Yohan Richardson

Effective coupling of phenol adsorption and photodegradation at the surface of micro-and mesoporous TiO2-activated carbon materials

Novel titania supported activated carbon catalysts were prepared by a straightforward titania coating route of a microporous activated carbon (AC) derived from shea nut shells, and investigated in phenol photocatalytic degradation. The proposed coating method enables a fixation of the preformed titania anatase nanoparticles (TiO2 NPs) in the external porosity thus allowing their accessibility towards UV irradiation, without causing any reduction of the AC specific area. Interestingly, the coating treatment reshapes the porous texture of the as-prepared TiO2–AC composite materials resulting in an improvement of the adsorption capacity and the formation of an additional mesoporosity on the TiO2-AC surface. Photocatalytic experiments carried out in a batch reactor led to 97% elimination rate of phenol in an aqueous solution with the AC catalysts containing TiO2 NPs in the range from 11 to 34 wt%. The photodegradation performance of the TiO2–AC catalysts was maintained over several successive cycles, without the need of any regeneration treatment. Considering both the textural and microstructural features of the composite materials and their associated phenol removal kinetics, in this paper, we provide new insights into phenol photodegradation pathway involving an effective coupling of adsorption and photodegradation functionalities, resulting in a photo-assisted regeneration mechanism of the catalyst.

Removal of Methylene Blue Dye by Fenton-like Process Using Laterites

Several synthetic dyes are produced yearly around the world. MB has mostly been used as prototypical dye and has two aromatic rings which are hardly degradable. Advanced Oxidation Process (AOPs) are effective in the degradation of bio-reluctant organic pollutants. Fenton process is an AOP, based on the generation of hydroxyl radicals with hydrogen peroxide (H2O2) and ferrous iron (Fe2+). However, the homogeneous process generates, Iron sludges due to the complexity of the Iron species mainly at pH up to 3. Thus, the use of solid catalysts has been recommended in previous studies to get rid of these drawbacks.