Highly crystalline anatase TiO 2 nanocuboids as an efficient photocatalyst for hydrogen generation.

Highly crystalline anatase titanium dioxide (TiO 2 ) nanocuboids were synthesized via a hydrothermal method using ethylenediamine tetraacetic acid as a capping agent. The structural study revealed the nanocrystalline nature of anatase TiO 2 nanocuboids. Morphological study indicates the formation of cuboid shaped particles with thickness of ∼5 nm and size in the range of 10-40 nm. The UV-visible absorbance spectra of TiO 2 nanocuboids showed a broad absorption with a tail in the visible-light region which is attributed to the incorporation of nitrogen atoms into the interstitial positions of the TiO 2 lattice as well as the formation of carbonaceous and carbonate species on the surface of TiO 2 nanocuboids. The specific surface areas of prepared TiO 2 nanocuboids were found to be in the range of 85.7-122.9 m 2 g -1 . The formation mechanism of the TiO 2 nanocuboids has also been investigated. Furthermore, the photocatalytic activities of the as-prepared TiO 2 nanocuboids were evaluated for H 2 generation via water splitting under UV-vis light irradiation and compared with the commercial anatase TiO 2 . TiO 2 nanocuboids obtained at 200 °C after 48 h exhibited higher photocatalytic activity (3866.44 μmol h -1 g -1 ) than that of commercial anatase TiO 2 (831.30 μmol h -1 g -1 ). The enhanced photoactivity of TiO 2 nanocuboids may be due to the high specific surface area, good crystallinity, extended light absorption in the visible region and efficient charge separation.