LAUSR

Abstract In this paper, for the first time, SnO2-bentonite nanocomposites were synthesized through immobilization of SnO2 nanoparticles on natural bentonite using aqueous extract of jujube fruit. In this simple and safe procedure, the jujube acted as a naturally-sourced reducing agent. The biosynthesized SnO2-bentonite nanocomposites were characterized by various techniques such as SEM (scanning electron microscopes), EDX (energy-dispersive X-ray spectroscopy), TEM (transmission electron microscope), XRD (X-ray diffraction), FT-IR (Fourier-transform infrared spectroscopy), and N2 adsorption-desorption to investigate the morphology, chemical elemental composition, crystalline size, functional groups and surface area of the biosynthesized nanocomposites. The supported SnO2 nanoparticles on bentonite were observed obviously in the SEM image of SnO2-bentonite nanocomposites. The EDX analysis of biosynthesized nanocomposites was well indicated the successful immobilization of SnO2 nanoparticles on bentonite. The average particle size of SnO2-bentonite nanocomposites was evaluated based on the TEM and found to be 18 nm. The crystalline nature of the SnO2-bentonite nanocomposites was confirmed via XRD analysis. The presented functional groups in biosynthesized SnO2-bentonite nanocomposites were identified by FTIR spectral analysis. Afterward, then, the photocatalytic performance of SnO2-bentonite nanocomposites was studied for the efficient degradation of organic dyes (methylene blue and eriochrome black-T) without using any toxic reducing agents under solar irradiation. The new SnO2-bentonite nanocomposites as a very stable catalyst could be tolerated the reaction conditions and reused at least three times without remarkable loss of activity.