Preparation of a novel Cd₂Ta₂O₇ photocatalyst and its photocatalytic activity in water splitting

Cd₂Ta₂O₇, which showed high photocatalytic activity for overall water splitting, was synthesized by sol-gel method. Its maximum activity increased from 46.2 μmol-H₂/h and 23.0 μmol-O₂/h into 173.0 μmol-H₂/h and 86.3 μmol-O₂/h when 0.2 wt.% NiO was loaded as co-catalyst. The band structure of Cd₂Ta₂O₇ was calculated by a plane-wave-based density functional theory (DFT). The valence band is mainly formed by O 2p AO's, and the conduction band predominantly consists of Ta 5d, O 2p and Cd 5s5p AO's. Cd atoms endue new features different from other tantalates, and its effect on the band structure of Cd₂Ta ₂O₇ was discussed.