Synthesis of TiO۲/CD and TiO۲/Ag/CD Nanocomposites and Investigation of Their Visible Light Photocatalytic Activities in the Degradation of Methylene Blue

The surface of bio-synthesized TiO۲ nanoparticles was modified with a silane agent to generate the chemical link to the preparation of TiO۲/β-cyclodextrin and TiO۲/Ag/β-cyclodextrin nanocomposites. The structure of synthesized nanocomposites was identified using different techniques, including FTIR, DRS, XRD, ICP, TGA, FESEM, and EDX MAPPING. The photocatalytic activity of the nanocomposites was investigated in the degradation of methylene blue dye in aqueous solution under sunlight irradiation (۴۰۰-۷۰۰ nm). The effective factors in the degradation of methylene blue dye including, nanocomposite dosage, initial methylene blue concentration, and irradiation time were studied. The results revealed that under optimum degradation conditions (۰.۰۱ g nanocomposite, initial methylene blue concentration of ۱۰ ppm, and ۱۲۰ min sunlight exposure time), TiO۲/Ag/β-cyclodextrin exhibited the highest photocatalytic activity among the tested nanocomposites. The photocatalytic efficiency of nanocomposites showed the order: TiO۲/Ag/β-cyclodextrin (۹۹.۳۸%)> TiO۲/β-cyclodextrin (۸۴.۱%)> TiO۲ nanoparticles (۶۳.۷۶ %). Photocatalytic activity of the synthesized nanocomposites revealed that these materials could be promising candidates for the degradation of various pollutants.

Keywords:

β -cyclodextrin , TiO۲ nanocomposites , photocatalyst , Methylene blue , Visible light