Integral equation theory for the electrode-electrolyte interface with the central force water model. Results for an aqueous solution of sodium chloride

Abstract

The structure of an aqueous solution of sodium chloride at a planar elec- at the uncharged and charged electrode. The rather rigid ice-like water structure found previously at the neutral surface strongly repels the ions. Steric interactions between the differently sized ions and the ice-like water structure dominates the ionic distribution near the electrode. This model electrolyte also responds differently to opposite charges on the electrode. We found the asymmetry in the differential capacitance curve entirely determined by the response of the interfacial water structure.

The influence of image interactions on the structure of water and electrolytes in front of a metal surface

“…Inspite of this disorder this structure apparently determines strongly the approach of ions towards the surface. 12 Also the area density of oxygen in the first double layer, O ϭ0.1 Å Ϫ2 , as obtained from integration of the density profile in Fig. 3͑a͒, is found to be close to the value O ϭ0.11 Å Ϫ2 expected for the perfect ice layer.…”

“…8,9 These interactions do not contain screening of the polarization due to neighboring particles, but usually bind the oxygen of water so strongly ͑40.7 kJ/molϭ0.42 eV/molecule at the on top site͒ that the water structure is dominated by this fact. We have seen recently that the central force model of water near a hard wall forms an icelike structure solely due to hydrogen-bonding 11,12 analog to the simulation results for an ST2-model 13 and a point multipole model. 14 We are now interested how sensitive this structure reacts to changes of the wall interaction.…”

“…As in our previous calculations 11,12 we will derive the water structure near the interface by calculating the particle densities via the Wertheim-Lovett-Mou-Buff ͑WLMB͒ equation…”

“…A calculation with added Na ϩ Cl Ϫ ions showed again this capacitance minimum due to the water structure. 12 When we saw the changed water structure Fig. 4͑b͒ at high positive electrode charges 18 we expected a high polarizability of the interface region at electric fields, where the transition from structure Fig.…”

The Role of Sodium Sulfate Supporting Electrolyte in Ammonium Transport and Reduction at Interface Between Platinum Cathode and Solution

“…competitively reduced the effective current efficiency of NH 4 + and produced electrode overpotential at a fixed electric current [18][19][20][21]. Therefore, the influences of Na + on the behaviors of mass transportation in the EDL cannot be ignored when Na 2 SO 4 is used as the supporting electrolyte.…”