Spectroelectrochemical Studies of Redox Reactions and Electrified Interfaces at Nanostructured Carbon Electrodes in RTILs
Abstract
Room temperature ionic liquids (RTILs) are a unique class of materials that have found use in a variety of practical applications including energy storage devices, fuel cells and separations. Despite their increasing use, many fundamental issues remain in terms of understanding dynamics, organization and the response of these liquid electrolytes to external stimuli. Electrochemical and spectroelectrochemical research is being conducted to understand how the microstructure and surface chemistry of nanostructured carbon electrodes (conducting diamond and tetrahedral amorphous carbon) affect heterogeneous electron-transfer kinetics, electrode capacitance and molecular adsorption as a function of the RTIL type and viscosity. Heterogeneous electron-transfer rate constants, activation energies for electron-transfer, reorganization energies and the formal potentials of redox probe molecules are being determined in different RTILs. The redox probe molecules include ferrocene and ferrocene carboxaldehyde (neutral), ferrocene carboxylic acid (anion) and (ferrocenylmethyl)trimethylammonium iodide (cation). Studies are being performed using chemically-modified thin films functionalized by RF plasma (H2, O2, Ar and NH3 groups) and the electrochemically-assisted reduction of diazonium salts (para-substituted phenyl moieties covalently bonded to the surface). The research is producing new knowledge about the structure of electrified interfaces and electrochemical reactions in RTILs at these relatively new carbon electrode materials. The focus on fundamental interfacial electron-transfer, electrode surface chemistry/surface films and mass transport in these novel media are aligned with the ARO mission in Electrochemistry/Chemical Sciences. New knowledge about surface chemistry effects on electron transfer in RTILs, RTIL organization with distance from the electrode as a function of potential, and RTIL compositional effects on electron transfer is being produced. Knowledge and practices gained from the projectÕs interdisciplinary research agenda are giving the students the tools needed to be successful electrochemists and material scientists. Students are developing sound critical thinking and presentation skills, and learning how to productively interact (teamwork) with colleagues in a laboratory setting. Professional development activities (e.g., Individual Development Plan) are giving the students (graduate, undergraduate and high school) confidence and making them more competitive for employment, graduate school or undergraduate studies in STEM. High school and undergraduate student participants are experiencing graduate level research and training at a formative point in their careers, enhancing their desire to enter graduate school and ultimately become professional scientists. Finally, the students are experiencing the benefits of positive mentoring, understanding the importance of proper mentoring, and learning ways that they can serve as mentors.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 20, 2019
- Source ID
- W911NF1910174
Entities
People
- Greg Swain
Organizations
- Army Contracting Command
- Michigan State University
- United States Army