Copper Nanoparticles with a Tunable Size: Implications for Plasmonic Catalysis

An access to copper(0) nanoparticles (CuNPs) from readily available organocopper reagents is reported. This original amine-free methodology proves to be practical, fast, and highly reproducible. It yields spherical CuNPs with an excellent control of their size and shape. These CuNPs are fully characterized by electronic microscopy (transmission electron microscopy and high-resolution TEM), X-ray photoelectron spectroscopy, X-ray diffraction, and UV-vis spectroscopy. The size of the synthesized nanoparticles is in a size range of 5-9 nm. The reactional pathway is studied and shows a two-step process implying the formation of a primitive bulk composed of spheroid CuNPs followed by a reorganization step induced by a thiol additive and leading to the final NPs. The robustness of this convenient protocol enables decigram scale synthesis of CuNPs without altering their size and morphology, which makes it a preparative method of choice for their synthesis. This protocol allows the rational design of future copper-based catalysts. The importance of controlling several physicochemical parameters such as size, composition, and shape in metal nanomaterials is indeed widely reported. The results presented here offer many prospects for the rapidly developing field of copper plasmonic catalysis.