Template-free electrochemical synthesis of Cd/CdTe core/shell nanowires and CdTe nanotubes

Template-free electrodeposition is a facile, low-cost and environmentally friendly method for the synthesis of one-dimensional (1D) nanostructures. In this study, the template-free electrodeposition was successfully utilized to synthesize 1D nanostructures of CdTe nanotubes and Cd/CdTe core/shell nanowires. In an alkaline electrolyte containing Cd and Te sources, Cd/CdTe core/shell nanowires and CdTe nanotubes were directly electrodeposited on ITO-coated glass substrates under a stationary cathodic potential. The Cd cores of the nanowires are single crystalline with a cubic structure and preferential growth along the direction, while the CdTe shells of the nanowires and the CdTe nanotubes are polycrystalline. It is proposed that Cd nanowires were first formed along the direction due to the anisotropic crystal growth of Cd. Then, the Cd nanowires were electrochemically converted into CdTe, and Cd/CdTe core/shell nanowires and CdTe nanotubes were formed based on the Kirkendall effect.