Résumé
A natural clay material from Oman (Sarooj Clay) has been used to develop two porous composite materials, clay/carbon and clay/carbon/carbon nanotube composites referred to as Clay/Carbon and Clay/Carbon/CNT respectively. The clay/carbon material was prepared by carbonizing at 800 degrees C under an inert atmosphere (N2) a polymer composite made of a thermosetting phenolic resin as the polymer matrix mixed with a clay powder as the mineral additive. For the clay/carbon/carbon nanotubes material, carbon nanotubes (CNTs) were grown in situ within the material by carbonizing under the same conditions a polymer composite made of a thermosetting phenolic resin, clay powder with ferrocene as a catalyst for CNT growth. The physicochemical characterization, thermal properties, and vibrational analysis of these materials were performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results of these analyses confirm the growth of CNTs within the pores of clay-based composites. BET measurements confirmed an increase in specific surface area and porosity after CNT growth. The adsorption study of AO7 dye revealed that the clay/carbon/CNT mixture is the most efficient, with pseudo-second-order kinetics and a Langmuir isotherm indicating monolayer adsorption. The presence of carbon nanotubes (CNTs) in the clay composite significantly improves its efficiency in the adsorption of the azo dye Acid Orange 7 (AO7) in aqueous solution, due to hydrogen bonding with the clay and pi-pi interactions between CNTs and the dye molecule.