Biosynthesis of Ag/almond shell nanocomposite as a cost-effective and efficient catalyst for degradation of 4-nitrophenol and organic dyes

Silver nanoparticles have been immobilized on the surface of waste almond shell using Ruta graveolens sleeves extract as a reducing and stabilizing agent in the present work. FT-IR spectroscopy, photoluminescence spectroscopy, X-ray diffraction (XRD) patterns, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM) were used to characterize the almond shell supported silver nanoparticles. The diameters of AgNPs on the almond shell were mostly in the 5–15 nm range. The catalytic performance of the synthesized catalysts was studied in reduction of 4-nitrophenol (4-NP), rhodamine B (RhB) and methylene blue (MB) at ambient temperature. AgNPs/almond shell was found to be a highly active and recyclable catalyst in the related reaction, which can be recovered and reused seven times with no appreciable loss of catalytic activity.