Spectroelectrochemistry, the future of visualizing electrode processes by hyphenating electrochemistry with spectroscopic techniques

Abstract

The combination of electrochemistry and spectroscopy, known as spectroelectrochemistry (SEC), is an already established approach. By combining these two techniques, the relevance of the data obtained is greater than what it would be when using them independently. A number of review papers have been published on this subject, mostly written for experts in the field and focused on recent advances. In this review, written for both the novice in the field and the more experienced reader, the focus is not on the past but on the future. The scope is narrowed down to four techniques the authors claim to have the most potential for the future, namely: infrared spectroelectrochemistry (IR-SEC), Raman spectroelectrochemistry (Raman-SEC), nuclear magnetic resonance spectroelectrochemistry (NMR-SEC) and, perhaps slightly more controversial but certainly promising, electrochemistry mass-spectrometry (EC-MS).

Characterizing photocatalysts for water splitting: from atoms to bulk and from slow to ultrafast processes

“…In situ or even operando characterization for HER and OER in photocatalysis settings is far less applied than, e.g., for electrocatalysts, where numerous review articles give an overview on characterization techniques applied, e.g., UV/vis, FT-IR, Raman, XAFS, ambient pressure XPS (AP-XPS), EPR, etc. 52,[98][99][100][101][102][103][104][105][106][107] One challenge of the analysis of photocatalysts under operating conditions is the additional illumination, which needs to be integrated properly into the experimental setups to ensure that the illuminated volume and the probed volume of the sample are overlapping. Another issue is that the illumination may also interfere with some of the applied optical techniques.…”

“…Spectroelectrochemistry (SEC) comprises the combination of various spectroscopic techniques with electrochemical methods. 99,107,159 In the context of catalysis, SEC has mainly been reported to monitor electrode processes and study mechanisms in electrocatalysis. 107,[160][161][162][163][164] In the context of electrocatalysis SEC experiments come close to operando conditions while for light-driven catalysis, electrochemical generation can be used to simulate photochemical generation of catalytic active species or short-lived intermediates in electron transfer chains.…”

“…99,107,159 In the context of catalysis, SEC has mainly been reported to monitor electrode processes and study mechanisms in electrocatalysis. 107,[160][161][162][163][164] In the context of electrocatalysis SEC experiments come close to operando conditions while for light-driven catalysis, electrochemical generation can be used to simulate photochemical generation of catalytic active species or short-lived intermediates in electron transfer chains. 101,104,162,165 As discussed above, in the context of the mechanistic investigation of the multi-electron transfer cascades involved in HER or OER, the identification and spectroscopic characterization of intermediates plays a critical role.…”

TowardsoperandoIR‐ and UV‐vis‐Spectro‐Electrochemistry: A Comprehensive Matrix Factorisation Study on Sensitive and Transient Molybdenum and Tungsten Mono‐Dithiolene Complexes**

“…Electrochemical experiments represent highly sophisticated methods for studying redox processes and chemical transformations involving redox events. In recent decades, setups that couple electrochemistry with spectroscopic methods (spectroelectrochemistry [30][31][32][33] ) ranging from IR [34,35] and UV-vis [36][37][38] to EPR [39] and fluorescence [40] spectroscopies have gained substantial interest due to the breadth of chemical information they can attain. Spectro-electrochemical setups can provide structural and electronic information on steady state and intermittent species, however the desired spectroscopic information is usually encoded in the matrices acquired during the measurements.…”

Large-area fabrication of Au nanoantennas for surface enhanced infrared spectroscopy without an adhesion layer

“…SEIRAS, first observed by Hartstein et al 6 in the 1980's and further pioneered by the group of Osawa in the 1990's 7,8 , is a technique often compared with surface enhanced Raman spectroscopy (SERS), although there are some distinct differences. These differences are most notable when comparing the enhancement factors of the two techniques, for SERS [9][10][11] , enhancement factors of up to 10 10 have been achieved, while reported SEIRAS enhancement factors 12,13 are more modest, in the range of 10 1-5 . SEIRAS substrates can be roughly categorized in two different groups, namely substrates consisting of roughened metallic films, or so called resonantly tuned nanoantennas.…”