Synthesis and Characterization of Pd Nanoparticles by Laser Ablation in Water Using Nanosecond Laser

Colloidal solutions of Pd nanoparticles were produced by laser ablation of solids in liquids (LASL) technique. Two different lasers operating at 1064 and 532 nm of wavelength to ablate a Pd foil submerged in water were used. The properties of the obtained nanoparticles were studied and the influence of the wavelength on the nanoparticle size was discussed. The nanoparticles formation mechanism is discussed and compared with the results obtained in previous work using continuous wave (CW) and long pulses lasers. The obtained nanoparticles were characterized by means of transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and UV/VIS absorption spectroscopy. The obtained nanoparticles consisted of crystalline Pd nanoparticles with rounded shape and strong tendency to agglomeration. The size distribution of the nanoparticle range from few nanometers to 40 nm together with the presence of occasional large particles when the infrarred (IR) laser was used.