ZnO and ZnO-nanorods thin films as supported catalysts for enhanced dye degradation

Zinc oxide (ZnO) thin films and ZnO nanorod thin films were prepared via sol-gel and chemical bath deposition methods at low temperatures, respectively, and tested for their ability to photocatalytically degrade Methylene Blue. Both films were oriented in the c-axis in the (002) plane, but the crystallinity of the ZnO nanorod film was better than the ZnO seed layer. The surface morphology of the ZnO film was in ripple form, allowing the ZnO-nanorods to grow around the ripples and increase the contact area with the solution. The ZnO nanorod film enhances the adsorption process. After 2.49 hours of irradiation, 50% of the dye degrades, and 80% degrades after 6 hours. The structural properties, such as good crystallinity and the orientation in the (002) plane, help improve the films’ photocatalytic efficiency. ZnO and ZnO-nanorod films could be considered efficient and green options for the photocatalytic process of decomposing organic pollutants in an aqueous medium.