Electronic Structure of Silver Oxides Investigated by AgL XANES Spectroscopy

The chemistry of binary and multinary silver oxides spans from subvalent species (with a mean oxidation number for Ag smaller than + 1) to compounds with Ag in high oxidation states as + 2 and + 3. We have investigated a range of silver oxides, including the binary compounds Ag2O, AgO, Ag3O4 and Ag2O3 as well as subvalent ternary oxides, by AgL3 and AgL1 XANES spectroscopy. The different valence states of silver are clearly reflected in AgL3 and AgL1 XANES spectra. The method thus allows the determination of average oxidation numbers. In addition, the degree of electronic interaction (localized or delocalized electronic states) in silver-oxygen compounds can be estimated on the basis of AgL3 XANES spectra