Callaghan Innovation Research Papers

Back to Research Papers

TitleA combined SNIFTIRS and XANES study of electrically polarized copper electrodes in DMSO and DMF solutions of cyanate (NCO-), thiocyanate (NCS-) and selenocyanate (NCSe-) ions
Publication TypeJournal Article
Year of Publication2015
AuthorsAlwis, L.K.H.K., Mucalo M.R., Ingham B., and Kappen P.
JournalJournal of the Electrochemical Society
PaginationH434 - H448
Date Published2015
ISSN00134651 (ISSN)
KeywordsCopper, Copper compounds, Dimethyl sulfoxide, Dimethyl sulfoxide (DMSO), Electrochemical experiments, Electrodes, Fourier transform infrared, Fourier transform infrared spectroscopy, Inorganic compounds, Ions, Organic solvents, Polar aprotic solvent, Polarization, Polarization experiments, Pseudohalide complexes, Tetrabutylammonium perchlorates, X ray absorption spectroscopy, X-ray absorption near edge spectroscopy
AbstractA SNIFTIRS (subtractively normalized interfacial Fourier transform infrared spectroscopy) and X-ray absorption spectroscopy (XAS) study of electrically polarized copper electrodes in six polar aprotic solvent-based systems is presented. In the systems investigated, i.e. dimethyl formamide (DMF) and dimethyl sulfoxide (DMSO) solutions containing pseudohalide species of cyanate (NCO-), thiocyanate (NCS-) and selenocyanate (NCSe-) codissolved with tetrabutylammonium perchlorate (TBAP), Cu was found to dissolve over a wide range of potentials to produce the corresponding Cu(I) pseudohalide and/or Cu(II) pseudohalide complex ion species. Insoluble deposited films were also observed at higher anodic applied potentials, thought to be CuSCN in the Cu/NCS-/DMSO or DMF systems, and solid K(SeCN)3 in the Cu/NCSe-/DMSO or DMF systems respectively. The presence of the Cu(II) and/or Cu(I) oxidation states in complexes formed by polarization in Cu/pseudohalide ion systems in DMSO was clearly proven using XAS of cell solutions sampled after SNIFTIRS/electrical polarization experiments. In addition, Fourier transform infrared (FTIR) and X-ray absorption near edge spectroscopy (XANES) data obtained from model solutions prepared from mixing Cu(I) and/or Cu(II) salts with the respective pseudohalide ions in DMF and DMSO confirmed the speciation observed in the electrochemical experiments. © 2015 The Electrochemical Society.

Back to top