Photocatalytic Activity of Bilayer TiO₂/ZnO and ZnO TiO₂ Thin Films

Abstract

Thin film is a thin material that is resulting from the condensation of species through the deposition of atoms on the substrate. Thin films are usually used in the production of electronic devices, optical coatings, solar cells, and for decorative items. The bilayer of TiO 2 /ZnO and ZnO TiO 2 thin films have some advantages such as can enhance the surface state and surface atomic mobility, which are useful for improving the photocatalytic activity. The motivation to a used double layer of ZnO and TiO 2 is to enhance the properties and photocatalytic activity using the different deposition temperature between the layers. The structural of ZnO/TiO 2 thin films were studied using X-Ray diffraction (XRD). Field Emission Scanning Electron Microscope (FESEM) was used to determine the surface morphology of ZnO/TiO 2 thin films. The photocatalytic activity of ZnO/TiO 2 thin films was analysed using the photodegradation of methylene blue (MB) solution. The XRD analysis revealed that highest anatase crystalline phase for TiO 2 growth with orientation (1 0 1), while the ZnO crystal phase, zincite occurred at the highest intensity with (1 0 1) orientation.. The bilayer TiO 2 /ZnO thin film had the highest reaction rate, K, which is 0.0972 h-1 for photocatalytic activity. The characteristics of bilayer TiO 2 /ZnO and ZnO/TiO 2 thin-film is strongly influenced by the calcination temperature and the presence and combination between the two types of materials.