Green fabrication of Cu/pistachio shell nanocomposite using Pistacia Vera L. hull: An efficient catalyst for expedient reduction of 4-nitrophenol and organic dyes

A facile and rapid biosynthesis of copper nanoparticles (CuNPs) is presented here. This protocol also delivers the CuNPs immobilized on the surface of waste pistachio shell (PS), as an environmentally benign support, using pistachio hull extract (PHE), as a reducing and stabilizing agent. The biosynthesis was realized through a very simple and inexpensive one-pot procedure without employing any toxic reductants or capping agents. The biosynthesized CuNPs and copper/pistachio shell nanocomposite (Cu/PS NC) were characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and transform electron microscopy (TEM). The CuNPs and Cu/PS NC were successfully employed as efficient catalysts in the reduction of 4-nitrophenol (4-NP), methylene blue (MB), rhodamine B (RhB) and methyl orange (MO) at ambient temperature. Cu/PS NC has shown to be a highly effective and easily recyclable catalyst, as it can be reused repeatedly without appreciable decrease in its catalytic activity. In view of these properties, Cu/PS NC was employed as the packing material of a flow reactor for running the reduction of 4-NP into 4-AP expediently in a continuous flow manner. The flow reactor was successfully tested for simultaneous reductive degradation of the dyes contaminated the real waste-water samples collected from the drains of different local textile and drug industries. The methods presented here are environmentally friendly processes and highly beneficial to address the industrial requirements.