title: Laser-Assisted Synthesis of Colloidal Ni/NiOxCore/Shell Nanoparticles in Water and Alcoholic Solvents.
abstract: The nanosecond-pulse laser-assisted generation of Ni/NiOxcore/shell nanoparticles (NPs) in water and alcoholic fluids can yield colloidal solutions without surfactants. The size distribution can be controlled by the nature of the alcohol, the number of laser pulses and the laser fluence. The incubation of the nickel target ablation in liquid contact shows a dependence on the carbon number of the respective alcohol. The laser-generated NPs consist of crystalline nickel cores with face-centred cubic patterns and stacking fault defects surrounded by nickel oxide shells. The solvent butanol, in contrast to ethanol and isopropanol, yields a narrow, nearly unimodal, size distribution. The majority of NPs have low size distributions, with medians in the range of 10-20 nm. These can be related to a metal ablation plume interacting with a supercritical liquid that decelerates the ejected material in a low-density metal-water mixing region. NPs in the range above 30 nm result in a minority distribution tail that strongly depends on the fluid nature, the pulse number and the fluence. This coarse NP set may be correlated with the rupture of a superheated molten-metal layer into larger entities.
authors.affiliation: Department of Physical Chemistry, University of Vienna, Währinger Strasse 42, A-1090, Vienna, Austria.
authors.forename: Niusha
authors.initials: N
authors.lastname: Lasemi
authors.affiliation: Department of Physical Chemistry, University of Vienna, Währinger Strasse 42, A-1090, Vienna, Austria.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Pacher
authors.affiliation: Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090, Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Rentenberger
authors.affiliation: Department of Physical Chemistry, University of Vienna, Währinger Strasse 42, A-1090, Vienna, Austria.
authors.forename: Oscar
authors.initials: O
authors.lastname: Bomatí-Miguel
authors.affiliation: Department of Physical Chemistry, University of Vienna, Währinger Strasse 42, A-1090, Vienna, Austria.
authors.forename: Wolfgang
authors.identifier: http://orcid.org/0000-0003-2772-2049
authors.initials: W
authors.lastname: Kautek
keywords: alcohols; colloids; laser chemistry; nanoparticles; nickel