Continuous Flow Copper Laser Ablation Synthesis of Copper(I and II) Oxide Nanoparticles in Water

Copper(I) oxide (Cu₂O) nanoparticles (NPs) are selectively prepared in high yields under continuous flow in a vortex fluidic device (VFD), involving irradiation of a copper rod using a pulsed laser operating at 1064 nm and 600 mJ. The plasma plume generated inside a glass tube (20 mm O.D.), which is rapidly rotating (7.5 k rpm), reacts with the enclosed air in the microfluidic platform, with then high mass transfer of material into the dynamic thin film of water passing up the tube. The average size of the generated Cu₂ONPs is 14 nm, and they are converted to copper(II) oxide (CuO) nanoparticles with an average diameter of 11 nm by heating the as-prepared solution of Cu₂ONPs in air at 50 °C for 10 h.