Facile Coengineering of Oxygen Defects and Highly Active {110} Facets in TiO2 Nanorods for Efficient Water Splitting

Optimizing the photocatalytic activity of TiO2 for hydrogen evolution from water splitting remains a challenging task. Herein, we report the synthesis of a slightly oxygen-deficient TiO2 film consisting of anatase nanorods with mainly {110} lateral surfaces by a facile one-step technology of magnetron sputtering. The 1D nanostructure and Ti3+/oxygen vacancies in the as-prepared TiO2 film are advantageous for the inhibition of recombination of electron-hole pairs, while the exposed {110} lateral surfaces provide abundant surface active sites; as a result, this TiO2 exhibited an ultrahigh photocatalytic activity for water splitting. Remarkably, photocatalytic overall water splitting into H-2 and O-2 simultaneously with a ratio close to 2:1 has been realized for the first time over pristine anatase TiO2 without the assistance of sacrificial electron donor and cocatalyst. Additionally, in the presence of methanol as a sacrificial agent, the pristine TiO2 displayed a high apparent quantum efficiency of similar to 21.4% at 365 nm and the hydrogen generation rate under the full-arc light irradiation could be as high as 14.35 mmol m(-2) h(-1), which is about 3 orders of magnitude higher than that of P25 film (similar to 0.014 mmol m(-2) h(-1)). This result provides a facile pathway to synthesizing defect-based metal oxide with optimal facets and morphology for high-efficiency energy conversion.