The FESEM image of the nanorods is shown in Fig. 5. The FESEM image reveals that the diameters of the ZnO nanorods are in the range 25–75 nm, and length in the range of 500 nm−1.5 μm. The EDXA analysis presented in Fig. 6 shows that the as-prepared ZnO nanorods contain Zn and O only (the Al peak in the spectrum is due to the background from the FESEM Al grid) and in the atomic ratio of 1:0.7, indicating the presence of oxygen deficiency, which might have been caused during the rapid formation of ZnO nanorods under microwave irradiation. Figure 7 shows the TEM image of the representative nanorods which further supports the results obtained by the FESEM images. The ED pattern of the nanorods is shown in Fig. 8 suggests the single crystalline nature of the nanorods and can be indexed to the wurtzite single phase ZnO. The preferential growth direction of these rods was along the c axis of the crystal lattice.