Enhanced photocatalytic activity of ZnO nanorods grown on Ga doped seed layer

摘要

ZnO nanorods have been successfully grown on Ga doped (0-5 wt%) ZnO seed layer by using simple hydrothermal method. Changing Ga content in the seed layers lead to formation of ZnO nanorods with high aspect ratio and increased density. The effects of Ga doped seed layer on optical and structural morphology of ZnO nanorods are investigated in detail by using Field-emission scanning electron microscope (FESEM), X-ray diffraction (XRD) and Photo luminescence spectroscopy (PL). It has been observed that the Ga doped seed layer strongly affected the structural morphology of ZnO nanorods. XRD results show that all the samples have hexagonal wurtzite shape and (002) is preferred direction of growth. The intensity of (002) peak increases with increasing Ga concentration in seed layer indicating that the Ga doped seed layer has promoted growth of nanorods along (002). SEM images show a decrease in diameter of ZnO nanorods with increasing Ga concentration in seed layer. The PL spectra of all the samples have two emission bands, UV and defect emission. UV emission shows a small blue shift with increasing Ga concentration in seed layer. The photocatalytic activity of as grown ZnO nanorods increases with aspect ratio (length) and density.