Facile electrochemical synthesis of ZnO/PbSe heterostructure nanorod arrays and PbSe nanotube arrays

The ZnO/PbSe core-shell nanorod arrays were fabricated by a two-step electrodeposition method from aqueous solution for the first time. The synthesized core-shell nanorod arrays were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The obtained samples share the characters of both ZnO and PbSe in XRD patterns. The SEM images show that the average diameter and length of ZnO nanorods are 120–200 nm and 2.5 μm, respectively. The TEM images show that these heterostructured nanorods are made up of two parts, a single crystalline ZnO nanorod with a [0 0 1] growth direction as the core and crystalline PbSe layer as the shell. The absorption spectrum of ZnO/PbSe shows visible light absorption from 500 nm to 650 nm due to the PbSe coating. In addition, the PbSe nanotube arrays were fabricated by immersing the heterostructures in hydrochloric acid, which were characterized by SEM and TEM. SEM images show that the average diameter of these nanotubes is 250 nm and the average thickness of their walls is about 75 nm. TEM images show that the PbSe nanotubes exhibit polycrystalline structure.