Chemical strategies for tailoring properties of nanomaterials produced by pulsed laser interaction in liquid environments

Interactions of intense ultrashort laser pulses with liquid media and at solid-liquid interfaces produce plasmas with high densities of reactive chemical species that promote the formation of nanomaterials. This work discusses the current understanding of laser-induced chemical reactions in aqueous medium involving hydrated electrons and hydroxyl radicals, and the effects of chemical additives on these reactions. Two chemical strategies are presented for controlling the composition of the laser-induced plasma and nanomaterial properties. First, adding chemical scavengers of hydroxyl radicals will be shown to inhibit metal oxidation, enabling the synthesis of ligand-free Ag and Au-Ag alloy nanoparticles by reduction of Au and Ag salts. Second, ablating a silicon wafer in a solution containing two metal salts with different reduction potentials will be shown to enhance the deposition of the high-reduction potential metal onto the ablated silicon surface, producing high densities of metal nanostructures on silicon laser-induced periodic surface structures (LIPSS).