Biogenic and rapid route for the synthesis of palladium nanoparticles by using Roylea cinerea extract and their catalytic activity for Suzuki and Sonogashira coupling reactions and nitrophenol reduction

Abstract

4-nitrophenol is a serious environmental pollutant due to its carcinogenic, mutagenic, and teratogenic properties, posing serious risks to aquatic life, plants, and humans even at very low concentrations. In the current work a simple, inexpensive, and ecologically appropriate approach for generating palladium nanoparticles (Pd-NPs) from palladium chloride and their potential for the reduction of 4-nitrophenol have been investigated. This method employs a non-toxic aqueous extract obtained from the aerial portion of Roylea cinerea, which functions as both a reducing and stabilizing agent. The Pd-NPs synthesis was confirmed through UV–vis spectroscopy, and were further characterized by techniques like FT-IR, SEM, EDX, and XRD analysis. The biosynthesized Pd-NPs had a spherical shape with diameters ranging from 20 to 30 nm. The presence of palladium in the Pd-NPs was confirmed by EDX analysis. The available functional groups on the surface of Pd-NPs were determined through FTIR analysis. Pd-NPs demonstrated catalytic efficacy in both Sonogashira and Suzuki coupling processes, as measured by UV–vis spectrophotometry during nitrophenol reduction. The findings demonstrate that the Pd-NPs exhibited significant catalytic efficiency, achieving the degradation of over 95 % of 4-nitrophenol within a 16-min timeframe. Following the catalytic reaction, the catalyst was effortlessly recovered through centrifugation, demonstrating its ability to undergo multiple catalytic cycles without a significant loss of activity (>90 % after five cycles).