Enhanced photoelectronic properties of single crystal TiO2 nanosheet array films by selective deposition of CdS nanoparticles on their {101} facets

Abstract

Single crystal TiO₂ nanosheet array films with dominant {001} facets were synthesized on FTO by a hydrothermal method. A simple strategy for the selective deposition of CdS nanoparticles on the low energy {101} facets by controlling the F content on the surface of TiO₂ nanosheets is developed. For CdS/TiO₂, under light irradiation, the photo-generated electrons flow from the {001} to {101} facets; meanwhile, the photo-generated electrons transfer from the CdS nanoparticles to the TiO₂ nanosheets. The deposition of CdS nanoparticles on the {101} facets will shorten the pathways that the electrons must travel. Herein, the synergistic effect of the selective deposition of CdS nanoparticles on the {101} facets of TiO₂ nanosheets and the different band edge positions of the {001} and {101} facets would facilitate the spatial separation of electrons and holes on different facets, leading to enhanced photoelectronic performance.