Examination of interfacial charge transfer in photocatalysis using patterned CuO thin film deposited on TiO2.

We examined the interfacial charge transfer effect on photocatalysts using a patterned CuO thin film deposited on a rutile TiO₂ (110) substrate. Photocatalytic activity was visualized based on the formation of metal Ag particles resulting from the photoreduction of Ag⁺ ions under visible-light illumination. Ag particles were selectively deposited near the edge of CuO film for several nanometer thick CuO film, indicating that interfacial excitation from the valence band maximum of TiO₂ to the conduction band minimum of CuO plays a key role in efficient photocatalytic activity of CuO nanocluster-grafted TiO₂ systems with visible-light sensitivity [ABSTRACT FROM AUTHOR]