A ZnO/ZnO: Cr isostructural nanojunction electrode for photoelectrochemical water splitting

The fabrication and photoelectrochemical characterization of a ZnO/ZnO:Cr isostructural nanojunction electrode is presented. When compared to its constituent components the isostructural nanojunction showed superior performance for water splitting under simulated solar light and visible light (λ510. nm) illumination. In the engineered structure, the presence of intra-bandgap states associated with Cr impurities increases optical absorption, and the nanorod morphology provides a direct pathway for transport of photo-excited electrons to the back contact. The overall photoelectrochemical performance of the ZnO/ZnO:Cr engineered structure is relatively low, however the concept may prove to be applicable to more optimized structures or material systems.