Figure 3

XPS spectra of energetic Ag-doped CNTs at different doses; a C1 s peaks of as-grown CNTs and the CNTs doped at 3 × 10¹⁶ cm⁻², inset is XPS spectrum of CNTs doped at 3 × 10¹⁶ cm⁻²; in which element Ag has been doped into CNTs successively, and the positions of C1 s peaks do not change after Ag ion implantation; b Ag 3d5 peaks of CNTs doped at different doses, which demonstrates that the chemical structures of element Ag doped into CNTs are metal Ag instead of C–Ag compound