Synthesis and optical analysis of nanostructured F-doped ZnO thin films by spray pyrolysis: Transparent electrode for photocatalytic applications

Abstract

In this paper, spray pyrolysis as a valuable cost-effective deposition technique was used to obtain nanostructured thin films of ZnO and ZnO: F on soda-lime glass substrates at 400 °C. The crystal structure and surface morphology of the as-deposited thin films have been characterized by the X-ray diffraction (XRD) technique and high-resolution atomic force microscope (AFM). XRD patterns indicated the wurtzite hexagonal structure of the deposited films with mean grain size in nanoscale. AFM and XRD confirmed that the mean grain size of ZnO film was increased with the F doping level. The optical parameters like refractive index, absorption coefficient, and optical bandgap have been obtained through Swanepoel's model depending on the transmission spectra of the deposited films. The direct optical band gap of ZnO film was slightly decreased with the F doping level. The single oscillator model was applied to determine the dispersion parameters of the films under study. The photocatalytic activity of the ZnO and ZnO: F thin films for the phenol photodegradation under UV-irradiation also has been evaluated to purify water from phenol as colorless organic waste. 3%F doped ZnO film has the highest constant rate of phenol photodegradation with high stability in reusing and recycling, confirming the high efficiency of F doped ZnO films as environmentally friendly photocatalysts for the removal of phenol from water.