One-Pot Synthesis of Reactive Base Metal Nanoparticles in Multifunctional Pyridine

A pyridine-mediated, one-pot synthesis of Zn-0, Sn-0, V-0, and Mn-0 nanoparticles is presented for the first time. Herein, pyridine is multifunctional, serving as a solvent, a reducing agent, and a surface-stabilizing agent. All metals were obtained as crystalline, spherical nanoparticles with very small sizes of 5.5 +/- 0.6 nm (ZN(0)), 5.1 +/- 0.7 nm (Sn-0), 5.3 +/- 0.6 nm (V-0), and 6.9 +/- 0.8 nm (Mn-0). Simple metal chlorides (ZnCl2, SnCl2, VCl3, MnCl2.) were used as the starting materials and heated in pyridine (autoclave, 210-300 degrees C). In addition to detailed particle characterization (high-resolution transmission electron microscopy, scanning transmission electron microscopy, Fourier-transformed infrared (FT-IR), X-ray powder diffraction, elemental analysis), the mechanism of reaction was explored (MS, NMR, FT-IR), indicating pyridine as the reducing agent that was oxidized to 2,2'-bipyridine. As a reliable and simple synthesis strategy, the novel pyridine-mediated approach can be highly relevant to obtain high-purity base-metal nanoparticles, and as a next step, to address widespread applications such as surface finishing of steel, catalysis, high-power batteries, or hydrogen storage.