91207 - Molecular Electrochemistry

Learning outcomes

At the end of the course the student has acquired the theoretical and experimental basis for the comprehension and investigation of the physical-chemical processes associated to electron transfer processes, either heterogeneous or homogeneous and intramolecular.

Course contents

Lectures (module 1)

1. Introduction to the course. Measurability of potentials; inner and outer potentials. Volta effect. The electrode potential and Nernst equation.
   
2. The structure and properties of the electrified interphases. Differential capacity of the electrode/solution interphase. Models of the electrochemical interphase: Helmholtz model, Gouy-Chapman-Stern model. Adsorption.
3. The rate of the heterogeneous electron transfer (ET) process. Anodic and cathodic processes. The Butler-Volmer equation: standard rate constant and coefficient of the heterogeneous ET. The kinetic overpotential. Inner sphere processes: the HER and OER. Volcano plots, Tafel plots and the Potential Determining Step concept (thermodynamic overpotential).
4. Marcus' model of the homogeneous and heterogeneous (outer sphere) ET: the solvent reorganization energy. Non-adiabatic ET: heterogeneneous and intramolecular ET. Photoinduced ET.
5. Mass transport in solution. Fick's Law and resolution of the diffusion equation in some cases of electroanalytical interest. Methods for mass transport control: forced convection and spherical diffusion (ultramicroelectrodes). Potentiodynamic transient techniques: cyclic voltammetry and electrochemical impedance spectroscopy.
6. Wrap-up: the (Randles') equivalent circuit

Practical Lab and seminars (module 2)

Simulation of cyclic voltammetric experiments; simple experiments aimed to showing some of the most important electrochemical techniques: cyclic voltammetry and chronoamperometry; ultramicroelectrodes; electrochemiluminescence; electrochemical impedance spectroscopy.

Readings/Bibliography

Lecture notes distributed by the teacher are available on Virtuale.

Allen J. Bard, Larry R. Faulkner, Henry S White Electrochemical Methods. Fundamentals and Applications, Wiley, New York, 2022 (third edition)

Teaching methods

Taught classes and seminars. Lab experiences.

As concerns the teaching methods of this course unit, all students must attend Module 1, 2 [https://www.unibo.it/en/services-and-opportunities/health-and-assistance/health-and-safety/online-course-on-health-and-safety-in-study-and-internship-areas] on Health and Safety, online.

Assessment methods

The evaluation is based on 2 alternative type of exam (at choice of the student):

1) a written exam with three questions/problems to verify thegeneral knowledge of the program

or

2) oral exam where the candidate presents (normally at the blackboard) a subject of his/her own choice which will then be briefly discussed with the examiners. Additional questions concerning other parts of the program will be asked

The final grade is the results of the evaluation of the overall performance of the candidate in either type of exam.

Teaching tools

Blackboard, Power Point slides, simple experiments in lab.

Office hours

See the website of Francesco Paolucci

See the website of Giovanni Valenti