Enhanced photoelectrochemical and photocatalytic performance of TiO2 nanorod arrays/CdS quantum dots by coating TiO2 through atomic layer deposition

TiO2 nanorod arrays/CdS quantum dots/ALD-TiO2 nanostructures were fabricated as photocatalyst and its related properties were investigated comprehensively. Enhanced photoelectrochmical properties are observed and the degradation rate of methyl orange under visible light is enhanced by ca. 156% compared to the nanorod arrays/CdS quantum dots, which is due to the enhancement of the separation of electrons-holes induced by the introduction of the ultrathin TiO2 top layer. Moreover, the stability of the TiO2 nanorod arrays/CdS quantum dots is increased by the ALD-TiO2 coating. These results suggest that the design of TiO2 nanorod arrays/CdS quantum dots/ALD-TiO2 nanostructures gives a promising strategy to improve the photoelectrochemical and photocatalytic properties in solar energy conversion, along with reduced photo-corrosion in the semiconductor-semiconductor heterojunction. (C) 2014 Elsevier Ltd. All rights reserved.