Plasma Electrochemistry in 1-Butyl-3-methylimidazolium dicyanamide: Copper Nanoparticles from CuCl and CuCl2

We report on the reaction of CuCl and CuCl2, each dissolved in 1-butyl-3-methylimidazolium dicyanamide ([BMIm]dca), with a glow discharge argon plasma. The interaction of the plasma with the solutions exhibits a strong reaction with gas evolution and the growth of copper nanoparticles. The particle size was determined with transmission electron microscopy (from the particle/ionic liquid, IL solution). The chemical composition was investigated by ex situ X-ray photoelectron spectroscopy (XPS). We found that the mean diameter of the copper particles produced in CuCl/[BMIrr]dca and CuCl2/[BMIm]dca was in the same order of magnitude (between 2 and 10 nm). Despite the strong reaction we found no hints for IL degradation products in the liquids with infrared spectroscopy. XPS showed that ex situ treatment of the particles leads to the formation of CuO.