Influence of pyrolytic seeds on ZnO nanorod growth onto rigid substrates for photocatalytic abatement of Escherichia coli in water

ZnO nanorods (ZnO NRs) were grown on ZnO seeded fluorine doped tin oxide (FTO) substrates at low temperatures (90 degrees C) from Zn2+ precursors in alkaline aqueous solution. The ZnO seeds were deposited on the FTO substrate heated at 350 degrees C by spray pyrolysis of a zinc acetate solution in a water ethanol mixture. The structure of seeds was tuned by the ethanol water ratio, Gamma, which controls the solvent evaporation rate of drops impinging the substrate. The relationship between the microstructure and optical properties of the ZnO NR films and the photocatalytic antibacterial activity for Escherichia coli abatement, was determined through a detailed characterization of the material. The higher photocatalytic antibacterial activity was performed by ZnO NR films grown on seeds deposited from solutions with Gamma in the 0.0-0.03 range. With these films, the population of viable E. coli dropped more than six orders, from 8 x 10(8) to 4 x 10(2) CFU. These results show the potential of these materials in water disinfection.