Atomic layer deposition of titanium dioxide nanostructures using carbon nanosheets as a template

Nanostructured films of anatase TiO2 is deposited on carbon nanosheet (CNS) templates using atomic layer deposition (ALD). The high-surface area of the CNS together with the unique step coverage of the ALD process makes it possible to obtain sheet-like TiO2 nanostructures, for use in potential applications, e.g. photocatalysis and photovoltaics. A problem with ALD on CNS was the low nucleation rate giving TiO2 films with pinholes. It is shown that introduction of defects by an acid-treatment process can be used to control initial nucleation and growth of the films. The TiO2 on the defect-rich CNS nucleates faster and results in a film with no observable pinholes consisting of crystalline grains in an amorphous matrix.