Understanding the growth mechanism of titanium disilicide nanonets.

The titanium disicilicate (TiSi(2)) nanonet is a material with a unique two-dimensional morphology and has proven beneficial for energy conversion and storage applications. Detailed knowledge about how the nanonet grows may have important implications for understanding seedless nanostructure synthesis, in general, but is presently missing. Here, we report our recent efforts toward correcting this deficiency. We show that the TiSi(2) nanonet growth is sensitive to the nature of the receiving substrates. High-yield nanonets are only obtained on those exhibiting no or low reactivities with Si. This result indicates that Si-containing clusters deposited on the substrate surfaces play an important role in the nanonet synthesis, and we suggest they serve to initiate the growth. The morphological complexity of the nanonet depends on the precursor concentrations but not on the growth durations. More TiCl(4) results in nanonets with more complex structures. We understand that once a beam of a TiSi(2) nanonet is formed, its sidewalls are resistant to branch formation. Instead, the tip of a beam is where a branch forms. This process is driven by the reactions between Ti- and Si-containing species. Building on this understanding, we demonstrate the creation of second-generation nanonets.