Predicting the stability of capped metallic nanoparticles: Statistical Thermodynamic analysis

E.P.M. LEIVA

Niza

Conferencia; 61th Annual Meeting of the International Society of Electrochemistry; 2010

International Society of Electrochemistry

  The singular properties of metallic nanoparticles (NP) have awaked great interest in both the scientific and technological communities, and the size-dependence of their thermodynamic properties has been a hot topic of research in recent years. Currently, there are several methods to control the size of metallic NP. In those cases where nanoparticle growth is controlled by a redox system, the chemical identity of the redox species and/or the concentration ratio between the surfactant and the precursor agent [1] constitute the main variables. While much experimental effort has been devoted to understand this phenomenon, there is still no theoretical model available to unveil the role played by each of these variables on the final size of the NP. Following the framework established by Hill and Chamberlin [2] to analyze the extension of thermodynamics of small systems to metastable states and our own extension to electrochemical systems [3,4], we present here a statistical mechanical model aimed at establishing the role played by each of the following variables: nature of the surfactant, concentration of reactants, metallic nature of the NP, overpotential. A brief discussion on the model is made illustrating its application with computer simulations using realistic interatomic potentials. The thermodynamic stability of different structures is analyzed.