Abstract
Yttrium doped ZnO nanorod array films are hydrothermaliy grown on fluorine doped tin oxide substrates. The yttrium doped ZnO samples maintain the same wurtzite crystal structure and nanorod morphology as those of the undoped samples, but they shows much enhanced photoelectrochemical water splitting performance. It is found that yttrium doping not only enhances the light absorption of the ZnO, but also provides more donors for ZnO and thereby enhances the conductivity of the ZnO nanorods. Moreover, the charge carrier lifetime of ZnO becomes longer after yttrium doping. These changes in the electronic structure of ZnO caused by yttrium doping significantly improve its photoelectrochemical performance. Under AM 1.5 G illumination at 100 mW/cm~2 and a potential of 1.23 V vs. reversible hydrogen electrode, the yttrium doped ZnO samples can get a photocurrent density of - 0.50 mA/cm~2, while the undoped ZnO samples only show photocurrent densities of ~ 0.30 mA/cm~2 under the same conditions. Considering that ZnO has advantages of low cost, environmental friendliness and simple and mild preparation process, it is expected that the yttrium doped ZnO nanorod array films will provide valuable platforms for a wide photocatalytic applications, not just limited to photoelectrochemical water splitting.
NSTL
Elsevier