Green synthesis of Ag nanoparticles on the modified graphene oxide using Capparis spinosa fruit extract for catalytic reduction of organic dyes

Abstract

The utilization of various plants extracts for the green synthesis of nanoparticles is growing rapidly due to its widespread application in green chemistry. In the present study, a new green nanocomposite (Ag NPs-F-rGO) has been prepared by using Capparis spinosa fruit extract as a reducing factor. The organic groups were located on the surface of graphene oxide to increase the active sites of the nanocatalyst. The catalytic performance of the resulting nanocatalyst was examined for the reduction of 4‐nitrophenol (4‐NP), methylene blue (MB), methyl orange (MO), and rhodamin (Rh6g) in the presence of NaBH4 at room temperature. The apparent rate constants for 4-NP, MB, MO, and Rh6g reduction were calculated to be 0.020 s−1 (2 mg catalyst), 0.024 s−1 (2 mg catalyst), 0.023 s−1 (2 mg catalyst), and 0.008 s−1 (2 mg catalyst), respectively. The results show that Ag NPs-F-rGO nanocatalyst has good activity and recyclability, and can be reused several times without major loss of activity in the reduction process. The structure, morphology, and crystallinity phases of prepared nanocomposite (Ag NPs-F-rGO) were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray powder diffraction (XRD), respectively. The magnetic Ag NPs-F-rGO nanocomposite was prepared by adding Fe3O4 NPs and characterized by a vibrating-sample magnetometer (VSM).