Figure 1

Field emission scanning electron microscopy top, magnified and cross-sectional images of (a–c) ZnO NRs, (d–f) Si MPs and (g–i) ZnO/Si HRs with a 100-μm micropost spacing, and (j–l) ZnO/Si HRs with a 50-μm micropost spacing. The inset images in a, d, g and j show the static water contact angles of PTFE-coated ZnO NRs, Si MPs and ZnO/Si HRs with a 100-μm micropost spacing, and ZnO/Si HRs with a 50-μm micropost spacing, respectively.