Crystal Facet Engineering and Hydrogen Spillover-Assisted Synthesis of Defective Pt/TiO2-x, Nanorods with Enhanced Visible Light-Driven Photocatalytic Activity

Hydrogen spillover can assist the introduction of defects such as Ti-3(+) and concomitant oxygen vacancies (V-O) in a TiO2 crystal, thereby inducing a new level below the conduction band to improve the conductivity of photo-generated electrons and the visible light absorption property of TiO2. Meanwhile, crystal facet engineering offers a promising approach to achieve improved activity by influencing the recombination step of the photo-generated electrons and holes. In this study, with the aim of achieving enhanced visible light-driven photocatalytic activity, rutile TiO2 nanorods with different aspect ratios were synthesized by crystal facet engineering, and Pt-deposited TiO2-x nanorods (Pt/TNR) were then obtained via reduction treatment assisted by hydrogen spillover. The reduction treatment at 200 degrees C induced the formation of surface Ti3+ exclusively, whereas surface Ti3+ and V-O were formed by performing the reduction at 600 degrees C. The Pt/TNR with a higher aspect ratio reduced at 200 degrees C exhibited the highest activity in photocatalytic H-2 production under visible light irradiation owing to the synergistic effect of the introduction of Ti3+ defects and the spatial charge carrier separation induced by crystal facet engineering.