Enhanced photoelectrochemical properties of nanocrystalline TiO₂ electrode by surface sensitization with Cu_xO quantum...

Nanoporous anatase TiO₂ films were fabricated by a screen-printing method, and Cu_xO quantum dots (QDs) were deposited on the TiO₂ films through successive ionic layer adsorption and reaction (SILAR). The amount of Cu_xO QDs on the TiO₂ films are controlled by changing the number of SILAR cycles. The morphology, microstructure, optical, and photoelectrochemical properties of different Cu_xO sensitized TiO₂ films (Cu_xO/TiO₂) were investigated in detail. The nanoporous TiO₂ film offers a large surface area for anchoring QDs. QD deposited samples exhibited a significant improvement in photoelectrochemical performance than the bare of TiO₂. Cu_xO/TiO₂, prepared with 7 SILAR cycles, showed the best photoelectrochemical properties, where the photocurrent density was enhanced to 500.01 μA/cm² compared with 168.88 μA/cm² of bare TiO₂ under visible light. These results indicate that the designed Cu_xO/TiO₂ structure possesses superior charge separation efficiency and photoelectrochemical properties.