Double-sided ZnO nanorod arrays on single-crystal Ag holed microdisks with enhanced photocataltytic efficiency

Novel hierarchical heterostructures of double-sided ZnO nanorod (NR) arrays grown on single-crystal Ag holed microdisks (HMDs) have been prepared through a two-step aqueous strategy including ZnO seed loading and the subsequent heteroepitaxial growth of ZnO NRs on Ag HMDs. By simply adjusting the synthetic parameters, ZnO NRs with variable NR diameters (20-200 nm), lengths (100-1.8 mu m) and unusual shapes (concave, tubular and sharp tips) on Ag HMDs have been realized, which endows the Ag/ZnO heterostructures with versatile morphologies. The novel Ag/ZnO heterostructures consisting of integrated 1D semiconductor/2D metal nanostructured blocks with high specific surface area (SSA) and opened spatial architectures may promise important applications related to photoelectric fields. As expected, in photocatalytic measurements, the typical Ag HMD/ZnO NR heterostructure exhibits superior catalytic activity over other catalysts of bare ZnO NRs, ZnO NR arrays or heterostructured Ag nanowires (NWs)/ZnO NRs. The synergistic effect of the unique Ag HMD/ZnO NR heterostructures contributing to the high catalytic performance has been discussed in detail.