SEM analysis on a cross-section of the Cu-foam sample supported
the fairly homogeneous distribution of captured Cr on the volume of
Cu foam at a mesoscale level (Fig. 8a). However, higher magnification
SEM images revealed that two different morphologies exist on the surface
of the Cu-foam cell walls: i) a rather rough morphology that presents
a number of protruding crystalline nodules interspersed with a
limited number of smooth areas (Fig. 8b), and ii) regions with smooth
appearance embedded in areas characterized mainly by porous and
cellular aspects (Fig. 8c). EDS analysis dictated that smooth areas were
almost pure copper, while the protruding crystalline nodules were
rich in Cr. It is noticeable that the pre-existing microporosity of the
initial Cu-foam pore walls is not discernible, presumably, due to the
coverage of the foam with treatment products.