Figure 1

SEM images of Gra (a), Chi-Gra (b) and Cu(I)/Cu(II)-Chi-Gra (c). The zones examined by EDS (marked by red boxes) and the results of the analysis are also shown for the Gra (d), Chi-Gra (e) and Cu(I)/Cu(II)-Chi-Gra (f) samples.
SEM images of Gra (a), Chi-Gra (b) and Cu(I)/Cu(II)-Chi-Gra (c). The zones examined by EDS (marked by red boxes) and the results of the analysis are also shown for the Gra (d), Chi-Gra (e) and Cu(I)/Cu(II)-Chi-Gra (f) samples.