Facile green syntheses of palladium nanoparticles using fruit and aloe vera juices, and their surface–enhanced Raman scattering (SERS) activities

Abstract

Biogenic reduction of metal precursors to corresponding metal nanoparticle (NP) is growing interest among scientists. In the present study, we explore the use of common cheap apple, orange, and aloe vera juices for the synthesis of industrially important stable palladium (Pd) NPs in a rapid room–temperature method without using any external surfactants or capping agents. The formation of Pd NPs is confirmed by powder x-ray diffraction (PXRD), x-ray photoelectron spectroscopy, and ultraviolet–visible spectroscopy. Transmission electron microscopic images clearly show that the spherical Pd NPs have a uniform size distribution in the ranges of 2–25 nm depending on the type of juice. The Pd NPs obtained using apple (Pd–Aj) and orange juices (Pd–Oj) are more uniform and smaller in size than those obtained using aloe vera juice (Pd–Av). The sugars and polyols (with OH–groups) of the juices act as stabilizers of the Pd NPs as confirmed by thermogravimetric and Fourier transform infra–red analyses. Furthermore, the as–synthesized Pd NPs exhibit size−dependent SERS activities and are suitable for lower–level detection (10−6 M) of environmentally harmful methylene blue dye in water.