cytochrome P450 Electrochemcial Biosensor In Drug Metabolism, Xuan Xu, Ju-Sheng Lu, Song-Qin Liu

Journal of Electrochemistry

The process of drug metabolism plays an important role in drug efficacy and toxicity in vivo. Thus, the development of cheap, continent, rapid and high-throughput method for drug metabolism studies has great guiding significance for the design of new drugs, the determination of drug dosage and the detection of clinical drugs. Since the key role played by Cytochrome P450 (CYP450) in phase-I drug reaction, the constructed CYP450 enzyme biosensor can be used for the initial screening of drugs. It is found that the replacement of coenzyme NADPH with an electrode is to provide two electrons demanded in the catalytic reaction. …

Electrochemical Detection Of L-Cysteine Based On Iron Phthalocyanine/Nitrogen-Doped Graphene Modified Electrodes, Jing-Jing Xiao, Hui-Ying Xu, Li Xu, Bao-Hong Liu

Journal of Electrochemistry

In this study, we report a facile method to develop FePc/N-G hybrid modified electrode for the detection of L-cysteine. The electrochemical sensor was characterized by cyclic voltammetry and amperometric response. The sensor exhibited a wider linear range with rapid response which has outperformed pure FePc/GCE, highlighting the important role of nitrogen doped graphene as substrate for improving the electrochemical response property.

Naio4 Oxidation Of Mussel Adhesive Protein Film And Its Corrosion Protection For Mg-1.0ca Alloy, Rui-Qing Hou, Ping-Li Jiang, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

The effect of oxidation of mussel adhesive protein (Mefp-1) film on the corrosive resistance for Mg-1.0Ca alloy was investigated by scanning electron microscopy (SEM), atom force microscopy (AFM), electron probe microanalysis (EPMA), Infrared reflection absorption spectroscopy (IRAS) and electrochemical methods. The results showed that the NaIO₄ induced oxidation of the pre-formed Mefp-1 film with porous morphology involved structural change of the DOPA group in the protein and resulted in a more uniform film with net-like morphology. The protein film without oxidation had an increasing resistance for the corrosion of Mg-1.0Ca alloy up to 7 days exposure. After oxidation, Epit …

Nanosized Fe2O3 On Three Dimensional Hierarchical Porous Graphene-Like Matrices As High-Performance Anode Material For Lithium Ion Batteries, Qin-Wei Zhang, Yun-Yong Li, Pei-Kang Shen

Journal of Electrochemistry

Ferric oxide (Fe₂O₃) as a promising anode material for lithium ion battery is due to its high theoretical capacity (1007 mAh·g^-1), earth abundance and low cost. The nanosized Fe₂O₃ on the three dimensional hierarchical porous graphene-like network (denoted as Fe₂O₃-3D HPG) has been synthesized by homogeneous precipitation and heat treatment. The 3D HPG can provide a highly conductive structure in conjunction to support well contacted Fe₂O₃ nanoparticles, and effectively enhance the mechanical strength of the matrices during volume changes, as well as improve the …

Preparation And Properties Of Titanium Based Metal Oxide Electrodes For Ammonia Nitrogen Wastewater Treatment, Xue Li, Meng Xue, Ling Huang, Jun-Tao Li, Shi-Gang Sun

Journal of Electrochemistry

In this paper, four types of titanium based metal oxides electrodes were prepared by thermal decomposition method: Ti/SnO₂+Sb₂O₃, Ti/SnO₂+Sb₂O₃/SnO₂+IrO₂, Ti/SnO₂+Sb₂O₃/SnO₂+RuO₂, Ti/SnO₂+Sb₂O₃/SnO₂+CeO₂. The XRD results show that CeO₂ in Ti/SnO₂+Sb₂O₃/SnO₂+CeO₂ displayed a good crystal structure, and there was no significant oxygen evolution reaction occurred after electrolytic oxidation. Compared with the other three electrodes, the Ce-doped …

Effects Of Etchants On Surface Morphologies And Electrochemical Performance Of Iro2-Mno2 Anodic Nano-Coatings, Qing-Guo Fan, Zhi-Guo Ye, Hui-Min Meng, Chun-Min Lu

Journal of Electrochemistry

The IrO₂-MnO₂ anodic nano-coatings were prepared by the traditional thermal decomposition method on the different surfaces of Ti substrates pretreated by different etchants (HCl, H₂SO₄, C₂H₂O₄ and HF). Surface morphologies and electrochemical performance of the Ti based IrO₂-MnO₂ anodic coatings were investigated by field emission scanning electron microscopy (FESEM), cyclic voltammetry (CV) and polarization techniques. Analysis showed that the denser IrO₂ nano-particles with longer dimensions were obtained at the IrO₂-MnO₂ anodic coating surfaces on the Ti substrates etched by HF and …

The Stoichiometry Of Metal Assisted Etching (Mae) Of Si In V2o5 + Hf And Hooh + Hf Solutions, Kurt W. Kolasinski, William B. Barclay, Yu Sun, Mark Aindow

Chemistry Faculty Publications

No abstract provided.

Fabrication And Characterization Of A Vertically-Oriented Graphene Supercapacitor, Patrick R. Rice, Jiaxin Cui, Ahmad Badr, Michael M. Oye, Jessica E. Koehne, Meyya Meyyappan

STAR Program Research Presentations

Supercapacitors, otherwise known as electrical double layer capacitors, are a new type of electrochemical capacitor whose storage capacity is governed by two principals: the electrostatic storage achieved by a separation of charge at the interface of an electrode with an electrolytic solution, and pseudocapacitance, whose electrical energy is achieved by faradaic redox reactions. This project reports the synthesis and characterization of vertically-oriented graphene grown on copper substrates as electrodes in electric double-layer capacitor. Graphene is a two-dimensional pure carbon material with a high potential for energy storage. With vertically-grown graphene, an exponentially-larger surface area is made available, allowing an increase …

Unraveling The Mechanism Of Selective Ion Transport In Hydrophobic Subnanometer Channels, Hui Li, Joseph S. Francisco, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Recently reported synthetic organic nanopore (SONP) can mimic a key feature of natural ion channels, i.e., selective ion transport. However, the physical mechanism underlying the K⁺/Na⁺ selectivity for the SONPs is dramatically different from that of natural ion channels. To achieve a better understanding of the selective ion transport in hydrophobic subnanometer channels in general and SONPs in particular, we perform a series of ab initio molecular dynamics simulations to investigate the diffusivity of aqua Na⁺ and K⁺ ions in two prototype hydrophobic nanochannels: (i) an SONP with radius of 3.2 Å, and (ii) single-walled …