DOCSLIB.ORG

Lecture #1 Introducton to Electrochemistry

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Lecture #1 Introducton to Electrochemistry Lecture #1 Introduc.on to electrochemistry Kaori Sugihara Email: [email protected] HP: h@p://www.unige.ch/sciences/chifi/sugiharalab/ Lecture plan § Lecture 1: Introduc.on to electrochemistry § Lecture 2: Thermodynamics of electrochemical cells § Lecture 3: Impedance spectroscopy § Lecture 4: Cyclic voltammetry § Lecture 5: Electrophore.c techniques + Electrophysiology § Lecture 6: Other state of art applicaons in electrochemistry Exam: A wri@en exam for 2 h (the date to be fixed later) You are allowed to bring the printouts and a calculator. Reference: Electrochemical methods – fundamentals and applicaons Allen J. Bard Larry R. Faulkner Program of today´s class Goal of the lecture § To understand what kinds of applicaons electrochemistry has § To understand the characteris.cs of ideal polarized electrodes § To understand two-, three-, and four-electrode measurement setup Electrochemistry Baeries Fuel cells Corrosion Electroplang of metals Protein purificaon (Electrophoresis) History of electrochemistry Luigi Galvani, Italy (1737-1798) Electrolysis of water William Nicholson, English (1753-1815) Johann Wilhelm Ri@er, Germany (1776-1810) The first baery Alessandro Volta, Italy (1745-1827) The first mass produced baery William Cruickshank, Scotland (-1811) Biosensors Diabetes Glucose sensor The leading cause for death in the world Normal range 4.4 – 6.6 mM Dreams.me.com How does it work? biocataly.c reac.on Flavin adenine Glucose oxidase (GOx) dinucleode (FAD) electrode J. Wang, Chem. Rev. 2008, 108, 814-825 Dye-sensi.zed solar cell New generaon solar panel § Higher efficiency? § Lower cost? A. Hagfeldt, et al., Chem. Rev. 2010, 110, 6595–6663 How does it work? ( fluorine-doped n oxide) A. Hagfeldt, et al., Chem. Rev. 2010, 110, 6595–6663 Nobel prize in electrochemistry Wilhelm Ostwald Jaroslav Heyrovský Arne Wilhelm Kaurin Tiselius Latvia (1853-1932) Check republic (1890-1967) Sweden (1902-1971) Nobel Prize in Chemistry Nobel Prize in Chemistry Nobel Prize in Chemistry in 1909 in 1959 in 1948 Catalysis, chemical Polarography (mercury electrophoresis equilibria, reac.on electrode) velocies What will happen when we put an electrode under aqueous solu.on? Pt, Ag etc. Ideal polarized electrode + V No charge transfer (electrons do not move from solu.on to the metal) q H+ + E OH- OH- H+ Electrical double layer Stern layer hp://en.wikipedia.org/wiki/File:EDLC-Poten.aldistribu.on.png Charging currents for a constant voltage V Charging currents for a constant voltage Solve this equaon for q(t)… E constant! In case of constant current Solve this equaon for E(t)… i constant! In case of linear voltage sweep Solve this equaon for i(t)… E(t), i(t) So far we learned ideal polarized electrodes. However, most of the .me, real electrodes are NOT ideal polarized electrodes! Non-polarized electrodes V e- There is charge transfer A + e- à B e- - C à D + e + H R C E OH- H+ - OH Lecture 3: Impedance spectroscopy Electrode reac.on rate V e- There is charge transfer A + e- à B e- C à D + e- Per unit .me H+ - OH Per unit area H+ OH- polarized electrodes vs non-polarized electrodes Pt Au AgCl Number of the electrodes This part is extremely important! This will be one of the ques.ons in the exam!! Two electrode measurements What is the resistance of this sample RS? I V A … Is this really RS? à NO! Two electrode measurements Contact resistance RS (resistance at the interface) r r I V A Four electrode measurements VS V Contact resistance RS (resistance at the interface) r r I Do not use this value! V A What if you are interested in one of the contact resistance r? RS r r I V A Three electrode measurements VS V RS r r I V A In electrochemistry I V A R1 R2 RSoluon C1 C2 V R = = R + R + R I Solution 1 2 If you are interested only in one interface I V A VS Reference electrode V R1 R2 RSoluon C1 C2 Working electrode Counter electrode (the electrode of interest) V R = S = R + R I Solution 1 The standard three electrode setup in electrochemistry Three electrode cell Poten.ostat Poten.ostat Counter electrode Pt V 1 Reference electrode AgCl I A V V2 Au V Working electrode R = 2 I Which technique do you have to use? Two, three or four electrode set up? We want to study the effect of polymer coang on an gold electrode. soluon polymer Au electrode K. Sugihara, et al., The Journal of Physical Chemistry B, 2010, 114, 13982-13987. We want to study the polymer resistance. soluon polymer Chip (insulator) with a pore K. Sugihara, et al., The Journal of Physical Chemistry B, 2010, 114, 13982-13987. We want to study the ac.vi.es of ion channels. S. Demarche, et al., Analyst, 2011, 136. Alternave tricks to perform “4 electrode measurements” with 2 electrodes I V A R1 R2 RSoluon C1 C2 V R = = R + R + R I Solution 1 2 Alternave tricks to perform “4 electrode measurements” with 2 electrodes I V A R1 R2 RSoluon C1 C2 V R = = R + R + R I Solution 1 2 Ag/AgCl electrode (≠ AgCl electrode) AgCl wire (solid) KCl + AgCl soluon (Cl-, Ag+) Porous plug (salt bridge) AgCl (s) + e- à Ag (s) + Cl- (aq) Very small charge transfer resistance and capacitance à Perfect non-polarized electrode Galvanic vs Electroly.c Take home messages • Electrochemistry is technologically very important for baeries, solar cells, biosensors etc. • Ideal polarized electrodes and non-polarized electrodes have different characteris.cs (real electrodes are most of the .me in between). • It is extremely important to select the right configuraon (2, 3 or 4 electrode setup) for electrochemical measurements. Today’s references § Allen J. Bard, Larry R. Faulkner, Electrochemical methods – fundamentals and applicaons § J. Wang, Chem. Rev. 2008, 108, 814-825 § A. Hagfeldt, et al., Chem. Rev. 2010, 110, 6595–6663 .
Load more

Recommended publications
  • Materials Science
    Materials Science Materials Science is an interdisciplinary field combining physics (fundamental laws of nature), chemistry (interactions of atoms) and biology (how life interacts with materials) to elucidate the inherent properties of basic and complex systems. This includes optical (interaction with light), electrical (interaction with charge), magnetic and structural properties of everyday electronics, clothing and architecture. The Materials Science central dogma follows the sequence: Structure—Properties—Design—Performance. This involves relating the nanostructure of a material to its macroscale physical and chemical properties. By understanding and then changing the structure, material scientists can create custom materials with unique properties. The goal of the materials science minor is to create a cross-disciplinary approach to fundamental topics in basic and applied physical sciences. Students will gain experience and perspectives from the disciplines of chemistry, physics and biology. The minor places a strong emphasis on current nanoscale research methods in addition to the basics of electronic, optical and mechanical properties of materials. Any student with an interest in pursuing the cross-disciplinary minor in materials science should consult with the coordinator of the minor. Students are encouraged to declare their participation in their sophomore year but no later than the end of the junior year. Students also should seek an adviser from participating faculty. Degree Requirements for the Minor General College requirements
    [Show full text]
  • 2. Electrochemistry
    EP&M. Chemistry. Physical chemistry. Electrochemistry. 2. Electrochemistry. A phenomenon of electric current in solid conductors (class I conductors) is a flow of electrons caused by the electric field applied. For this reason, such conductors are also known as electronic conductors (metals and some forms of conducting non-metals, e.g., graphite). The same phenomenon in liquid conductors (class II conductors) is a flow of ions caused by the electric field applied. For this reason, such conductors are also known as ionic conductors (solutions of dissociated species and molten salts, known also as electrolytes). The question arises, what is the phenomenon causing the current flow across a boundary between the two types of conductors (known as an interface), i.e., when the circuit looks as in Fig.1. DC source Fig. 1. A schematic diagram of an electric circuit consis- flow of electrons ting of both electronic and ionic conductors. The phenomenon occuring at the interface must involve both the electrons and ions to ensure the continuity of the circuit. metal metal flow of ions ions containing solution When a conventional redox reaction occurs in a solution, the charge transfer (electron transfer) happens when the two reacting species get in touch with each other. For example: Ce4+ + Fe 2+→ Ce 3+ + Fe 3+ (2.1) In this reaction cerium (IV) draws an electron from iron (II) that leads to formation of cerium (III) and iron (III) ions. Cerium (IV), having a strong affinity for electrons, and therefore tending to extract them from other species, is called an oxidizing agent or an oxidant.
    [Show full text]
  • Physical Chemistry MEHAU KULYK / SCIENCE PHOTO LIBRARY LIBRARY PHOTO SCIENCE / KULYK MEHAU
    Physical chemistry MEHAU KULYK / SCIENCE PHOTO LIBRARY LIBRARY PHOTO SCIENCE / KULYK MEHAU 44 | Chemistry World | August 2010 www.chemistryworld.org Let’s get physical Physical chemists are finding themselves more in demand than ever. Emma Davies finds out why Physical chemistry is entering theory in harmony, he said: ‘with the called Fueling the future, his team something of a golden era. Its overall perspective of contributing In short is using IR spectroscopy to see tools have advanced dramatically accurate, experimentally vetted, The field of physical how protons are accommodated in recent years, so much so that molecular level pictures of reactive chemistry is booming, as in imidazole nanostructures. The scientists from all disciplines are pathways and relevant structures, more and more scientists project is based at the University of entering collaborations with physical physical chemists are in an excellent seek to understand their Massachussetts at Amhurst, US and chemists to gain new insight into position to engage chemistry in work on a molecular level teams are currently working on fuel their specialist subject areas. There is all of its complexity.’ He believes Developing alternative cells containing alternatives to nafion, however some worry that the subject that understanding processes at a energy sources is one a fluoropolymer-copolymer which is could become a victim of its own molecular level is crucial to making area benefiting from a good proton conductor but fails in success, with fundamental research grand scientific leaps forward. a physical chemistry meeting contemporary demand for losing out in the funding stakes to Johnson and his team are working approach high temperature operation.
    [Show full text]
  • Syllabus Chem 646
    SYLLABUS CHEM 646 Course title and number Physical Organic Chemistry, CHEM 646 Term Fall 2019 Meeting times and location MWF 10:20 am – 11:10 am, Room: CHEM 2121 Course Description and Learning Outcomes Prerequisites: Organic Chemistry I and II or equivalent undergraduate organic chemistry courses. Physical Organic Chemistry (CHEM646) is a graduate/senior-undergrad level course of advanced organic chemistry. Physical organic chemistry refers to a discipline of organic chemistry that focuses on the relationship between chemical structure and property/reactivity, in particular, applying experimental and theoretical tools of physical chemistry to the study of organic molecules and reactions. Specific focal points of study include the bonding and molecular orbital theory of organic molecules, stability of organic species, transition states, and reaction intermediates, rates of organic reactions, and non-covalent aspects of solvation and intermolecular interactions. CHEM646 is designed to prepare students for graduate research on broadly defined organic chemistry. This course will provide the students with theoretical and practical frameworks to understand how organic structures impact the properties of organic molecules and the mechanism for organic reactions. By the end of this course, students should be able to: 1. Gain in-depth understanding of the nature of covalent bonds and non-covalent interactions 2. Use molecule orbital theory to interpret the property and reactivity of organic species. 3. Understand the correlation between the structure and physical/chemical properties of organic molecules, such as stability, acidity, and solubility. 4. Predict the reactivity of organic molecules using thermodynamic and kinetic analyses 5. Probe the mechanism of organic reactions using theoretical and experimental approaches.
    [Show full text]
  • Atoms and Molecules
    230 NATURE [Nov~1rnER 6, 1919 electricity. In the model atom proposed by Sir of Sommerfeld, Epstein, and others. The general­ J. J. Thomson the electrons were supposed to be ised theory has proved very fruitful in accounting embedded in a sphere of positive electricity of in a formal way for many of the finer details of about the dimension of the atom as ordinarily spectra, notably the doubling of the lines in the understood. Experiments on the scattering hydrogen spectrum and the explanation of the of a-particles through large angles as the complex details of the Stark and Zeeman effects. result of a single collisioh with a heavy In these theories of Bohr and his followers it is atom showed that this type of atom was not cap­ assumed that the electrons are in periodic orbital able of accounting for the facts unless the positive motion round the nucleus, and that radiation only sphere was much concentrated. This led to the arises when the orbit of the electron is disturbed nucleus atom of Rutherford, where the positive in a certain way. Recently Langmuir, from a charge and also the mass of the atom are supposed consideration of the general physical and chemical to be concentrated on a nucleus of minute dimen­ properties of the elements, has devised types of sions. The nucleus is surrounded at a distance by atom in which the electrons are more or less fixed a distribution of negative electrons to make it in position relatively to the nucleus like the atoms electrically neutral. The distribution of the ex­ of matter in a crystal.
    [Show full text]
  • Syllabus (Fall 2019) Chemistry 562: Physical Chemistry II
    Syllabus (Fall 2019) Chemistry 562: Physical Chemistry II The policies and regulations contained in this syllabus are subject to change at any point. Such changes will be announced in class and/or posted on the course website. The syllabus has been compiled to be as complete as possible but is by no means a binding document. General Info Instructor: Prof. Jörg C. Woehl Office: Chemistry Building (CHM), Room 343 Office hours: Open door Email: [email protected] Phone: 414-229-5223 Class Meeting Times: Monday, Wednesday, and Friday, 9:00-9:50 am Class Location: CHM 197 Discussion Group: Friday, 1:00-1:50 pm in CHM 193 Teaching Assistant: Quintus Owen ([email protected]) TA Office hours: Wednesday, 1:00-2:00 pm in CHM 218 First Day of Class: Wednesday, September 4 Last Day of Class: Wednesday, December 11 Midterm 1 (in-class): Monday, October 14, 9:00-9:50 am Midterm 2 (take-home): Monday, November 11; due following Monday at 9:00 am Final Exam: Monday, December 16, 10:00-12:00 noon (CHM 197) Course Objectives This lecture course covers quantum mechanics (as it applies to the chemical sciences), chemical kinetics, and statistical mechanics (thermodynamics). In contrast to “Physical Chemistry I” (Chem-561), the approach we take in this course is purely microscopic. Starting with electrons and nuclei, we will arrive at a quantum-mechanical description of the atom, and use the same approach to understand chemical bonding, reactions, and thermodynamic properties. Individual Particles Quantum mechanics is used to describe the motion of microscopic particles, and we will introduce the concepts using the historical evolution of quantum theory.
    [Show full text]
  • Physical Chemistry I
    Physical Chemistry I Andrew Rosen August 19, 2013 Contents 1 Thermodynamics 5 1.1 Thermodynamic Systems and Properties . .5 1.1.1 Systems vs. Surroundings . .5 1.1.2 Types of Walls . .5 1.1.3 Equilibrium . .5 1.1.4 Thermodynamic Properties . .5 1.2 Temperature . .6 1.3 The Mole . .6 1.4 Ideal Gases . .6 1.4.1 Boyle’s and Charles’ Laws . .6 1.4.2 Ideal Gas Equation . .7 1.5 Equations of State . .7 2 The First Law of Thermodynamics 7 2.1 Classical Mechanics . .7 2.2 P-V Work . .8 2.3 Heat and The First Law of Thermodynamics . .8 2.4 Enthalpy and Heat Capacity . .9 2.5 The Joule and Joule-Thomson Experiments . .9 2.6 The Perfect Gas . 10 2.7 How to Find Pressure-Volume Work . 10 2.7.1 Non-Ideal Gas (Van der Waals Gas) . 10 2.7.2 Ideal Gas . 10 2.7.3 Reversible Adiabatic Process in a Perfect Gas . 11 2.8 Summary of Calculating First Law Quantities . 11 2.8.1 Constant Pressure (Isobaric) Heating . 11 2.8.2 Constant Volume (Isochoric) Heating . 11 2.8.3 Reversible Isothermal Process in a Perfect Gas . 12 2.8.4 Reversible Adiabatic Process in a Perfect Gas . 12 2.8.5 Adiabatic Expansion of a Perfect Gas into a Vacuum . 12 2.8.6 Reversible Phase Change at Constant T and P ...................... 12 2.9 Molecular Modes of Energy Storage . 12 2.9.1 Degrees of Freedom . 12 1 2.9.2 Classical Mechanics .
    [Show full text]
  • States of Origin: Influences on Research Into the Origins of Life
    COPYRIGHT AND USE OF THIS THESIS This thesis must be used in accordance with the provisions of the Copyright Act 1968. Reproduction of material protected by copyright may be an infringement of copyright and copyright owners may be entitled to take legal action against persons who infringe their copyright. Section 51 (2) of the Copyright Act permits an authorized officer of a university library or archives to provide a copy (by communication or otherwise) of an unpublished thesis kept in the library or archives, to a person who satisfies the authorized officer that he or she requires the reproduction for the purposes of research or study. The Copyright Act grants the creator of a work a number of moral rights, specifically the right of attribution, the right against false attribution and the right of integrity. You may infringe the author’s moral rights if you: - fail to acknowledge the author of this thesis if you quote sections from the work - attribute this thesis to another author - subject this thesis to derogatory treatment which may prejudice the author’s reputation For further information contact the University’s Director of Copyright Services sydney.edu.au/copyright Influences on Research into the Origins of Life. Idan Ben-Barak Unit for the History and Philosophy of Science Faculty of Science The University of Sydney A thesis submitted to the University of Sydney as fulfilment of the requirements for the degree of Doctor of Philosophy 2014 Declaration I hereby declare that this submission is my own work and that, to the best of my knowledge and belief, it contains no material previously published or written by another person, nor material which to a substantial extent has been accepted for the award of any other degree or diploma of a University or other institute of higher learning.
    [Show full text]
  • A Short History of Chemistry J.R.Partington January 22-29, 2017
    A Short History of Chemistry J.R.Partington January 22-29, 2017 What are the major discoveries in Chemistry, who are the mayor players? When it comes to (classical) music, ten composers cover most of it that deserves to be part of the indispensable culture, when it comes to painting let us say a hundred might be necessary, and as to literature, maybe a thousand. What about mathematics, physics and chemistry? Here the situation may be thought of as more complicated as many minor workers, if not individually at least collectively, have contributed significantly to the discipline, and this might be particularly the case with chemistry, which more than mathematics and physics depends on tedious work carried out by armies of anonymous toilers in laboratories. But Chemistry is not just routine work but as any science depends on daring hypotheses and flights of fancy to be confronted with an unforgiving empirical reality. Who are the Gausses and Eulers of Chemistry, to say nothing of a Newton. Is there in analogy with Bell’s ’Men of Mathematics’ a corresponding compilation of chemical heroes? In one sense there is, names such as Scheele, Priestley. Pasteure, may be more well-known to the general public than Gauss, Euler or Lagrange. On the other hand a mathematician taking part of the cavalcade is invariably a bit disappointed, none of the names mentioned and lauded, seem to have the same luster as the kings of mathematics, instead diligence and conscientious steadfast work seems to carry the day. In one way it is unfair, in spite of mathematics supposedly being the least accessible of all the sciences, literally it is the opposite, being entirely cerebral.
    [Show full text]
  • Introduction to Catalysis
    1 1 Introduction to Catalysis Ask the average person in the street what a catalyst is, and he or she will probably tell you that a catalyst is what one has under the car to clean up the exhaust. Indeed, the automotive exhaust converter represents a very successful application of cataly- sis; it does a great job in removing most of the pollutants from the exhaust leaving the engines of cars. However, catalysis has a much wider scope of application than abating pollution. Catalysis in Industry Catalysts are the workhorses of chemical transformations in the industry. Approximately 85–90 % of the products of chemical industry are made in cata- lytic processes. Catalysts are indispensable in . Production of transportation fuels in one of the approximately 440 oil refi- neries all over the world. Production of bulk and fine chemicals in all branches of chemical industry. Prevention of pollution by avoiding formation of waste (unwanted byproducts). Abatement of pollution in end-of-pipe solutions (automotive and industrial exhaust). A catalyst offers an alternative, energetically favorable mechanism to the non- catalytic reaction, thus enabling processes to be carried out under industrially feasible conditions of pressure and temperature. For example, living matter relies on enzymes, which are the most specific cata- lysts one can think of. Also, the chemical industry cannot exist without catalysis, which is an indispensable tool in the production of bulk chemicals, fine chemicals and fuels. For scientists and engineers catalysis is a tremendously challenging, highly multi- disciplinary field. Let us first see what catalysis is, and then why it is so important for mankind.
    [Show full text]
  • Physical Chemistry Thermodynamics and Kinetics Rates Reaction
    Thermodynamics and kinetics Thermodynamics Physical Chemistry Observe relative stability of states Energy differences Static comparisons of states Lecture 4 Kinetics Introduction to chemical kinetics Observe changes of state over time Several different topics Empirical description of the rate of reaction Determination of experimental parameters Microscopic theories Rates Reaction velocity A chemical reaction is described by an The rates of appearance of products and equation of the type disappearance of reactants are related by 1 stoichiometry of the reaction H() gas O () gas H O ( liquid ) 2222 Define the reaction velocity, v, in terms of Rates: “normalized” rates of appearance of products and disappearance of reactants Rate of change of [H2O]: d[H2O]/dt Rate of change of [H ]: d[H ]/dt 1 di[] 2 2 v Rate of change of [O ]: d[O ]/dt 2 2 i dt Rates related by the overall equation Example of the production of water: 1 oxygen molecule disappears for every 2 dH[]dO []dHO [ ] hydrogen molecules in the above reaction v 222 2 dt dt dt Rate laws Order Describe of how reaction velocity depends on In many situations, one may write the functional parameters such as concentrations, form of the reaction velocity approximately as vkABC [][][]abc temperature, pressure, etc. a, b, c are the orders of reaction under the vfABTP ([react ],[ prod ], , ) conditions examined May be simple or complex Many reaction velocities are more complicated functions than the simple one above Gives insight into the manner in which the Example: Production
    [Show full text]
  • Ucla Chemistry-Materials Science Organic Concentration 2012-2013
    UCLA CHEMISTRY-MATERIALS SCIENCE ORGANIC CONCENTRATION 2012-2013 CHEMISTRY-MATERIALS SCIENCE MAJOR (B.S.), ORGANIC CONCENTRATION: This concentration is designed primarily for students who are interested in chemistry with an emphasis on the material properties of organic matter. The major provides appropriate preparation for graduate studies in fields emphasizing interdisciplinary research involving chemistry, engineering, and applied science. Refer to the UCLA General Catalog (www.registrar.ucla.edu/catalog) for course descriptions and requisites. For more details about this major and others offered in the Department of Chemistry and Biochemistry, consult the Undergraduate Office in 4006 Young Hall. Preparation for the Major General Chemistry (Chem) 20A(H), 20B(H), 20L, 30AL Organic Chemistry (Chem) 30A(H), 30B, 30BL, 30C, 30CL Math 31A, 31B, 32A, 32B, 33B Physics 1A(H), 1B(H), 1C(H), 4BL (H) indicates that an HONORS section is available Upper Division Major Requirements Chemistry (Chem) 110A, 113A, 136, 171, C185 One Chemistry Elective 110B, C113B, C143A, C143B, 144, C172, C174, C175, C176, C180, C181 (4 units) Materials Science & 104, 110, 110L, 120, 150 Engineering One Materials Science & Engineering Elective 111, 121, 122, 131, 132, 160, 162, CM180 (4 units) Laboratory Electives Chem 114, 118, 184; Materials Science & Engineering 121L, 131L, 161L (7 units) Important Notes You may not take or repeat a chemistry or biochemistry course for credit if it is a prerequisite for a more advanced course for which you already have credit. Seminars, individual study courses, and research courses (e.g. 196, 199) may not be used to satisfy the requirements for the Chemistry Materials Science Organic Concentration major.
    [Show full text]