Catalytic activity of immobilized Ag and Pd nanoparticles on the magnetic natural zeolite using Chrysanthemum morifolium flower extract in the reduction/decolorization of dyes

In this study, Ag and Pd nanoparticles (NPs) were immobilized on natural zeolite and magnetized zeolite (Fe3O4/natural zeolite) by using an aqueous Chrysanthemum morifolium flower extract, as a green and low-cost method. Different techniques such as FTIR, XRD, FESEM, EDS, and VSM were used for the characterization of prepared nanocomposites. The FESEM and TEM images of nanocomposites showed that the quasi-spherical Ag and Pd NPs with mostly 20–50 nm particles size have successfully formed and are well dispersed on the supports surface. The effect of various parameters such as nanocomposite type, initial dye, NaBH4 concentrations, catalyst dose, and pH were studied in the catalytic reduction/decolorization of three organic dyes. In the absence of NaBH4 or catalyst, no color changes were observed even after 90 min. The reduction rates of the selected dyes in the presence of stable catalysts were found to be in an order of Pd/Fe3O4/natural zeolite Pd/natural zeolite Ag/Fe3O4/natural zeolite Ag/natural zeolite Fe3O4/natural zeolite.