Functionalized Ionic Liquids Sputter Decorated with Pd Nanoparticles

The fabrication of surface clean palladium nanoparticles of 3–4 nm was accomplished in imidazolium-based functionalized ionic liquids (ILs) having methoxy, cyano, and thio groups by magnetron sputtering deposition. The size of the NPs was strongly dependent on the surface composition and/or organisation of the ILs. The NP growth apparently occurred preferentially in the bulk of the fluids, whereas nucleation apparently occurred preferentially at the IL surface. Smaller NPs were detected close to the methoxy containing IL surface and were covered by at least one layer of IL ion pairs, as revealed by high-sensitivity low-energy ion scattering (HS-LEIS) measurements.