Abstract: Photocatalytic water splitting has increasingly attracted attention as one of the most useful methods of converting solar energy into chemical fuel. However, the undesirable reverse reaction significantly limits the enhancement of efficiency. Herein, we fabricated an Au nanorods/TiO₂ nanodumbbells structure photocatalyst (Au NRs/TiO₂ NDs) via a facile synthetic strategy, which has spatially separated oxidation and reduction reaction zones. Owing to the unique structure, the charge separation of these photocatalysts can be significantly improved and the reverse reaction can be efficiently inhibited. The photogenerated electrons were injected from the TiO₂ to the Au NRs, and a positively charged TiO₂ region and negatively charged Au region were formed under UV irradiation. An enhanced hydrogen production performance was obtained compared with that seen in normal Au-TiO₂ heterostructure. Under optimized conditions, the H₂-production rate can reach up to 60,264 μmol/g/h, about six times higher than previously reported Au/TiO₂ photocatalysts. Besides this, our work also demonstrates the key factors of precise synthesis of the Au NRs/TiO₂ NDs structure, which provides a new perspective and experience for the design of similar catalysts.

Key words: Au nanorods, Dumbbell structure, Photocatalytic water splitting, Controllable synthesis