Figure 2. Full-scale images of (a) unmodified Cu/C and (d) modified Cu/C; SEM images of the surfaces of (b) unmodified biomorphic Cu/C and (e) modified biomorphic Cu/C; and (c) and (f) enlarged images of (b) and (e), respectively; (g) EDS spectra of the surfaces of biomorphic carbon, unmodified Cu/C, and modified Cu/C.