Highly crystalline anatase TiO2nanocuboids as an efficient photocatalyst for hydrogen generation

Abstract

Highly crystalline anatase titanium dioxide (TiO2) nanocuboids were synthesizedviaa hydrothermal method using ethylenediamine tetraacetic acid as a capping agent. The structural study revealed the nanocrystalline nature of anatase TiO2nanocuboids. 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 TiO2nanocuboids 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 TiO2lattice as well as the formation of carbonaceous and carbonate species on the surface of TiO2nanocuboids. The specific surface areas of prepared TiO2nanocuboids were found to be in the range of 85.7-122.9 m2g−1. The formation mechanism of the TiO2nanocuboids has also been investigated. Furthermore, the photocatalytic activities of the as-prepared TiO2nanocuboids were evaluated for H2generationviawater splitting under UV-vis light irradiation and compared with the commercial anatase TiO2. TiO2nanocuboids obtained at 200 °C after 48 h exhibited higher photocatalytic activity (3866.44 μmol h−1g−1) than that of commercial anatase TiO2(831.30 μmol h−1g−1). The enhanced photoactivity of TiO2nanocuboids may be due to the high specific surface area, good crystallinity, extended light absorption in the visible region and efficient charge separation.