Fig. 2 demonstrates the morphology and structure characterization
results of ZnO and Cu2O before and after combination. As
shown in Fig. 2a, ZnO produced in this condition is some rod-like
nanostructures. From Fig. 2b, as-prepared pure Cu2O is some
particles in nanoscale and submicroscale. The morphology and
structure of ZnO/Cu2O CSNCs determined by SEM and TEM are
shown in Fig. 2c and d, where it can be seen that numerous nanoparticles
uniformly distribute and form a shell/coating of Cu2O
on the surface of ZnO nanorods. The above suggests that the
combination of ZnO and Cu2O form a typical ZnO/Cu2O core-shell
structure. Additionally, compared with the pure Cu2O powder, the
Cu2O from ZnO/Cu2O CSNCs obviously showed smaller size. It is
probably attributed to the introduction of ZnO nanorods into Cu2O
synthesis solution which make the nucleation and precipitate of
Cu2O become easy.