Plant-mediated synthesis of size-controllable Ni nanoparticles with alfalfa extract

A facile and eco-friendly method for the preparation of sub-10 nm Ni nanoparticles (Ni NPs) has been developed based on the bioreduction of aqueous Ni(II) precursors with alfalfa extract. The XRD and XPS characterization results indicated the face-centered-cubic and zero-valent of Ni NPs, respectively. The size of the crystalline Ni NPs could be simply tuned by adjusting the concentration of alfalfa extract and strongly depended on the bioreduction of Ni(II). The biomolecular analyses of the extract also showed that flavonoids and reducing sugars played important roles in the bioreduction of Ni(II).