Electrodeposition of Y2O3-Au composite coatings for SOFC interconnects: in situ monitoring of film growth by surface enhanced Raman spectroscopy

In this paper, the authors report in situ surface enhanced Raman spectroscopy (SERS) experiments carried out during the electrochemical deposition of Y2O3/Au from chloride salts dissolved in hydroalcoholic solutions containing chitosan as a binder. This composite was recently proposed by the authors as an electronically conducting coating able to protect AISI 430 interconnects from hot corrosion in SOFC cathodic environment. Dynamic SERS spectra were obtained during galvanostatic electrodeposition, showing peaks in the typical Raman shift range of M-O stretching and bending vibrations that have been tentatively assigned on the basis of quantum-chemical computations. The time dependence of the spectral features can be followed with a simple kinetic model accounting for the pH transient occurring in the catholyte.