Peanut skin extract facilitated phytofabrication of PdNPs for dual catalytic applications: Suzuki–Miyaura coupling and methylene blue reduction

Abstract

The present manuscript describes a novel phyto-fabrication of palladium nanoparticles (PdNPs) using an environmentally friendly/bio-genic method. 0.05 g mL⁻¹ peanut skin extract (PSE) was used as a non-toxic reducing, stabilizing and capping agent. The phyto-constituents of peanut skin, such as polyphenols, anthocyanin, flavonoids, etc., are anticipated to be involved in the reduction and stabilization/capping of PSE@PdNPs. The formation of PdNPs was confirmed by ultraviolet visible (UV/visible) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The role of phytochemicals was verified by FTIR. The XRD pattern confirms the crystals with face centred cubic (FCC) structure, an average grain size of ∼5.421 nm and mechanical behaviour [average strain (ε = 0.00647), dislocation density (δ = 0.0412 nm⁻²)]. The TEM images reveal the granular-shaped PSE@PdNPs with an average diameter of 5–8 nm and an FCC crystal lattice. PSE@PdNPs effectively catalysed the Suzuki–Miyaura (S–M) cross-coupling (C-C) reactions in aqueous medium at room temperature (RT). PSE@PdNPs offer an excellent yield (∼98%) of the coupled products only in ∼40 min in the presence of air/moisture. The hot-filtration test confirms the negligible leaching with the heterogeneous nature of the catalyst. The catalytic performance of the PSE@PdNPs is retained in up to five successive reusability runs. In addition, PSE@PdNPs superbly degraded methylene blue (MB) dye (∼97.5%) in the presence of NaBH₄ in ∼50 seconds following pseudo-first-order reaction kinetics with a rate constant (k) of 6.70 × 10⁻² ± 0.003 s⁻¹ at RT. The present approach provides a dual advantage of eco-friendliness for production and heterogeneous catalysis (MB degradation and S–M coupling) for environmental sustainability.