Monte Carlo Simulations of Ag⁺and Ag in Aqueous Solution. Redox Potential of the Ag⁺/Ag Couple

Abstract

We have performed Monte Carlo simulations of the Ag+ cation and of the Ag atom in water. We have used the Kozack and Jordan polarizable water potential. The pairwise solute−water potentials and the three-body cation−water potential are based on MP2 calculations. We get for the hydration enthalpy of Ag+ the value −5.65 ± 0.15 eV, in good agreement with the experimental value: −5.5 ± 0.1 eV. For the ionization free energy of Ag, we have tested three available methods (thermodynamic perturbation, overlapping distribution, and self-consistent histograms methods) and found out that they yield very close results. The redox potential of the Ag+/Ag couple is estimated to be −2.3 V/NHE. Since our potentials include no empirical data, the agreement with the electrochemical value, −1.9 V/NHE, and the thermochemical value, −2.1 V/NHE, is satisfactory.

Molecular Dynamics Simulations of a Silver Atom in Water: Evidence for a Dipolar Excitonic State

“…The calculated hydration enthalpy was about 120 kcal=mol, while the experimental value is around 127 kcal=mol. The discrepancy found for the coordination number is inherent to our choice to limit ourselves to a very simple LJ two-body potential for the Ag =water interaction [8,9]. It has been shown, for example, that the inclusion of dipolar and quadrupolar polarizability of Ag greatly enhances the description of silver chloride [10].…”

Modeling of Structural, Energetic, and Dynamic Properties of Few‐Atom Silver Clusters Embedded in Polynucleotide Strands by Using Molecular Dynamics

“…The L–J curve fits the potential of Erkoç and Yilma satisfyingly, although a small deviation appears at short distance. In the absence of any experimental data, a g ( r ) value of Ag 0 to the O atom of water, that is, g (Ag + ⋅⋅⋅${{\rm{O}}_{{\rm{H}}_{\rm{2}} {\rm{O}}} }$ ), was compared with the theoretical results published by Dubois et al15 To compute the same g ( r ) value with the L–J parameters from the fit on the potential of Erkoç et al, a MD simulation was performed with these parameters for a single Ag 0 in a box of water with the Amber FF12 and the Dynamic module of Tinker 11. A cubic periodic box with a length of 31.35 Å was built that was comprised of one Ag 0 and 1024 water molecules.…”

Preparation and antibacterial activity of polyvinyl alcohol/regenerated silk fibroin composite fibers containing Ag nanoparticles

“…Ionization free energy of Ag and the redox potential of Ag þ /Ag couple could be given by three methods: thermodynamic perturbation, overlapping distribution, and self-consistent histograms. 33 And a large number of reports were available on synthesis of nanoparticles containing Ag by different methods such as chemicals, 32,[34][35][36] UV irradiation, 28,35,37 ultrasound, 38,39 prolonged reflux, 40 c-ray irradiation, 41 and a simple heat treatment. 28 The common oven heat treatment and UV irradiation treatment were safe, convenient and effectual.…”