Metal Ion–Induced Synthesis of Hierarchical ZnO Architectures with Various Morphologies and Their Photocatalytic Performances

Abstract

Three-dimensional (3D) hierarchical ZnO nanostructures were synthesized on zinc-electroplated Cu foil in one kind of metal salt-ammonia hydrothermal system. The morphologies, structures, components and spectra of the as-prepared products were characterized with SEM, XRD, EDS and UV-vis-DRS. The results showed the morphology of hierarchical ZnO architectures changed with varying the kind of metal salts added in the hydrothermal system, while the hexagonal wurtzite structure of ZnO kept constant. The photocatalytic experiment showed that different hierarchical ZnO films showed different photocatalytic activities for degrading methyl orange aqueous solution under ultraviolet irradiation, which was attributed to the difference of specific surface area, porous channel properties and light scattering effect from different hierarchical ZnO architectures. The inherent characteristics of metal ions, involving ionic radius, solubility and crystal structure of its oxide or hydroxide precipitates, and so on, was speculated to play an important role in the change of morphology of hierarchical ZnO architectures.