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A combined X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) methodology is here presented on a series of partially and fully reduced Au(III) samples. This allows monitoring the relative fraction of Au(III) and Au(0) in the studied samples, displaying a consistent and independent outcome. The strategy followed is based, for the first time, on two structural models that can be fitted simultaneously, and it evaluates the correlation among strongly correlated parameters such as coordination number and the Debye-Waller factor. The results of the present EXAFS and XANES approach can be extended to studies based on X-ray absorption spectroscopy experiments for the in situ monitoring of the formation of gold nanoclusters.

Vanadium pentoxide materials prepared through sol-gel processes act as excellent intercalation hosts for lithium as well as polyvalent cations. A chemometric approach has been applied to study the X-ray absorption near-edge structure (XANES) evolution during in situ scanning of the Cu(0.1)V(2)O(5) xerogel/Li ions battery. Among the more common techniques, the fixed size windows evolving factor analysis (FSWEFA) permits the number of species involved in the experiment to be determined and the range of existence of each of them. This result, combined with the constraints of the invariance of the total concentration and non-negativity of both concentrations and spectra, enabled us to obtain the spectra of the pure components using a multivariate curve resolution refined by an alternate least squares fitting procedure. This allowed the normalized concentration profile to be understood. This data treatment evidenced the occurrence, for the first time, of three species during the battery charging. This fact finds confirmation by comparison of the pure spectra with the experimental ones. Extended X-ray absorption fine structure (EXAFS) analysis confirms the occurrence of three different chemical environments of Cu during battery charging.