0000000000236523
AUTHOR
Mohamed Faouzi Nsib
Pickering Emulsions of Fluorinated TiO2: A New Route for Intensification of Photocatalytic Degradation of Nitrobenzene
International audience; Fluorination of the TiO2 surface has been often reported as a tool to increase the photocatalytic efficiency due to the beneficial effects in terms of production of oxidizing radicals. Moreover, it is shown that the unique amphiphilic properties of the fluorinated TiO2 (TiO2-F) surface allow one to use this material as a stabilizer for the formulation of Pickering emulsions of poorly soluble pollutants such as nitrobenzene (NB) in water. The emulsions have been characterized in terms of size of the droplets, type of emulsion, possibility of phase inversion, contact angle measurements, and optical microscopy. The emulsified system presents micrometer-sized droplets of…
Effect of Urea–Hydrogen Peroxide Content on the Photocatalytic Activity of Zinc Oxide Nanoparticles
ZnO nanoparticles (NPs) were synthesized using zinc acetate dihydrate, ethanol, and oxalic acid as precursor, solvent, and complexing agent, respectively, and urea–hydrogen peroxide (UHP) as, simultaneously, nitrogen precursor and oxygen donor. The structural, morphological, textural, and optical properties of ZnO photocatalysts were investigated using different characterization methods such as XRD, SEM, BET, and UV-Vis-DRS. The XRD patterns showed that the products consisted of ZnO and revealed the presence of nitrogen. SEM images revealed the agglomeration and aggregation of NPs. The photocatalytic activity of ZnO samples was estimated based on the photo-oxidation of 2-propanol under UV i…
Photocatalytic degradation enhancement in pickering emulsions stabilized by solid particles of bare TiO 2
Pickering emulsions provide a new way to enhance the efficiency of photocatalytic degradation of water-insoluble pollutants. Indeed, the semiconductor solid particles dually act as the photocatalyst and stabilizer of the emulsion droplets whose size dramatically affects the photocatalytic reaction. The present work aims at the validation of this concept by using bare TiO 2 without any surface modification. Nanostructured TiO 2 has been prepared by a simple sol-gel process and characterized by X-ray diffraction, specific surface area analysis, scanning electron microscopy, and diffuse reflectance spectroscopy. The emulsions were prepared by using 1-methylnaphthalene (1-MN) as a model organic…
Surface and Electronic Features of Fluorinated TiO 2 and Their Influence on the Photocatalytic Degradation of 1-Methylnaphthalene
International audience; Surface fluorination improves the photocatalytic activity of TiO2, and the influences of various features of fluorinated TiO2 (TiO2–F) have often been discussed in the literature. The present paper addresses the changes induced by surface fluorination on the morphological, structural, surface, and electronic features of TiO2. In particular, X-ray diffraction, specific surface area analysis, and transmission and scanning electron microscopy give evidence that surface fluorination does not affect the structural properties and the morphology of TiO2 nanoparticles. In contrast, fluorination induces changes of surface and electronic properties. Chemical and thermogravimet…