Retrospective and Prospective Views of Electrochemical Electron Transfer Processes: Theory and Computations

Renat R. Nazmutdinov, Jens Ulstrup

Research output: Chapter in Book/Report/Conference proceedingBook chapterResearchpeer-review

Abstract

An electrochemical renaissance
Prompted by concepts and methodologies of solid state and surface physics, a new era of physical and theoretical electrochemistry, almost like an electrochemical renaissance, began in the 1970s, transforming electrochemistry into interdisciplinary, highly sophisticated condensed matter physical science [1–4]. Notions were “clean”, i.e. single-crystal, atomically planar electrochemical surfaces, and a range of surface spectroscopies including UV/Vis, infrared, Raman, surface enhanced Raman, and X-ray photoelectron spectroscopy.
From the same time statistical physics [5–7] and electronic structure theories [8–10] were introduced, with the palatable jellium or free electron gas model in initial focus [10]. Prior to the electrochemical renaissance the electrochemical surface was viewed as a hard wall with all physical events on the solution side. A jellium “tail” interfacing the electrolyte, exposed to surface charging and molecular “pseudopotentials”, could incorporate exciting features of metal dependent capacitance [8, 9], solvent structure [6–9, 11], adsorption [12], and effects such as surface plasmonics [13] and second harmonic generation [14]. Well-defined electrochemical microenvironments [15–17] paved the way for electrochemical scanning tunneling (STM) and atomic force microscopy (AFM) (in situ STM and AFM) [4, 17–20], with both surface and tip under electrochemical control. In situ STM/AFM brought electrochemical surface mapping to atomic and adsorbates to sub-molecular resolution [3, 20–23] by a subtle phenomenon, quantum mechanical tunneling [24, 25]. New approaches to electrochemical processes were opened, creating a new area suitably denoted as single-molecule electrochemistry.

A bioelectrochemical renaissance
Similar boundary-traversing efforts were introduced in interfacial electrochemistry of redox metalloproteins [4, 26, 27], DNA-based molecules [4, 28–30], and even whole protein and enzyme complexes [31]. It is in fact remarkable that molecules as large and fragile as metalloproteins can now be mapped to the single-molecule level directly in aqueous biological media. Single-molecule electrochemistry has prompted new concepts of interfacial electron transfer (ET) through complex molecules, relating both to the finite-size system nature (stochastic as opposed to statistical) [32] and to new single-molecule ET phenomena [23, 32–35]. Phenomenological theory offers powerful frames, but major computational efforts are now needed. For example, even the prettiest in situ STM images of the best organized self-assembled molecular monolayers (SAMs) reduce to “blobs”, unless backed up by large-scale electronic structure computations. Such computations convert the images to electronic conductivity through the molecular fragments, with amazing detail and sometimes surprises, never deciphered just by looking at the images (see section 2.5).
We start with a retrospective view on quantum electrochemical processes, including less-known elements of electrochemical ET theory. We then proceed to the new nanoscale and single-molecule electrochemistry. Along the way, and in our third part, we overview computational methods and their application to some electrochemical systems.
Original languageEnglish
Title of host publicationAtomic-Scale Modelling of Electrochemical Systems
EditorsMarko M. Melander, Tomi T. Laurila, Kari Laasonen
Number of pages65
PublisherWiley
Publication date2022
Pages27-91
Chapter2
ISBN (Print)9781119605614
ISBN (Electronic)9781119605652
DOIs
Publication statusPublished - 2022

Fingerprint

Dive into the research topics of 'Retrospective and Prospective Views of Electrochemical Electron Transfer Processes: Theory and Computations'. Together they form a unique fingerprint.

Cite this