title: On the formation of anisotropic gold nanoparticles by sputtering onto a nitrile functionalised ionic liquid.
abstract: Sputtering deposition of gold onto the 1-(butyronitrile)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BCN)MI·N(Tf)(2) ionic liquid (IL) has generated colloidal and stable gold nanospheres (AuNS) and gold nanodisks (AuND) in a bimodal size distribution. Upon increasing the sputtering discharge voltage, three distinct phenomena were observed: (i) the mean diameter of both AuNS and AuND decreased; (ii) the population with lower diameters increased and (iii) the formation of AuND disappeared at voltages higher than 340 V. By dissolving the colloidal gold nanoparticles (AuNPs) in isopropanol and dropping the product onto carbon-coated Cu grids, 2D and 3D superlattices tended to be formed, as observed by transmission electron microscopy (TEM). Therefore, the formation of AuND is probably related to a strong interaction between sputtered Au atoms of low kinetic energy and the nitrile groups orientated to the vacuum phase of the IL surface, which drives the preferential anisotropic lateral growth.
authors: Laboratório de Filmes Finos e Fabricação de Nanoestruturas (L3Fnano), Instituto de Física, Av. Bento Gonçalves 9500, P.O. Box 15051, 91501-970, UFRGS, Porto Alegre, Brazil.
authors: Heberton
authors: H
authors: Wender
authors: Pedro
authors: P
authors: Migowski
authors: Adriano F
authors: AF
authors: Feil
authors: Luciane F
authors: LF
authors: de Oliveira
authors: Martin H G
authors: MH
authors: Prechtl
authors: Rafael
authors: R
authors: Leal
authors: Giovanna
authors: G
authors: Machado
authors: Sergio R
authors: SR
authors: Teixeira
authors: Jairton
authors: J
authors: Dupont