Green mediated synthesis of palladium nanoparticles using aqueous leaf extract of Gymnema sylvestre for catalytic reduction of Cr (VI)

Abstract

Palladium nanoparticles (PdNPs) were synthesised using a microwave technique using Gymnema sylvestre (GSE) leaf extract. PdNPs were tailored to different PdCl2 and plant extract concentrations. Using XRD the crystalline existence of GSE-PdNPs has been established, confirming the formation of face-centered cubic structure. UV–Vis spectra of PdNPs confirmed the reduction of Pd2+ to Pd0. The FTIR spectra indicate the existence of functional groups which are responsible for nanoparticles reduction and progression. The SEM discloses quasi-sphere nanoparticles without agglomeration or aggregation which TEM confirms further. The reduction of Cr (VI) was performed with PdNPs (10 mg/L) and achieved a reduction of 96% within 30 min. In order to investigate the efficient reduction of chromium from Cr (VI) to Cr (III), different reaction system parameters have been optimised.