Effet Du Dopage Par Ag Sur La Dégradation Photocatalytique Des Films Minces D'oxyde De Nickel (NiO) Préparés Par Procédé Spray- Pyrolyse

Abstract

This thesis focuses on the fabrication and characterization of Ag-doped NiO thin films for the photodegradation of dyes. The films were prepared using the spray pyrolysis technique on glassn substrates and subjected to various characterization techniques. X-ray diffraction (XRD) analysis confirmed the cubic structure of both NiO and Ag-doped NiO films. Energy-dispersive spectroscopy (EDX) was employed to determine the atomic concentrations of Ni, O, and Ag in the films. The thin films exhibited an average transmittance of approximately 51% in the visible region of the spectrum. Significant absorption was observed at 364 nm, corresponding to the optical bandgap of NiO. Ag doping had a minimal impact on the film's transmittance, and no systematic variation in Ag concentration was observed. The bandgap energy was measured between 4.09 and 3.92 eV, decreasing with a 2% Ag content and increasing to 4.01 eV with 4% Ag. The photodegradation of methylene blue dye was investigated using the NiO and Ag-doped NiO thin films. Results demonstrated rapid dye degradation within the first 40 minutes, followed by a gradual decrease in degradation efficiency. The addition of Ag significantly enhanced the degradation efficiency, particularly with a 4% Ag concentration. This thesis successfully presents the fabrication of Ag-doped NiO thin films for dye photodegradation. The results suggest the promising potential of these thin films in the field of dye degradation, offering new prospects for applications in this domain.