Heterojunction of FeTiO₃ Nanodisc and TiO₂ Nanoparticle for a Novel Visible Light Photocatalyst

For the first time, a single crystalline FeTiO 3 nanodisc in the ilmenite phase has been synthesized by a hydrothermal reaction at 220 °C. The prepared FeTiO 3 was a hexagonal disk-like structure with an average diameter of ∼400 nm and a thickness of ∼70 nm, while its hexagonal face was oriented in (001) plane and grown to (110) direction. The heterojunction structure was formed between the as-prepared FeTiO 3 nanodisc and Degussa P25 with an average particle size of ∼25 nm by employing maleic acid as an organic linker. The prepared FeTiO 3 /TiO 2 coupled at a nanoscale demonstrated greatly enhanced photocatalytic activity in removing 2-propanol and evolving CO 2 in gas phase under visible light irradiation (λ ≥ 420 nm). Its degradation constant ( k ) in removing 2-propanol was ∼25 times that of Degussa P25, which suggests that its catalytic efficiency is comparable to that of a typical N-doped TiO 2 . The remarkable photocatalytic activity of FeTiO 3 /TiO 2 could be explained by the intersemiconductor hole-transfer mechanism caused by the unique relative band positions of these two semiconductors.