Effect of y-irradiation on the growth of ZnO nanorod films for photocatalytic disinfection of contaminated water

Abstract

The growth of ZnO nanorods on a flat substrate containing ¿-irradiated seeds and their ability to photocatalytically eliminate bacteria in water were studied. The seed layer was obtained, by the spray pyrolysis technique, from zinc acetate solutions ¿-irradiated within the range from 0 to 100 kGy. Subsequently, to grow the rods, the seeds were immersed in a basic solution of zinc nitrate maintained at 90 °C. The rate of crystal growth on the seed layer during the thermal bath treatment was kept constant. The resulting materials were characterized morphologically by scanning electron and atomic force microscopies; X-ray diffraction was used to study their morphology and structure and ultraviolet–visible spectroscopy to determine their absorbance. The obtained seed films were morphologically dependent on the radiation dose and this was correlated with the ZnO nanorod films which presented a texture in the (0 0 2) direction perpendicular to the substrate. The rods have a hexagonal mean cross section between 20 and 140 nm. Using these rods, the photocatalytic degradation of Escherichia coli bacteria in water was studied; a positive influence of the crystalline texture on the degradation rate was observed.