Figure 3

(a–b) The surface and (c–d) inner chemical compositions of the nanoporous Cu/Cu2O/Cu dented cubic composites formed after 30 min reduction.
(a) SEM image and (b) line-scan EDS profile of the surface of a typical nanoporous Cu/Cu2O/Cu dented cubic composites. (c) FIB-FESEM cross section image of the same sample, showing the inner nanoporous structure. (d) Cu/O ratio of the three areas marked in (c) as determined by area-scan EDS. The scale bars represent 1 um.