Wet-chemistry hydrogen doped TiO2 with switchable defects control for photocatalytic hydrogen evolution

Hydrogen has a remarkably flexible chemistry in oxides. We show that the introduction of H into simple TiO2 leads to greatly enhanced photocatalytic properties, and specifically yields a 60 times enhancement of photocatalytic hydrogen evolution activity over commercial rutile. The hydrogenated TiO2 (H-TiO2) is synthesized by a new one-step wet-chemistry approach yielding switchable defect via controlled annealing. As-prepared H-TiO2 has Ti-H bonds in the lattice from replacement of oxygen by hydrogen atoms. The Ti-H bonds are converted to oxygen vacancies by loss of H2O with Ar annealing. Oppositely, Ti-H defects are healed by Ti-O with O-2 annealing. The strongly enhanced photocatalytic activity is associated with increased visible light absorption and effective separation of photogenerated carriers. This work provides a new and powerful approach for the preparation of hydrogenated titanium dioxide with switchable defect control, and striking improvement of photocatalytic activity.

Automated summary

The introduction of hydrogen into TiO2 greatly enhances its photocatalytic properties, leading to a 60 times enhancement of photocatalytic hydrogen evolution activity. Hydrogenated TiO2 with switchable defects is synthesized through a one-step wet-chemistry method and controlled annealing. The obtained hydrogenated TiO2 exhibits improved visible light absorption and efficient separation of photogenerated carriers, resulting in significantly enhanced photocatalytic activity.