Figure 4

SEM images of the as-synthesized 3D mesoporous metal oxide networks.
(a) WO3, (b) Fe2O3, (c) Co3O4, (d) NiO, (e) CuO and (f) CeO2.

SEM images of the as-synthesized 3D mesoporous metal oxide networks.
(a) WO3, (b) Fe2O3, (c) Co3O4, (d) NiO, (e) CuO and (f) CeO2.