Germanium (Ge) doped zinc oxide (ZnO) nanorods were fabricated on silicon substrate using a simple thermal evaporation method at different contents Ge (0-30 at.%). High resolution transmission electron microscopy (HRTEM) images shows that prepared ZnO nanorods are structurally uniform and single crystalline. The diameters of the nanorods are in the range of 80-150 nm with typical length of 3 mu m. The samples are evaluated by the determination of their photonic efficiencies for degradation of methylene blue. The photonic efficiency is increased with increasing the Ge content up to 13 at.% showing maximum photonic efficiency as 2.99% and it is found to be about 2 times higher than that of undoped ZnO nanorods because Zn2GeO4 is grown and decorated ZnO nanorods and make heterojunction between Zn2GeO4 and ZnO nanorods. This is the first report focusing on Ge-catalyzed growth of ZnO nanorods for enhanced photonic efficiencies. (C) 2014 Elsevier B.V. All rights reserved.