PhD project

Forecasts for the global textile dyes market would indicate a growth from some 7 billion US$ in 2019 (before the Covid pandemic) to more than 13 billion US$ in 2027, despite stringent environmental regulations.This high consumption of dyes will result into an increase in water pollution. Already now, 100 tons of dyes are released annually in effluents by industry. An efficient and promising way to treat this kind of pollution is photocatalysis. And currently, the most promising semiconductor in this field is ZnO. This wide band-gap semiconductor is known for its chemical stability, its non-toxicity, its interesting optoelectronic properties, and the relative ease to deposit it in thin films.

ZnO with its band-gap at 3.4 eV only absorbs UV. However, if we want to use the solar spectrum as an energy source for photocatalysis. But, UV radiation represents only a few percent of the solar spectrum. So,the incorporation of silver nanoparticles in the ZnO matrix should improve the absorption of the nanocomposite in the visible range. Moreover, the beneficial contribution of silver to photocatalytic properties has been widely reported such as band-gap narrowing, charge separation, plasmonic effects, etc.

this material has been studied in detail in different field applications. all these studies have been done in bulk, powder; and films forms. surprisingly, very little research has been done on nanocomposite based on ZnO very thin films. so, a new study can be investigated to discover the properties of nanocomposite thin films and interactions between ZnO and Ag nanoparticles.

This project proposes optical, structural, and morphological studies of nanocomposite thin films based ZnO. these thin layers will be used to dergade organic dyes molecules and antibiotics like indigo carmine and amoxicillin.

we will start by the elaboration of silver nanoparticles by sonoelectrochemical technique then the thin films depositions using a simple technique sol-gel coupled by spin-coating. the surface state of ZnO/Ag thin films will be shown by scattering electronic microscope coupled with EDXs, and atomic force microscope. Structural properties of films elaborated will be determined by X ray diffraction. the thickness of these films will be obtained by ellipsometry and measured using a profilometer. optical properties will be obtained using UV-VIS-NIR spectrophotometer and ellipsometry.

The ZnO/Ag NPs will be used to photocatalysis application to dyes molecules degradation. We choose the indigo carmine and the methyl-orange, using UV and White illumination. At the end of this study, a mechanism of dyes degradation will be proposed.