A two-dimensional crystal growth in anatase titania nanostructures driven by trigonal hydronium ions.

Two-dimensional growth or high-energy faceting during a wet-chemical nanocrystal growth involves a dynamic surfactant functionalization that selectively allows a particular crystal plane to grow and simultaneously, passivates others from evolving. Here, by simply controlling the concentration of hydronium ions in a liquid-phase deposition reaction, the two-dimensional growth of a few atoms thick and (001) facet in anatase titania nanostructures can be achieved. The morphology can be modified from nanocube to nanobelt and nanosheet by increasing the hydronium ion concentration. Raman analysis reveals that the trigonal hydronium ions attach to the growing planes of anatase TiO a dative bonding, projecting atom-thick and large-scale (001) faceted nanobelts and nanosheets.