Atomic layer deposition-based synthesis of photoactive TiO2 nanoparticle chains by using carbon nanotubes as sacrificial templates

Abstract

Highly ordered and self supported anatase TiO₂ nanoparticle chains were fabricated by calcining conformally TiO₂ coated multi-walled carbon nanotubes (MWCNTs). During annealing, the thin tubular TiO₂ coating that was deposited onto the MWCNTs by atomic layer deposition (ALD) was transformed into chains of TiO₂ nanoparticles (∼12 nm diameter) with an ultrahigh surface area (137 cm² per cm² of substrate), while at the same time the carbon from the MWCNTs was removed. Photocatalytic tests on the degradation of acetaldehyde proved that these forests of TiO₂ nanoparticle chains are highly photoactive under UV light because of their well crystallized anatase phase.