SEIRAS

Surface-Enhanced Infrared Absorption Spectroscopy

Hartstein et al. (DOI) reported that thin discontinuous films (∼10 nm thick) of gold or silver metal layers coated onto an ATR prism with the further addition of molecular layers resulted in appreciable signal enhancement. This approach has come to be known as surface-enhanced infrared absorption spectroscopy (SEIRAS). Osawa et al. (DOI) established the possibility of ATR-SEIRAS for in situ electrochemical studies by using a metal film deposited on a silicon ATR prism. The measured surface enhancement results primarily from the amplified local electric field due to the oscillating plasmonic electrons at the grain boundaries of the nanostructured film. The realisation of SEIRAS gave important new scope to in situ IR studies of electrochemical interfaces. A vital advantage offered by the intensification of the signal (enhancement factors up to 1,000) at the interface is that it enables monitoring of the surface reactions and structural dynamics at the interface, with considerably higher time resolution than previously obtained.

Within our research group we study the electrode-electrolyte interfaces using a cell configuration similar to Figure (a) relevant to Li-ion and metal-air battery systems (Figure (b)) and electrochemical capacitors.

 

Figure (a) Schematic of experimental setup for ATR-SEIRAS spectroelectrochemical cell, (b) Cyclic voltammetry, 10 mV/s scan rate, and corresponding in situ SEIRA spectra in O₂ saturated 0.1 M lithium triflate in dimethyl sulfoxide on a Au electrode, grey shadings show the region where potential dependent bands pertaining to LiO₂ or Li₂O₂ are observed.

Figure reproduced from Vivek J.P. et al. In Situ Surface-Enhanced Infrared Spectroscopy to Identify Oxygen Reduction Products in Nonaqueous Metal-Oxygen Batteries. J. Phys. Chem. C. 121 (2017) 19657 DOI.

 

Publications, review articles and book chapters on SEIRAS

Advanced spectroelectrochemical techniques to study electrode interfaces within lithium-ion and lithium-oxygen batteries 
A. J. Cowan and L. J. Hardwick
Annu. Rev. Anal. Chem., 12 (2019), 23.1- 23.24 DOI

Metal-Air Batteries: Fundamentals and Applications; Chapter 9 Metal-Air Battery: In Situ Spectro-electrochemical Techniques
I. M. Aldous, L. J. Hardwick, R. J. Nichols, and J. Padmanabhan Vivek Ed. Xin-Bo Zhang, Wiley 2018, Book

In Situ Surface-Enhanced Infrared Spectroscopy to Identify Oxygen Reduction Products in Nonaqueous Metal–Oxygen Batteries
J. Padmanabhan Vivek, N.G. Berry, J. Zou, R. J. Nichols, L. J. Hardwick
J. Phys. Chem. C, 121  (2017) 19657-19667 DOI

Mechanistic Insight into the Superoxide Induced Ring Opening in Propylene Carbonate Based Electrolytes using In Situ Surface-Enhanced Infrared Spectroscopy
Padmanabhan Vivek, N.G. Berry, G. Papageorgiou, R. J. Nichols, L. J. Hardwick
J. Amer. Chem. Soc., 138 (2016) 3745-3751 DOI