Assemblies And Properties Of Asymmetric Supercapacitors Based On Wo3/Carbon Cloth,
2018
Key Laboratory of Catalysis and Materials Science of the State Ethnic Affairs Commission and Ministry of Education, Hubei Province, South-Central University for Nationalities, Wuhan 430074, Hubei,China;
Assemblies And Properties Of Asymmetric Supercapacitors Based On Wo3/Carbon Cloth, Wen-Ke Shao, Lei Zhao, Chao Liu, Yan-Ying Dong, Yuan-Jie Zhu, Qiu-Fan Wang
Journal of Electrochemistry
The demand for a new generation of flexible, portable, and high-capacity power sources increases rapidly with the development of advanced wearable electronic devices. One dimensional (1D) nanowires structures have been demonstrated as one of the most ideal electrode materials in energy storage systems due to their advantages in both micorstructures and their high surface areas. Here we report a simple process for large-scale fabrication of self-standing composite film electrodes composed of WO3 nanorods on carbon cloth. In order to improve the energy density of supercapacitor, we assembled an asymmetric supercapacitor using WO3 nanorods and activated carbon cloth as …
Influences Of Na-Mn Ratio On Electrochemical Performances And Intercalation-Deintercalation Processes Of Sodium Ion In NaXMno2,
2018
1. School of Chemistry of and Chemical Engineering, Guangxi University, Nanning 530004, China;
Influences Of Na-Mn Ratio On Electrochemical Performances And Intercalation-Deintercalation Processes Of Sodium Ion In NaXMno2, Yong-Chun Xie, Cheng Wang, Fang Jiang, Yang Yang, Jing Su, Yun-Fei Long, Yan-Xuan Wen
Journal of Electrochemistry
In this work, NaxMnO2 was synthesized by a solid-state reaction. The influences of Na:Mn ratio on the structure, morphology and electrochemical performance, and sodium ion intercalation/deintercalation processes were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge test. The prepared NaxMnO2 was mainly composed of Na0.7MnO2 and Na0.91MnO2, and the content of Na0.91MnO2 increased with the increase of Na:Mn ratio. However, the activation energy values of surface membrane diffusion, interfacial electrochemical reaction and …
Platinum@Hexaniobate Nanopeapods: Sensitized Composite Architectures For Photocatalytic Hydrogen Evolution Under Visible Light Irradiation,
2018
University of New Orleans
Platinum@Hexaniobate Nanopeapods: Sensitized Composite Architectures For Photocatalytic Hydrogen Evolution Under Visible Light Irradiation, Clare Davis-Wheeler Chin
LSU New Orleans Theses and Dissertations
Hydrogen fuel is one of the most important areas of research in the field of renewable energy development and production. Hydrogen gas can be generated by fuel cells, water electrolyzers, and heterogeneous nanoscale catalysts. It can be burned to directly release chemical energy or condensed for storage and transport, providing fuel for combustion devices or storing excess energy generated by renewable sources such as wind turbines and concentrated solar power assemblies. While platinum is the most active catalyst for hydrogen reduction, its high cost significantly deters its utilization in advanced photocatalytic materials. One approach to mitigating this expense is optimizing …
Fabrication Of Mnox/Mwcnts-Gc Nanocatalyst For Oxygen Evolution Reaction,
2018
The British University in Egypt
Fabrication Of Mnox/Mwcnts-Gc Nanocatalyst For Oxygen Evolution Reaction, Yaser M. Asal Mr, Islam M. Al-Akraa Dr, Amr M. Arafa Eng.
Chemical Engineering
Manganese oxide (MnOx) and multiwalled carbon nanotubes (MWCNTs) are intended to modify the GC electrode for oxygen evolution reaction (OER). Optimization of MnOx loading is carried out and the deposition of 55 cycles was sufficient to obtain the highest activity toward OER. The stability of the catalyst is enhanced by the addition of MWCNTs. As a result, an amount of 22 kWh/Kg of O2 of energy is saved. Several techniques including cyclic voltammetry, linear sweep voltammetry, chronoamperometry, chronopotentiometry, field-emission scanning electron microscopy, and energy dispersive X-ray spectroscopy will be combined to track the catalyst activity and to determine its …
Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions,
2018
Purdue University
Examining The Effects Of Amino And Thiolate Ligands On The Reactivity And Selectivity Of Palladium On Carbon In Hydrogenation Reactions, Eric Liu, Christina Li
The Summer Undergraduate Research Fellowship (SURF) Symposium
Heterogeneous catalysts are used widely by chemical and energy industries because they show high reactivity but often suffer from lack of selectivity. On the other hand, ligands are commonly used in homogeneous catalysts to control the reactivity and selectivity; however, the effects of the ligands on the steric and electronic properties of heterogeneous catalysts are less understood. We examine the effects of four different ligands: 1-adamantanethiol, 1-adamantylamine, 1-dodecanethiol, and 1-dodecylamine, for the commercial hydrogenation catalyst palladium on carbon. Hydrogenation reactions are used as a screening tool to see the behavior that the different catalysts exhibit in the presence of unsaturated …
Piezoresponse, Mechanical, And Electrical Characteristics Of Synthetic Spider Silk Nanofibers,
2018
Utah State University
Piezoresponse, Mechanical, And Electrical Characteristics Of Synthetic Spider Silk Nanofibers, Nader Shehata, Ishac Kandas, Ibrahim Hassounah, Patrik Sobolčiak, Igor Krupa, Miroslav Mrlik, Anton Popelka, Jesse Steadman, Randolph V. Lewis
Biology Faculty Publications
This work presents electrospun nanofibers from synthetic spider silk protein, and their application as both a mechanical vibration and humidity sensor. Spider silk solution was synthesized from minor ampullate silk protein (MaSp) and then electrospun into nanofibers with a mean diameter of less than 100 nm. Then, mechanical vibrations were detected through piezoelectric characteristics analysis using a piezo force microscope and a dynamic mechanical analyzer with a voltage probe. The piezoelectric coefficient (d33) was determined to be 3.62 pC/N. During humidity sensing, both mechanical and electric resistance properties of spider silk nanofibers were evaluated at varying high-level …
Synthesis And Characterization Of Block Copolymers For Shear Force Responsive Materials And Sugar Conjugated Fluorescent Probes,
2018
Missouri State University
Synthesis And Characterization Of Block Copolymers For Shear Force Responsive Materials And Sugar Conjugated Fluorescent Probes, Jacob Ryan Blankenship
Graduate Theses/Dissertations
Herein, I present my work towards two goals: shear force-responsive materials and sugarconjugated fluorescent probes for bacterial identification applications. The first work is on the development of stimuli-responsive polymers that allow for precise control over the release of encapsulated material. Stimuli-responsive polymers are becoming increasingly important in drug delivery and other applications. However there have been few reports on shear force-responsive micellar systems. I show the synthesis, and characterization by 1H and 13C NMR of four macro-chain transfer agents (macro-CTAs), one of which has not been previously reported. The resulting macro-CTAs were used in polymerization of vinyl acetate …
Removal Of Acid Yellow 25 From Aqueous Solution By Chitin Prepared From Waste Snow Crab Legs,
2018
Southern Illinois University Edwardsville
Removal Of Acid Yellow 25 From Aqueous Solution By Chitin Prepared From Waste Snow Crab Legs, Chin-Chuan Wei, Inoka K. Pathiraja, Emily Fabry, Kyle Schafer, Nick Schimp, Tuo-Ping Hu, Lawrence P. Norcio
SIUE Faculty Research, Scholarship, and Creative Activity
Acid Yellow 25 (AY25) is used in the textile industry for dyeing of natural and synthetic fibers, and is also used as a coloring agent in paints, inks, plastics, and leathers. Effluents from such industries are major sources of water pollution. Hence, it is important to find simple, efficient, and inexpensive ways to remove these dyes from wastewater. Here, we determined the suitability of chitin extracted from waste crab legs as an adsorbent for removing AY25 dye. The adsorption kinetics was modeled using pseudo-first order, pseudo-second order, and intraparticle diffusion equations to determine the rate controlling step. Results showed that …
Development Of Mof@Polymer Composite Materials Through Bottom-Up Self-Assembly Techniques,
2018
University of New Mexico
Development Of Mof@Polymer Composite Materials Through Bottom-Up Self-Assembly Techniques, Roberto Christian Arbulu
Chemistry and Chemical Biology ETDs
MOF-based mixed matrix membranes (MMMs) are a promising new class of MOF/polymer composite materials. Currently, fabrication of MMMs is based on top-down methods with limited control over MOF positioning, integration, or morphology. This work focuses on the growth of well-defined one-dimensional (1-D) MOF nanostructures within the pores of a nanoporous polymer template, either commercially available or through the self-assembly of block co-polymers having tailor-designed surface functionalities. Studies were conducted using zeolitic imidazole framework-8 (ZIF-8) and polycarbonate track etched (PCTE) membranes, which demonstrated the feasibility of the outlined approach, and revealed the formation of distinct super- and nanostructures with controlled morphologies …
Molecular Assembly Of Monolayer-Protected Gold Nanoparticles And Their Chemical, Thermal, And Ultrasonic Stabilities,
2018
Western Kentucky University
Molecular Assembly Of Monolayer-Protected Gold Nanoparticles And Their Chemical, Thermal, And Ultrasonic Stabilities, Steven Ray Isaacs
Masters Theses & Specialist Projects
Gold monolayer-protected nanoclusters (MPCs) with average diameters of 1-5 nm protected by alkane- and arenethiolates were synthesized. Mixed-monolayer protected nanoparticles (MMPCs) were prepared by functionalizing hexanethiolate-protected MPCs with either 11-mercaptoundecanoic acid (MUA-MMPC), 11-mercaptoundecanol (MUO-MMPC), or 4-aminothiophenol (ATP-MMPC) using ligand place exchange. Presentation of various chemical reagents such as nucleophile, acid, or base and change in physical environment through ultrasonic and thermal irradiation resulted in changes to particles and their physical properties. Thermogravimetric analysis (TGA) was used to measure maximum temperature of the derivated thermogravimetric peaks (Tmax,DTG) as a means of comparing temperature dependence of mass loss. The absorption spectrum within …
Thermosetting Polymers Via Azide Alkyne Cycloaddition,
2018
University of Southern Mississippi
Thermosetting Polymers Via Azide Alkyne Cycloaddition, Richard H. Cooke Iii
Dissertations
This dissertation exploits properties inherent to azide-alkyne cycloaddition and applies practical solutions to difficult problems. Chapter II addresses structure-property relationships in glassy azido-alkyne matrices by varying the identity of the central linkage within tetrapropargyl bis-aniline-type crosslinkers, and by the addition or omission of Cu(I) catalyst. This systematic study showed that an ether or methylene linkage yielded lower melting tetrapropargyl crosslinkers that were soluble in, and produced homogeneous, networks when cured with, a standard azido resin, di(3-azido-2-hydroxypropyl) ether of bisphenol-A; in contrast, a sulfone linkage yielded a relatively insoluble crosslinker and poorly dispersed, heterogeneous networks when reacted with the same …
The Effect Of Semiconductor Materials On Solar Cell Efficiency,
2018
Rockdale Magnet School
The Effect Of Semiconductor Materials On Solar Cell Efficiency, Shivam Vohra
The International Student Science Fair 2018
The purpose of this project was to increase the efficiency of solar cells through the use of quantum dots and nanoparticles. These substances would increase the efficiency of the semiconductor. The research hypothesis stated that if lead iodide was applied to the semiconductor, then the average voltage, amperage, power, and efficiency of the solar cells would increase. The procedure for this project involved creating a lead iodide and titanium dioxide mixture with dimethylformamide, ethanol, acetylacetone, and Triton X-100 in an autoclave. Then, two milliliters of each solution were applied to cadmium selenide quantum dots to make four different solutions. Each …
Feco2o4 As An Anode Material For Lithium Ion Batteries,
2018
National Junior College
Feco2o4 As An Anode Material For Lithium Ion Batteries, Chelsea Wong
The International Student Science Fair 2018
Lithium ion batteries (LIBs) are commonly found in many portable electronic appliances due to their ability to be rechargeable. Currently, commercial anodes in Li-ion batteries (graphite) have a theoretical capacity of around 372 mAh/g, while FeCo2O4 that will be investigated as the anode material has a theoretical capacity of 901.985mAh/g, more than double of the current commercial anode’s capacity. Earlier work done by Sharma et al also showed that FeCo2O4 has a very promising initial capacity of 827mAh/g. As such, the engineering goal is to produce a battery that will have a higher capacity than the current commercial Li-ion batteries …
An Entirely New Molecular Glue For Mof Using Unusual Structural Transformation Of A Coordination Polymer,
2018
Korea Science Academy
An Entirely New Molecular Glue For Mof Using Unusual Structural Transformation Of A Coordination Polymer, Sukwoo Jung, Hangyeol Kim, Junseok Ahn
The International Student Science Fair 2018
In this research, an entirely new molecular glue is reported. This ‘coordination polymer glue’ is synthesized from zinc metal and BDC-NPE(2,5-bis{4-[1-(4-nitrophenyl)ethylamino]butoxy}terephthalic acid). Molecular glue transforms from 1D coordination polymer to a 3D cross-linked framework, resulting in a phase change of solution to solid. The carboxylate group of this glue makes the preformed MOF bind to its framework. Therefore, when the solution of molecular glue is mixed with preformed MOF powder and heated, homogeneous and thin MOF film – MOF/ZnNPE film – is fabricated. The film is irrelevant to the kind of its substrate, and its thermal stability was enhanced in …
Co3(Hcoo)6@Rgo As A Promising Anode For Lithium Ion Batteries,
2018
State Key Laboratory for Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, iChem (Collaborative Innovation Center of Chemistry for Energy Materials), Xiamen University, Xiamen 361005, China;
Co3(Hcoo)6@Rgo As A Promising Anode For Lithium Ion Batteries, Heng Jiang, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong
Journal of Electrochemistry
Metal–organic framework(MOF) is a kind of novel electrode materials for lithium ion batteries. Here, a composite material Co3(HCOO)6@rGO was synthesized for the first time by in situ loading of Co3(HCOO)6 on rGO (reduced oxide graphene) through a solution chemistry method. As an anode material for lithium ion batteries, it exhibited an excellent cycle stability as well as a large reversible capacity of 926 mAh·g-1 at a current density of 500 mA·g-1 after 100 cycles within the voltage range of 0.02 ~ 3.0 V vs. Li/Li+ with a good rate capability. …
Chemical Stability Investigations Of Catalyst Layer In Pemfc,
2018
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China; University of Chinese Academy of Sciences, Beijing 100039, China;
Chemical Stability Investigations Of Catalyst Layer In Pemfc, Yan-Yan Gao, Ming Hou, Yong-Yi Jiang, Dong Liang, Jun Ai, Li-Min Zheng
Journal of Electrochemistry
This work was intended to study the effect of free radicals on the chemical stability of catalyst layer via ex situ accelerated stress test (AST). Fenton reagent was used as the free radical provider in this research. Apart from the decomposition of Nafion in catalyst layer, the agglomerated Pt nanoparticles and the corroded carbon support were also observed after being treated in Fenton reagent for 100 h. Firstly, the existence of fluoride (F) ions evidenced the chemical decomposation of Nafion after being attacked by trace radical species, which was supported by the intensity decrease in the C-F stretching and vibration …
Recent Progress For Fe-N-C Electrocatalysts In Alkaline Fuel Cells,
2018
College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, Zhejiang, China;
Recent Progress For Fe-N-C Electrocatalysts In Alkaline Fuel Cells, Xin Deng, Heng-Quan Chen, Ye Hu, Qing-Gang He
Journal of Electrochemistry
Fuel cells are highly recommended nowadays due to their intrinsic advantages such as high energy conversion efficiency, nearly no pollution, and convenient operation. With the development of anion exchange membrane, alkaline fuel cells have gone through a renaissance thanks to their superiorities such as faster reaction kinetics, wider choices for both fuels and electrocatalysts. It is essential to find an appropriate electrocatalyst for oxygen reduction reaction (ORR) to improve the performance of alkaline fuel cells. Further commercialization of the widely used Pt-based materials has suffered from disadvantages such as scarcity and high cost. As alternatives to largely investigated Pt-based materials, …
A Study Of Pulse Electrodeposition On Suppressing The Formation Of Lithium Dendrite,
2018
State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China;
A Study Of Pulse Electrodeposition On Suppressing The Formation Of Lithium Dendrite, Wen-Jun Guo, Zi-Qiong Li, Ruo-Hao Ke, Dong-Fang Niu, Heng Xu, Xin-Sheng Zhang
Journal of Electrochemistry
A pulse charge method was used to suppress the formation of lithium dendrite on the copper electrode in 0.5 mol·L-1 LiBr/propylene carbonate (PC) electrolyte. The surface variation of lithium deposition was investigated by scanning electron microscope and impedance measurement. The SEM test showed that the lithium dendrites were formed on the copper electrode during the traditional process of electrodeposition. However, the formed dendrite was suppressed by pulse charge method. The results of the impedance measurement confirmed that the pulse electrodeposition could suppress the dendrite under the optimized duty ratio (0.5). The long single pulse deposition time decreased the resistance …
Pt/G-C3N4 Nanosheet For Visible Light-Induced Enhancement Of The Activity For Formic Acid Electro-Oxidation,
2018
Institute of Advanced Chemical Power Sources, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China;School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China;
Pt/G-C3N4 Nanosheet For Visible Light-Induced Enhancement Of The Activity For Formic Acid Electro-Oxidation, Yong-Rong Sun, Chun-Yu Du, Guo-Kang Han, Ya-Jing Wang, Yun-Zhi Gao, Ge-Ping Yin
Journal of Electrochemistry
By using graphitic carbon nitride nanosheet (g-C3N4 nanosheet) as a support,Pt/g-C3N4 nanosheet catalyst was fabricated by microwave assisted polylol process. The nanoparticles size,composition,structure and optical properties of Pt/g-C3N4 nanosheet were characterized by TEM,XRD,XPS and UV-Vis diffuse reflectance spectroscopy. Comparing with the catalytic activities toward formic acid electro-oxidation under dark and visible light illumination,the superior activity of Pt/g-C3N4 nanosheet catalyst was achieved under visible light illumination. This visible light-driven enhancement in the formic acid performance could be attributed to the plasmon-induced electron-hole separation on g-C3N4 with …
Preparation And Electrochemical Performance Of Ag-Tio2-Mno2 Composites,
2018
Beijing Key Laboratory for Green Catalysis and Separation, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, China;
Preparation And Electrochemical Performance Of Ag-Tio2-Mno2 Composites, Ling-Xiao Zhang, Hui-Hui Zhao, Li-Juan Zhang, Yu Fu
Journal of Electrochemistry
The silver-titanium dioxide co-modified manganese dioxide (Ag-TiO2-MnO2) cathode material was prepared through high temperature solid state reaction. The microstructure, phase composition and electrochemical performance of the prepared samples were characterized by X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), X-ray photoelectron spectroscopy (XPS), Energy-dispersive X-ray spectroscopy (EDS), Cyclic voltammetry (CV), galvanostatic discharge and electrochemical impedance spectroscopy (EIS). Results showed that the unmodified and Ag-TiO2 modified MnO2 samples both exhibited β-MnO2 structurebut with different morphologies. The EDS mapping results revealed that Ag was uniformly dispersed on the surface of …
