Fig. 6. (a) Normalized XANES spectra of Au-L_III (top curves) and Ag–K edge (bottom curves) measured on reference foils (Au and Ag, black lines) and on AuNR samples (AuNR—HQ: blue and AuNR—AA: red). The reference spectra of Ag⁺ (AgNO₃ and AgCl) and Ag²⁺ (AgO) are shown for the sake of comparison (from ref. 39–41). (b) Moduli of the Fourier transforms |FT| of k^w weighted EXAFS spectra of Au-L_III (top curves) and Ag–K (bottom curves) edges for the reference foils (black lines) and AuNRs (AuNR-HQ: blue, AuNR-AA: red). (c) Results of the Au EXAFS data fitting for AuNR-HQ and AuNR-AA samples. The experimental (black dots), best fit (red lines) and the partial contributions used for the analysis (orange lines) are shown (vertically shifted for clarity). The bottom curves (purple dots) represent the residues (experimental data minus best fit). (d) Results of the Ag–K edge EXAFS fitting for AuNR-HQ and AuNR-AA samples. The black dots represent the experimental data, the red line the best fit, the orange ones represent the contribution of every path to the final fit and the purple dots represent the residual. All plots are shifted vertically for the sake of clarity. The larger noise on AuNR-AA forces restriction of the range for the analysis (see text).