Catalytic Reduction of 4-Nitrophenol Using Biogenic Silver Nanoparticles Derived from Papaya (Carica papaya) Peel extract

Abstract

A facile and green method is described for the synthesis of Silver (Ag) nanoparticles (NPs) from the extract of Papaya Peel as capping and reducing agent. The green synthesized Ag NPs were characterized by diverse techniques such as powder X-ray diffraction (XRD), UV-visible, Fourier transform-infrared spectroscopy (FTIR) and Transmission electron microscopy (TEM) coupled with X-ray energy dispersive spectroscopy (EDS) techniques. These clearly reveal that the structure of the synthesized silver nanoparticles was face centered cubic. The nanoparticles obtained from Papaya Peel extract were spherical shape with an average diameter of 3-5 nm. Furthermore, the catalytic activity of synthesized Ag NPs in the reduction of 4-nitrophenol (4-NP) was studied by UVvis absorption spectroscopy. The synthesized Ag NPs have a good catalytic activity on the reduction of 4-nitrophenol (4-NP) by Papaya Peel extract which is confirmed by the decrease in absorbance maximum values of 4-nitrophenol (4-NP) with respect to time using UV-vis absorption spectroscopy. An efficient reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of Ag NPs and NaBH4 was observed and was found to depend upon the nanoparticle size or the peel extract concentration used for synthesis.