Aqueous chemically grown ZnO nanorods (NRs) arrays were sensitized by CdSe quantum dots (QDs) and were investigated as photoanode for photoelectrochemical water splitting under visible light (>420 nm) illumination. Significant enhancement of the factors 1.6 and 6 was observed for CdSe (QD)-sensitized nonannealed and annealed samples of ZnO NRs over pristine ZnO NRs arrays, respectively. The highest photocurrent density of 2.48 mA/cm(2) was registered for the annealed CdSe (QD)/ZnO (NR) arrays films at zero applied voltage and 100 mW/cm(2) (AM 1.5 G, Air Mass 1.5 Global) power density and their corresponding photocurrent density for pristine ZnO NR array was recorded as 0.41 mA/cm(2). (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3473788] All rights reserved.