Download or read book Molecular Design of Electrode Surfaces and Interfaces For Optimized Charge Transfer at Transparent Conducting Oxide Electrodes and Spectroelectrochemical Sensing written by Fathima Saneeha Marikkar and published by . This book was released on 2006 with total page 1106 pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACTThis dissertation has focused on i) optimizing charge transfer rates at indium-tin-oxide (ITO) electrodes, and ii) characterization of the supramolecular structure and properties of ultra thin surface modifier films on modified electrodes for various device applications.Commercial ITO surfaces were modified using conducting polymer thin film architectures with and without various chemical activation procedures. Ferrocene derivatives were used as redox probes, which showed dramatic changes in electron transfer rate as the SA-PANI/PAA layers were added to the ITO surface. Highest rates of electron transfer were observed for DMFc, whose oxidation potential coincides with the potential region where these SA-PANI/PAA films reach their optimal electroactivity. Apparent heterogeneous electron transfer rate constants, kS, measured voltammetrically, were ca. 10 x higher for SA-PANI/PAA films on ITO, versus clean ITO substrates. These films also showed linear potentiometric responses with retention of the ITO transparency with the capability to create smoothest films using an aqueous deposition protocol. ITO electrodes were also modified via chemisorption of carboxy functionalized EDOTCA and electropolymerization of and PEDOTCA/PEDOT copolymers, when properly optimized for thickness and structure, enhance voltammetrically determined electron transfer rates (kS) to solution probe molecules, such as dimethylferrocene (DMFc). Values of kS≥ 0.4 cmsec-1, were determined, approaching rates seen on clean gold surfaces. ITO activation combined with formation of these co-polymer films has the effect of enhancing the electroactive fraction of electrode surface. The electroactivity and spectroelectrochemistry of these films helped to resolve the electron transfer rate mechanism and enabled the construction of models in combination with AFM, XPS, UPS and RAIRS studies. Periodic sub-micron electrode arrays can be created using micro-contact printing and electropolymerization. The sinusoidal modulation of the refractive index of such confined conducting polymer nanostructures or nanoparticle stripes allows efficient visible light diffraction. The modulation of the diffraction efficiency at PANI and PEDOT gratings in the presence of an analytical stimulus demonstrate the sensing capability at these surfaces.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 902 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Solid liquid Electrochemical Interfaces written by Gregory Jerkiewicz and published by . This book was released on 1997 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wide scope covered by the 23 papers makes the collection suitable as a survey of current developments in the subject, for specialists in electrochemical surface science, newcomers to the field, or scientists working in related disciplines. The topics include computer simulation of the structure and dynamics of water near metal surfaces, the growth kinetics of phosphate films on metal oxide surfaces, anion adsorption and charge transfer on single-crystal electrodes, an electrochemical and in-situ scanning-probe microscopic study of electroactive polymers, and the temperature dependence of the growth of surface oxide films on rhodium electrodes. Annotation copyrighted by Book News, Inc., Portland, OR.
Download or read book CHARACTERIZATION OF CHARGE INJECTION PROCESSES OF THIN FILMS ON INDIUM TIN OXIDE ELECTRODES USING A NOVEL SPECTROELECTROCHEMICAL TECHNIQUE POTENTIAL MODULATED ATTENUATED TOTAL REFLECTANCE SPECTROSCOPY written by Zeynep Araci and published by . This book was released on 2010 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding interfacial charge injection processes is one of the key factors needed for development of efficient organic electronic devices, such as biosensors and energy conversion systems, since these processes control the electrical characteristics of these devices. Spectroelectrochemical characterization of electron transfer processes occurring at the electrode - electroactive thin film interface has been evaluated to improve our understanding of charge transfer kinetics using a novel form of electroreflectance spectroscopy, potential-modulated attenuated total reflectance (PM-ATR), which makes it possible to sensitively monitor spectroscopic changes in thin films as a function of applied potential. PM-ATR was used to evaluate three different redox-active films deposited on indium tin oxide (ITO) electrodes to investigate: i) the orientation dependence of charge transfer rates of thin films of biomolecules, ii) surface treatment and modification effects on charge transfer kinetics of conducting polymers and, iii) estimation of rates of electron injection and conduction band edge of semiconductor nanocrystalline materials. First, Prussian blue film as a model system was used successfully to examine the PM-ATR technique for determination of the charge transfer rate constant between ITO and a molecular film. Second, an anisotropic and redox active protein film, cytochrome c, was used to probe charge transfer rates with respect to molecular orientation. The electron transfer rate measured using TM polarized light was four-fold greater than that measured using TE polarized light. These data are the first to correlate a distribution of molecular orientations with a distribution of electron transfer rates in a redox-active molecular film. Third, the effects of ITO surface treatment and modification on charge transfer kinetics on a conducting polymer, poly(3,4-ethylenedioxythiophene/)/poly(styrenesulfonate) (PEDOT/PSS), were studied. The apparent interfacial charge transfer rate constant for PEDOT/PSS on ITO has been reported for the first time which cannot be measured otherwise with conventional electrochemistry due to high non-Faradaic background of PEDOT/PSS films. Fourth, PM-ATR enabled characterization of reversible redox processes between submonolayer coverages of surface-tethered, CdSe nanocrystals and ITO for the first time. Optically determined onset potentials for electron injection were used for estimation for the conduction band and valance band energies (ECB and EVB, respectively).
Download or read book Chemically Modified Metal Oxide Nanostructures Electrodes for Sensing and Energy Conversion written by Sami Elhag and published by Linköping University Electronic Press. This book was released on 2017-02-02 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this thesis is the development of scalable, low cost synthesis of metal oxide nanostructures based electrodes and to correlate the chemical modifications with their energy conversion performance. Methods in energy conversion in this thesis have focused on two aspects; a potentiometric chemical sensor was used to determine the analytical concentration of some components of the analyte solution such as dopamine, glucose and glutamate molecules. The second aspect is to fabricate a photo-electrochemical (PEC) cell. The biocompatibility, excellent electro-catalytic activities and fast electron transfer kinetics accompanied with a high surface area to volume ratio; are properties of some metal oxide nanostructures that of a potential for their use in energy conversion. Furthermore, metal oxide nanostructures based electrode can effectively be improved by the physical or a chemical modification of electrode surface. Among these metal oxide nanostructures are cobalt oxide (Co3O4), zinc oxide (ZnO), and bismuth-zincvanadate (BiZn2VO6) have all been studied in this thesis. Metal oxide nanostructures based electrodes are fabricated on gold-coated glass substrate by low temperature (< 100 0C) wet chemicalapproach. X-ray diffraction, x-ray photoelectron spectroscopy and scanning electron microscopy were used to characterize the electrodes while ultraviolet-visible absorption and photoluminescence were used to investigate the optical properties of the nanostructures. The resultant modified electrodes were tested for their performance as chemical sensors and for their efficiency in PEC activities. Efficient chemically modified electrodes were demonstrated through doping with organic additives like anionic, nonionic or cationic surfactants. The organic additives are showing a crucial role in the growth process of metal oxide nanocrystals and hence can beused to control the morphology. These organic additives act also as impurities that would significantly change the conductivity of the electrodes. However, no organic compounds dependence was observed to modify the crystallographic structure. The findings in this thesis indicate the importance of the use of controlled nanostructures morphology for developing efficient functional materials.
Download or read book Handbook of Electrochemistry written by Cynthia G. Zoski and published by Elsevier. This book was released on 2007-02-07 with total page 935 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemistry plays a key role in a broad range of research and applied areas including the exploration of new inorganic and organic compounds, biochemical and biological systems, corrosion, energy applications involving fuel cells and solar cells, and nanoscale investigations. The Handbook of Electrochemistry serves as a source of electrochemical information, providing details of experimental considerations, representative calculations, and illustrations of the possibilities available in electrochemical experimentation. The book is divided into five parts: Fundamentals, Laboratory Practical, Techniques, Applications, and Data. The first section covers the fundamentals of electrochemistry which are essential for everyone working in the field, presenting an overview of electrochemical conventions, terminology, fundamental equations, and electrochemical cells, experiments, literature, textbooks, and specialized books. Part 2 focuses on the different laboratory aspects of electrochemistry which is followed by a review of the various electrochemical techniques ranging from classical experiments to scanning electrochemical microscopy, electrogenerated chemiluminesence and spectroelectrochemistry. Applications of electrochemistry include electrode kinetic determinations, unique aspects of metal deposition, and electrochemistry in small places and at novel interfaces and these are detailed in Part 4. The remaining three chapters provide useful electrochemical data and information involving electrode potentials, diffusion coefficients, and methods used in measuring liquid junction potentials. * serves as a source of electrochemical information * includes useful electrochemical data and information involving electrode potentials, diffusion coefficients, and methods used in measuring liquid junction potentials * reviews electrochemical techniques (incl. scanning electrochemical microscopy, electrogenerated chemiluminesence and spectroelectrochemistry)
Download or read book Ultrathin Metal Transparent Electrodes for the Optoelectronics Industry written by Dhriti Sundar Ghosh and published by Springer Science & Business Media. This book was released on 2013-05-13 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transparent electrodes (TEs) are a class of materials that make it possible to bring electrical current or potentials in close proximity to optically active regions without significant loss of optical energy. However, it is a challenge to decouple the electrical and optical properties of a material, as the property of conductivity is strongly coupled to the imaginary part of the refractive index. An ideal TE has high transparency in combination with very low electrical resistivity. The main objective of the thesis was to develop TEs which can replace expensive, scarce and fragile Indium Tin Oxide (ITO), the most widely used TE material in the industry today. The thesis contains original work on ultrathin metal film (UTMF)-based TEs, which are essential elements in a wide range of optoelectronics, consumer electronics and energy devices. It presents new designs and fabrication methods and demonstrates the efficient use of UTMF-TEs in organic light emitting diodes and solar cells, achieving similar levels of efficiency to that of state-of-the-art ITO.
Download or read book Electrochemistry of Carbon Electrodes written by Richard C. Alkire and published by John Wiley & Sons. This book was released on 2015-11-23 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book sets the standard on carbon materials for electrode design. For the first time, the leading experts in this field summarize the preparation techniques and specific characteristics together with established and potential applications of the different types of carbon-based electrodes. An introductory chapter on the properties of carbon together with chapters on the electrochemical characteristics and properties of the different modifications of carbon such as carbon nanotubes, graphene, carbon fiber, diamond or highly ordered pyrolytic graphite provide the reader with the basics on this fascinating and ubiquitous electrode material. Cutting-edge technologies such as carbon electrodes in efficient supercapacitors, Li-ion batteries and fuel cells, or electrodes prepared by screen-printing are discussed, giving a complete but concise overview about the topic. The clearly structured book helps newcomers to grasp easily the principles of carbon-based electrodes, while researchers in fundamental and applied electrochemistry will find new ideas for further research on related key technologies.
Download or read book Transparent Carbon Electrodes for Spectroelectrochemical Studies written by Erin Kate Walker and published by . This book was released on 2012 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes the assessment and use of carbon optically transparent electrodes (C-OTEs) based on pyrolyzed photoresist films (PPFs) as a platform for spectroelectrochemical investigations. C-OTEs are examined for use in UV-Vis spectroelectrochemistry and electrogenerated chemiluminescence and compared to non-transparent glassy carbon (GC) and the conventional transparent electrode indium tin oxide (ITO). Chapter 1 provides a general overview of transparent electrodes, carbon electrodes, and spectroelectrochemistry. Chapter 2 details a UV-Vis spectroelectrochemical investigation of electrogenerated graphitic oxides (EGO) on the surface of the C-OTE in the presence of KCl. X-ray photoelectron spectroscopy and time of flight secondary ion mass spectroscopy are used to determine EGO composition. Several supporting electrolytes are investigated to determine the mechanism of EGO formation. Chapter 3 details experiments to electrochemically access the exciton emission from self-assembled double-walled tubular J-aggregates via electrogenerated chemiluminescence (ECL). Optimization of ECL intensity with respect to the coreactant concentration and the supporting electrolyte pH is performed on opaque glassy carbon electrodes. ECL and fluorescence spectra are compared, and C-OTEs are utilized to determine the source of disagreement between the spectra. Chapter 4 describes the preparation and characterization (i.e. transparency, thickness, sheet resistance, rms roughness, and electroactive surface area) of C-OTEs and explores C-OTEs for general use in ECL under a variety of conditions. Simultaneous cyclic voltammograms and ECL transients are obtained for three thicknesses of PPFs and compared to non-transparent GC and the conventional transparent electrode ITO in both front face and transmission electrode cell geometries. Despite positive potential shifts in oxidation and ECL peaks, attributed to the internal resistance of the PPFs that result from their nanoscale thickness, the PPFs display similar ECL activity to GC, including the low oxidation potential observed for amine coreactants on hydrophobic electrodes. Overall, C-OTEs are promising electrodes for spectroelectrochemical applications because they yield higher ECL than ITO in both oxidative-reductive and reductive-oxidative ECL modes, are more stable in alkaline solutions, display a wide potential window of stability, and have tunable transparency for more efficient detection of light in the transmission cell geometry. Future directions for this research are discussed in Chapter 5, which outlines several approaches to designing and improving spectroelectrochemical sensors.
Download or read book Electronic and Structural Characterizations of a Transparent Conductive Oxide organic Interface written by Quentin Arnoux and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The energy level alignment of hole-transport organic molecular solids with indium tin oxide (ITO), a transparent conducting oxide, has been characterized. The studied molecules, based on the dipyranylidene (DIP) structure, differ by the heteroatom (O, S and Se). Synchrotron photoemission electron spectroscopy has been used to determine the alignment, and we investigated the molecular orientation via X-ray absorption spectromicroscopy. By interpreting spectroscopic data in the light of DFT calculations, we found evidence of the presence of charge transfer from the molecules to the ITO, when they are in intimate contact with the substrate, at least for the O and S-DIPs. The hole injection barrier between the ITO Fermi level and the organic HOMO was obtained. Our experimental approach emphasizes the relationship between structural and electronic properties. These results were obtained during beamtimes in France (SOLEIL), Italy (ELETTRA) and Switzerland (SLS).
Download or read book Semiconducting Polymers written by Georges Hadziioannou and published by John Wiley & Sons. This book was released on 2006-12-15 with total page 786 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of semiconducting polymers has attracted many researchers from a diversity of disciplines. Printed circuitry, flexible electronics and displays are already migrating from laboratory successes to commercial applications, but even now fundamental knowledge is deficient concerning some of the basic phenomena that so markedly influence a device's usefulness and competitiveness. This two-volume handbook describes the various approaches to doped and undoped semiconducting polymers taken with the aim to provide vital understanding of how to control the properties of these fascinating organic materials. Prominent researchers from the fields of synthetic chemistry, physical chemistry, engineering, computational chemistry, theoretical physics, and applied physics cover all aspects from compounds to devices. Since the first edition was published in 2000, significant findings and successes have been achieved in the field, and especially handheld electronic gadgets have become billion-dollar markets that promise a fertile application ground for flexible, lighter and disposable alternatives to classic silicon circuitry. The second edition brings readers up-to-date on cutting edge research in this field.
Download or read book Label Free Biosensing written by Michael J. Schöning and published by Springer. This book was released on 2018-07-20 with total page 485 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume summarizes the state-of-the-art technologies, key advances and future trends in the field of label-free biosensing. It provides detailed insights into the different types of solid-state, label-free biosensors, their underlying transducer principles, advanced materials utilized, device-fabrication techniques and various applications. The book offers graduate students, academic researchers, and industry professionals a comprehensive source of information on all facets of label-free biosensing and the future trends in this flourishing field. Highlights of the subjects covered include label-free biosensing with: · semiconductor field-effect devices such as nanomaterial-modified capacitive electrolyte-insulator-semiconductor structures, silicon nanowire transistors, III-nitride semiconductor devices and light-addressable potentiometric sensors · impedimetric biosensors using planar and 3D electrodes · nanocavity and solid-state nanopore devices · carbon nanotube and graphene/graphene oxide biosensors · electrochemical biosensors using molecularly imprinted polymers · biomimetic sensors based on acoustic signal transduction · enzyme logic systems and digital biosensors based on the biocomputing concept · heat-transfer as a novel transducer principle · ultrasensitive surface plasmon resonance biosensors · magnetic biosensors and magnetic imaging devices
Download or read book Wearable Bioelectronics written by Anthony P.F. Turner and published by Elsevier. This book was released on 2019-11-26 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wearable Bioelectronics presents the latest on physical and (bio)chemical sensing for wearable electronics. It covers the miniaturization of bioelectrodes and high-throughput biosensing platforms while also presenting a systemic approach for the development of electrochemical biosensors and bioelectronics for biomedical applications. The book addresses the fundamentals, materials, processes and devices for wearable bioelectronics, showcasing key applications, including device fabrication, manufacturing, and healthcare applications. Topics covered include self-powering wearable bioelectronics, electrochemical transducers, textile-based biosensors, epidermal electronics and other exciting applications. - Includes comprehensive and systematic coverage of the most exciting and promising bioelectronics, processes for their fabrication, and their applications in healthcare - Reviews innovative applications, such as self-powering wearable bioelectronics, electrochemical transducers, textile-based biosensors and electronic skin - Examines and discusses the future of wearable bioelectronics - Addresses the wearable electronics market as a development of the healthcare industry
Download or read book Spectroelectrochemistry written by Wolfgang Kaim and published by Royal Society of Chemistry. This book was released on 2008 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical guidebook illustrating the applications of spectroelectrochemistry to the understanding of redox reactions through identification of their intermediaries and products.
Download or read book Immobilized Biocatalysts written by Peter Grunwald and published by MDPI. This book was released on 2018-11-14 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Immobilized Biocatalysts" that was published in Catalysts
Download or read book Conducting Polymers written by György Inzelt and published by Springer Science & Business Media. This book was released on 2008-04-08 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a systematic survey of the knowledge accumulated in this field in the last thirty years. It includes material on the thermodynamic aspects of the polymers, the theory of the mechanism of charge transport processes, and the chemical and physical properties of these compounds. Also covered are the techniques of characterization, the electrochemical methods of synthesis, and the application of these systems. Inzelt’s book is a must-read for electrochemists and others.
Download or read book Glucose Sensing written by Chris D. Geddes and published by Springer Science & Business Media. This book was released on 2007-12-29 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt: An essential reference for any laboratory working in the analytical fluorescence glucose sensing field. The increasing importance of these techniques is typified in one emerging area by developing non-invasive and continuous approaches for physiological glucose monitoring. This volume incorporates analytical fluorescence-based glucose sensing reviews, specialized enough to be attractive to professional researchers, yet appealing to a wider audience of scientists in related disciplines of fluorescence.
