General Layer-By-Layer Approach To Composite Nanotubes and Their Enhanced Lithium-Storage and Gas-Sensing Properties

A novel and versatile layer-by-layer approach has been developed to synthesize composite metal oxide nanotubes on carbon-nanotube (CNT) templates. We demonstrate this approach by the preparation of CeO2-SnO2 and Ag-NiO composite nanotubes. The electrostatic attraction between the CNTs and metal ions play the most Important role in the formation of CNT-based core-shell nanotubes, from which the composite metal oxide nanotubes are subsequently synthesized. It is found that the CeO2-SnO2 and Ag-NiO composite nanotubes lead to excellent device performance when they are used in gas sensors and Li-ion batteries, respectively.