Fabrication and growth mechanism of metal (Zn, Sn) nanotube arrays and metal (Cu, Ag) nanotube/nanowire junction arrays

We report the successful synthesis of metal (Zn, Sn) nanotube arrays and metal (Cu, Ag) nanotube/nanowire junction arrays electrochemically deposited through nanoporous anodic alumina membranes. The metal (Zn, Sn) nanotube arrays were achieved by preferentially plating at circular step edges of the Au nanorings with hydrogen gas generation, critical to the evolution of tube formation. Quite interestingly, if there is no hydrogen gas generation, the metal (Cu, Ag) nanotube/nanowire junction arrays were obtained. This approach is very simple, molecular anchor free, and is generally capable of growing other metal nanotube arrays and nanotube/nanowire junction arrays.