Green synthesis of a Cu/MgO nanocomposite by L. extract and investigation of its catalytic activity in the reduction of methylene blue, congo red and nitro compounds in aqueous media.

This work reports the green synthesis of a Cu/MgO nanocomposite using L. extract as a reducing agent without stabilizers or surfactants. The immobilization of Cu NPs was confirmed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and energy dispersive X-ray spectroscopy (EDS). The Cu/MgO nanocomposite acts as a heterogeneous and recyclable catalyst for the reduction of 4-nitrophenol (4-NP), 2,4-dinitrophenylhydrazine (2,4-DNPH), methylene blue (MB) and congo red (CR) using sodium borohydride in aqueous media at room temperature. The catalyst was recycled multiple times without any significant loss of its catalytic activity.