Mild synthesis of single-nanosized plasmonic copper nanoparticles and their catalytic reduction of methylene blue

Abstract

In this study, we report a mild synthesis of sub-10 nm Cu nanoparticles (NPs) in ethylene glycol (EG) at room temperature using l-ascorbic acid (AA) as the reducing agent in the presence of 1-amino-2-propanol (AMIP). To the best of our knowledge, this work is the first report of the room-temperature synthesis of sub-10 nm Cu NPs using a nontoxic reducing agent. The as-prepared colloidal suspension of Cu NPs exhibited surface plasmon resonance absorption at 515 nm. Transmission electron microscopy observations revealed well-dispersed spherical Cu NPs with an average particle size of 4.1 ± 0.8 nm. The use of AMIP as a ligand was found to be critical to producing sub-10 nm Cu NPs in EG under such mild conditions. Moreover, the sub-10 nm Cu NPs were an effective catalyst for the reversible methylene blue–AA reaction system.