Transformation of metal nanowires into metal nanotubes by a sequential thermal process

The simple, low-cost and scalable transformation of metallic nanowires into metallic nanotubes was demonstrated by employing sequential thermal treatments (i.e. thermal oxidation followed by thermal reduction). Using this approach, the grain size, diameter, morphology and wall thickness of the metal nanotubes were easily adjusted by varying the oxidation or reduction temperatures, time and repetitive sequential thermal processes.