Preparation of small size palladium nanoparticles by picosecond laser ablation and control of metal concentration in the colloid

E Giorgetti; P Marsili; S Cicchi; L Lascialfari; M Albiani; M Severi; S Caporali; M Muniz-Miranda; A Pistone; F Giammanco

doi:10.1016/j.jcis.2014.11.066

Preparation of small size palladium nanoparticles by picosecond laser ablation and control of metal concentration in the colloid

J Colloid Interface Sci. 2015 Mar 15:442:89-96. doi: 10.1016/j.jcis.2014.11.066. Epub 2014 Dec 4.

Authors

E Giorgetti¹, P Marsili², S Cicchi³, L Lascialfari⁴, M Albiani³, M Severi³, S Caporali⁵, M Muniz-Miranda³, A Pistone⁶, F Giammanco⁷

Affiliations

¹ Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy. Electronic address: emilia.giorgetti@fi.isc.cnr.it.
² Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy; Department of Physics "E. Fermi", University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy.
³ Department of Chemistry "Ugo Schiff", University of Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy.
⁴ Istituto dei Sistemi Complessi, Consiglio Nazionale delle Ricerche, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy; Department of Chemistry "Ugo Schiff", University of Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy.
⁵ Department of Chemistry "Ugo Schiff", University of Firenze, Via della Lastruccia 3, 50019 Sesto Fiorentino (FI), Italy; Consorzio INSTM, Via Giusti 9, 50123 Firenze, Italy.
⁶ Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, 98166 Messina, Italy.
⁷ Department of Physics "E. Fermi", University of Pisa, Largo Bruno Pontecorvo 3, 56127 Pisa, Italy.

PMID: 25521554
DOI: 10.1016/j.jcis.2014.11.066

Abstract

We assessed a method for the preparation of small, highly stable and unprotected Pd nanoparticles by picosecond laser ablation in 2-propanol. The nanoparticles can be extracted from 2-propanol by centrifugation and redispersed in water, where a strongly negative ζ-potential assures long term stability. The proposed procedure permits reduction of particle size down to 1.6nm and optimization of the Pd(0):Pd(II) ratio which, in the best cases, was of the order of 6:1. The increase of this ratio with ablation times has been correlated to the high temperature conversion of PdO to metallic Pd by a simple theoretical model. A study of the relationship between colloid absorption at 400nm and Pd concentration permitted the role of PdO in the determination of the UV-vis spectra to be clarified and the limits of the Mie theory for the evaluation of colloid concentration to be established. The absorption at 400nm can be used as a fast method to estimate the Pd content in the colloids, provided that a calibration of the ablation process is preliminarily performed.

Keywords: Laser ablation; Metal clusters; Pd nanoparticles; Pd oxides.