Acta Phys. -Chim. Sin. ›› 1991, Vol. 7 ›› Issue (05): 549-552.doi: 10.3866/PKU.WHXB19910507

• ARTICLE • Previous Articles     Next Articles

Statistical Mechanical Treatment of Adsorbed Monolayer at Electrode Solution Interface IV. The Inner Layer Differential Capacity of Silver Single Crystal Electrode in Aqueous Solution

Su Wen-Duan; Zhou Shao-Min; Zhou Xiao-Lin   

  1. Department of Chemistry, Xiamen Univeristy, Xiamen 361005; Computer Center, Xiamen University
  • Received:1990-04-16 Revised:1990-11-21 Published:1991-10-15
  • Contact: Su Wen-Duan

Abstract: Based on the model of dipole orientation distribution presented in previous paper, the monolayer adsorption isotherm for solvent molecules at the interface of solid me- tal electrode wsa derived. The dependence of inner-layer differential capacity(C_1) on the surface charge density(σ) was estimated by curve-fitting for Ag(111), Ag(100) and Ag(110)/aqueous solution interface. The calculated results are shown. In analyzing the fitting parameters obtained from this treatment, it was found that the water molecules would preferentially be strongly adsorped on the top sites of (111)-plane, but would be on the hollow site at (110)-or(100)-plane. The high values of the inner-layer differential capacity for silver single crystal electrodes were interpreted in terms of those effects, i.e., the thickness of adsorption monolayer was diminished due to water molecules stably adsorbed on the hollow site of crystal face, and the influence of the interaction between metal and water molecules or between dipole-dipole of adsorbed molecules on the variation of potential drop acrossed the inner-layer with the surface charge at electrode.

Key words: Electrode/Solution interface, Electrical double layer, Inner layer differential capacity, Ag(single crystal)/aqueous system