Visible Light Active Pure Rutile TiO₂ Photoanodes with 100% Exposed Pyramid-Shaped (111) Surfaces

A pure rutile TiO₂ photoanode with 100% exposed pyramid-shaped (111) surfaces has been directly synthesized on a fluorine-doped tin oxide (FTO) conducting substrate via a facile one-pot hydrothermal method. The resulting rutile TiO₂ film on the FTO substrate possessed a film thickness of ca. 5 μm and showed good mechanical stability. After calcination at 450 ℃ for 2 h in argon (Ar), the fabricated rutile TiO₂ films with 100% exposed pyramid-shaped (111) surfaces were used as photoanodes, exhibiting excellent visible light photoelectrocatalytic activity toward oxidation of water and organics. The excellent visible light activity of the pure rutile TiO₂ film photoanode can be attributed to the Ti³⁺ doping in the bulk and high reactivity of the {111} crystal facets. Such a pure rutile TiO₂ film with highly reactive (111) surfaces is a promising material for visible light photocatalysis and solar energy conversion.