Silver nanoparticles have attracted much attention as a subject of investigation due to their well-known properties, such as high electrical and thermal conductivity, catalytic activity, localized surface plasmon resonances, antibacterial and antifungal effects, etc. They are used in many different areas, medicine, photovoltaic solar cells, industrial applications, and scientific investigation, etc. The size as well as the shape is very important for certain applications.
There are different techniques for producing Ag nanoparticles using chemical, physical and biological routes. Each method presents its own disadvantages and restrictions, being the most used chemical.
In the present work, laser-assisted methods such as ablation of solids in liquid phase (LASL) and laser ablation of solids in open air (LASOA) have been utilized to prevent the presence of contamination and impurities in obtained products. These methods are good alternatives to chemical reduction, especially when biological applications are taken into account. A pulsed Nd:YVO4 laser and a CW Yb fiber laser were used in this work. The influence of different processing parameters on nanoparticle shape, size and crystalline phase has been studied.
The obtained particles consisted of pure Ag nanoparticles showing rounded shape and uniform size distribution. Crystalline phases, morphology and optical properties of the obtained colloidal nanoparticles were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and UV/VIS absorption spectroscopy. The obtained nanoparticles consisted of Ag nanoparticles showing rounded shape with diameters ranging from few to 50 nm.