Hierarchical photoanode of rutile TiO2 nanorods coupled with anatase TiO2 nanosheets array for photoelectrochemical application

Hierarchical rutile/anatase TiO2 heterogeneous film for photoelectrochemical application is reported in the work. The TiO2 heterogeneous film is fabricated by two-step hydrothermal method and possesses high light harvesting property. The heterojunction formed at the interface between anatase and rutile facilitates photogenerated charge carrier separation, resulting in reduced electron recombination with holes in the electrolyte. The optimal photocurrent density of bare TiO2 heterogeneous film was 0.90 mA/cm2 at a potential of 0 V versus Ag/AgCl. In addition, the TiO2 heterogeneous film offers a large surface area for quantum dots anchoring and exhibits a significant improvement in photoelectrochemical performance. The photocurrent density of PbS/CdS co-sensitized TiO2 heterogeneous film was enhanced to 7.72 mA/cm2. The results indicate that the designed TiO2 heterogeneous structure possesses superior charge separation efficiency and photoelectrochemical properties.