Hybrid clay-based materials for organic dyes and pesticides elimination in water.

Autor: Mbognou, Marlène Huguette Tsaffo, Lambert, Stéphanie D., Caucheteux, Joachim, Farcy, Antoine, Alié, Christelle, Fagel, Nathalie, Woumfo, Emmanuel Djoufac, Mahy, Julien G.
Zdroj: Journal of Sol-Gel Science & Technology; Feb2023, Vol. 105 Issue 2, p461-470, 10p
Abstrakt: Natural clay, extracted from Cameroon, was modified by ion exchange to produce 4 different clays. These latter were modified with photocatalytic semiconductor like ZnO to produce efficient hybrid materials for pollutant removal in water. ZnO was synthesized by the soft sol–gel chemistry method. The results showed that the clay belonged to the smectite family and was composed of different crystalline phases. When the hybrid materials were produced, mix crystalline patterns were obtained with both smectite and ZnO wurtzite phases. The ICP-AES analysis showed that similar ratio between ZnO and clay were obtained for the 4 hybrid materials (30 wt% of ZnO and 70 wt% of clay). The SEM observation of the samples had shown that the hybrid materials had the clay structure as skeletal structure (sheet like structure) with the ZnO spherical materials grafted at the surface, giving a good exposure to light to maintain photocatalytic property. Then, the pollutant removal property of the samples was evaluated on three different model pollutants: p-nitrophenol (PNP), Malachite green (MG) and Diamant brilliant violet (DBV). On PNP, no adsorption was observed, and photocatalytic property was necessary to eliminate this molecule. With the best hybrid material (Clay/Cu2+/ZnO), 80% of PNP degradation was observed after 6 h of illumination. On MG and DBV, similar behavior was observed. Indeed, the clays and three out of four hybrid materials adsorbed completely both pollutant after 2 h of contact. Only pure ZnO and Clay/ZnO needed illumination to degrade completely both molecules. This study showed the possibility to obtain very efficient hybrid materials for pollutant removal in water with the use of inexpensive natural clay modified with a low amount of photocatalytic material (ZnO around 30 wt.%). Highlight: Natural clay was modified by ion exchange to produce 4 different clays. These clays were modified with ZnO to produce hybrid materials for pollutant removal in water. The hybrid materials had the clay structure with the ZnO spherical materials grafted at the surface. p-nitrophenol (PNP), Malachite green (MG) and Diamant brilliant violet (DBV) were used as model pollutants. All three molecules can be removed from the water either by adsorption and/or photocatalysis. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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