Antibacterial activity of ZnO films prepared by anodizing

In the present work, anodizing of zinc foil was investigated in NaOH and oxalic acid electrolytes under the influence of different concentrations of the electrolyte, while temperature and voltage were kept constant. Anodized zinc plates were characterized using scanning electron microscope (SEM), UV–Vis diffuse reflectance spectroscopy (DRS UV–Vis), and X-ray diffraction (XRD) analysis. Characterization of anodized Zn plates using SEM showed that their morphology was significantly influenced by the type and concentration of anodizing electrolyte. XRD analysis indicated that the ZnO thin films were of hexagonal wurtzite structures. From contact angle measurements, it has been observed that the contact angle of anodized film is higher than that of pure zinc foil. Antibacterial results suggest that the parent zinc foil did not show the antibiotic activity, but the anodized zinc oxide is effective both toward Gram-positive bacteria and Gram-negative bacteria.