Laser ablation synthesis in solution and size manipulation of noble metal nanoparticles

Abstract

In the past years, laser ablation synthesis in solution (LASiS) emerged as a reliable alternative to traditional chemical reduction methods for obtaining noble metal nanoparticles (NMNp). LASiS is a "green" technique for the synthesis of stable NMNp in water or in organic solvents, which does not need stabilizing molecules or other chemicals. The so obtained NMNp are highly available for further functionalization or can be used wherever unprotected metal nanoparticles are desired. Surface functionalization of NMNp can be monitored in real time by UV-visible spectroscopy of the plasmon resonance. However LASiS has some limitations in the size control of NMNp, which can be overcome by "chemical free" laser treatments of NMNp. In this paper we provide an overview of LASiS, size manipulation by laser irradiation and functionalization of NMNp, with special care in pointing out some of the main issues about this research area.

Coexistence of plasmonic and magnetic properties in Au89Fe11 nanoalloys

“…In LASiS, a difference between the stoichiometry of alloy nanoparticles and the original alloy target is observed when the two elements in the alloy have different reactivities or different vaporization heats. 48,53,54 Here, the vaporization heats of gold and iron are similar (324 and 340 kJ mol À1 , respectively), but iron can react with oxygen that is dissolved in non-deaerated solvents, as reported for instance during LASiS of NiFe NPs. 55 Transmission electron microscopy (TEM) images of the AuFeNP solution just aer LASiS but prior to the addition of EDTA/PEG indicated the presence of iron oxide and amorphous phases ( Fig.…”

“…Using this top-down approach, [48][49][50][51][52] we were able to overcome the thermodynamic limitations to the room-temperature formation of Au-Fe alloys. 48,53 The formation of nanoparticles was immediately visible from the reddish color of the solution, which became purple aer a few hours due to particle aggregation. Aer LASiS, an aqueous solution containing disodium ethylenediaminetetraacetic acid (EDTA) and thiolated polyethyleneglycol (PEG) was added to the AuFeNP dispersion in ethanol and the solution was kept at 60 C for 1 hour (Fig.…”

“…Planar defects in fcc metals are usually associated with internal stresses due to rapid cooling, 59 and are typical of LASiS. 48,53 We used energy-ltered TEM (EFTEM) to gather additional information on the elemental distribution of Au and Fe in individual PEG-AuFeNPs. We performed elemental mapping on ve nanoparticles with sizes between 15 and 50 nm by selecting the Au N-edge (83 eV) and the Fe L-edge (708 eV) respectively ( Fig.…”

Synthesis, Functionalization, and Design of Magnetic Nanoparticles for Theranostic Applications

“…[33] Top-down options are preferred in industry because they are simpler, less expensive, and easy to scale up the production. Although it is a viable green technique and requires limited manual operation, [34] particles functionalization will be more problematic and the resultant NPs through these inexpensive routes will be in a wide distribution of size and shapes [35] which directly limit their utilization for biological applications. On the other hand, bottom up techniques (also known as wet chemistry routes) refer to the chemical synthesis of nanoparticles wherein the primary nucleation of nanomaterials followed by growth and aggregation will finally result in desired nanoparticles with specific size and shapes.…”

Structural Modifications of KrF Excimer Laser-Ablated Zirconium Correlated to the Surface and Mechanical Properties

“…The plasma-induced pressure will lead to an additional temperature increase of the laser-induced plasma. Therefore, the shock wave generated by the expansion of laser-induced plasma, under confinement of liquid pushes the laser-induced plasma into a thermodynamic state of the higher temperature, higher pressure and higher density, and the plume species react with surrounding liquid molecules in this extreme state to form various compounds like ZrO 2 (tetragonal and monoclinic), Zr 3 O, ZrH, and ZrH 2 [37].…”