The interaction of an intense femtosecond laser pulse with a neat liquid solvent has been known to produce a number of highly reactive species that are useful to induce photochemical reduction in the solution through the multiphoton excitation and ionization of solvent molecules. We named the phenomena as a femtosecond laser induced photochemical reaction (FLIP). High reactive species such as solvated electron and hydrogen radicals generated in FLIP process have a strong reducing power to reduce metal ions present in the solution. In this way, zero valence metal atoms are expected to precipitate resulted in the nanoparticles formation. Furthermore, when two or more metal precursors with different reduction potential are involved in the reduction process, the formation of homogenous alloy can be possibly generated, even for the immiscible system in the thermodynamic phase diagram. Moreover, nanostructure on a substrate can also be generated if the laser was focused and scanned over the interface between liquid and the substrate. Unlike its sister technology, i.e. pulse laser ablation in liquid (PLAL), FLIP has not been explored thoroughly, opening many more questions to find its answer.
In this seminar, I will deliver the fundamental aspects and the recent advances of this research in two main topics: (1) a synthesis of pure, binary and ternary system of gold (Au), silver (Ag) and platinum (Pt) noble metal nanoparticles using FLIP without pre-added reducing chemicals, and (2) nanostructure fabrication using FLIP with a radial polarized beam of MHz-repetition-rate femtosecond laser. In general, interesting findings and advances about the synthesis of pure and alloyed noble metal nanoparticles and nanostructures have been revealed, mainly by exploiting the interaction of femtosecond laser pulses with liquid. This route provides an easily and reproducible synthetic approach, that is applicable as an alternative for the established methods.