Nanocomposite with high adsorption activity developed using stabilized silver modified alumina and TiO₂-NPs...

Multifunctional nanocomposites Ag/Al₂O₃/TiO₂@β-cyclodextrin-graphene oxide (AATG) incorporating graphene oxide sheets, TiO₂, and Ag/Al₂O₃ nanoparticles were prepared in two steps. We benefited from the inherent properties of β-cyclodextrin to create a stable aqueous graphene solution capable of self-assembling in situ grown TiO₂ nanoparticles on graphene nanosheets. Ag/Al₂O₃ catalysts with a high surface-to-volume ratio were prepared by a combustion technique in solution with urea as a new fuel. The synthesized nanoparticles were also characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface analysis, and BJH pore analysis. FE-SEM was used to evaluate the morphology of β-cyclodextrin-graphene oxide, Ag/Al₂O₃ and AATG nanoplatforms. This research examined the use of AATG as a novel nanocomposite for removing methylene blue from water and compared its effectiveness with that of TiO₂@β-cyclodextrin-graphene oxide (TG) as an intermediate material to assess the impact of the final composite and its components on absorption. The effect of pH, temperature, time, and dye concentration on the reaction rate was investigated. The results showed that at pH above 4, the adsorption rate of MB by AATG gradually increased to about 98%. The results also show that methylene blue is more effectively removed at higher temperatures, implying that the adsorption is temperature dependent and the elimination process is endothermic. The adsorption kinetics, isothermal studies, and thermodynamic analysis were also evaluated. The adsorption data showed excellent agreement with pseudo-second order models (R² > 0.99) and the Langmuir isotherm. The AATG nanocomposites showed excellent adsorption activity, making them potential candidates for water treatment.