Phytochemical synthesis of PdNPs utilizing Stellaria media/Chick weed: A Chinese medicinal herb for its antioxidant and catalytic application

[Display omitted] •Phytochemical synthesis of S. sativa-capped Palladium nanoparticles.•Characterization of S. sativa-capped Palladium nanoparticles using various advanced techniques FE-SEM, TEM, EDS, XRD.•Potential biomedical application of the synthesized S. sativa-capped Palladium nanoparticles as an antioxidant.•Catalytic reduction of organic pullutant. In the present paper, fast, eco-friendly, nontoxic, biosynthesis of Palladium nanoparticles (PdNPs) mediated via Stellaria media (SM)/ Chick weed (CW) leaf extract is presented. The physicochemical, atomic composition, crystal structure, morphology (shape and size) of synthesized PdNPs mediated via CWleaf extract were characterized utilising different characterization techniques: Ultraviolet–visible (UV–vis), Fourier transform infrared (FT-IR), Energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and Transmission electron microscopy (TEM). Absorption analysis validates the formation of PdNPs by the complete absence of absorption peak at 417 nm on nanoparticles formulation. Structural and functional group analysis suggests that the polyphenolic compound which is a secondary metabolite is the phytochemical which takes part in the reduction of Pd+2 ions into Pd0. Crystallite structure analysis confirms the formation of PdNPs having particle size 13.2 nm with face centered cubic (fcc) lattice. Morphological and particle size of the prepared PdNPs confirmed that the synthesized PdNPs are monodisperse, spherical and in the range of 8.69 ± 0.5 nm. The synthesized biogenic PdNPs were then subjected to two different applications: catalytic and anti-oxidant applications utilising sodium borohydride (NaBH4), para nitrophenol (PNP) and α, α-diphenyl-β-picrylhydrazyl (DPPH). Catalytic reduction reveals that the total time require for the complete reduction of 4-nitrophenol to 4-aminophenol in 18 minutes only. Whereas, scavenging activity of the biogenically synthesized PdNPs exhibits maximum antioxidant activity at 72 h with 86.98 %. The results from the recent finding suggest that, the prepared PdNPs are very small in size and can be utilized in biomedical application after clinical trials.