328565.fig.003a
(a)
328565.fig.003b
(b)
328565.fig.003c
(c)
328565.fig.003d
(d)
Figure 3: C1s XPS spectra of GO (a) and RGO-Au (b). The black solid lines are original spectra; the dash line, dot line and dash, and dot line are assigned to sp2-C, C–O (hydroxyl and epoxy groups), C=O (carboxyl groups), respectively. Au4f XPS spectra for the GO- A u C l 4 and RGO-Au nanocomposites: (c) GO- A u C l 4 and (d) RGO-Au.