LAUSR

Ionic liquids are considered to be versatile solvents and mediums in which certain chemical reactions and physical processes can take place. Here we report how ionic liquids acting as a collection medium for sputtered nanoparticles/quantum dots are not necessarily inert and stable during deposition and may lead to possible misinterpretation of the nanoparticle optical properties. By depositing Si nanoparticles in 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl sulfonyl)imide ([C4mpyrr][Tf2N]), we demonstrated that the color change observed upon sputtering was related to the electrochemical decomposition of the [C4mpyrr] cation and not to the presence of Si nanoparticles. Furthermore, a gelation of the medium is observed and is proposed to occur through interaction between the silicon nanoparticles and the ionic liquid and is facilitated by the presence of water.