Beet juice utilization: Expeditious green synthesis of noble metal nanoparticles (Ag, Au, Pt, and Pd) using microwaves

Metal nanoparticles of Ag, Au, Pt, and Pd were prepared in aqueous solutions via a rapid microwave-assisted green method using beet juice, an abundant sugar-rich agricultural product, which served as both a reducing and a capping reagent. The Ag nanoparticles with capping prepared using beet juice exhibit higher catalytic activity and durability than those prepared using NaBH ₄ for the transformation of 4-nitrophenol to 4-aminophenol.