Fabrication and optical properties of ordered sea urchin-like ZnO nanostructures by a simple hydrothermal process

Ordered sea urchin-like zinc oxide (ZnO) nanostructures were fabricated via a simple hydrothermal process at relatively mild conditions by one step. The microstructure, morphology and the photoelectric properties of the as-prepared products were investigated by x-ray diffraction, transmission electron microscopy, field emission environment scanning electron microscopy, UV–visible optical absorption and photocurrent–voltage measurements. The results demonstrated that the ZnO crystals had hexagonal wurtzite structures, and were assembled by a central nucleus and many needle-like ZnO which grew radially from the nucleus. Compared with ZnO nanorod arrays, the sea urchin-like ZnO nanostructures showed preferable photoelectric properties as the anode of dye-sensitized solar cells. This can be attributed to special geometric morphologies.