A study of adsorption kinetics of alkanethiol and alkanedithiol on gold using cyclic voltammetry

A study of the adsorption kinetics of 1-octanethiol and 1,8-octanedithiol has been carried out on gold electrode by cyclic voltammetry with different concentrations. Analysis of the kinetic data show that the adsorption kinetics of 1-octanethiol and 1,8-octanedithiol can be satisfactorily described by Diffusion controlled Langmuir(DCL) model, irrespective of concentration. The rate constants of 1-octanethiol and 1,8-octanedithiol are almost invariable at different concertrations, however, the fluctuant range of 1,8-octanedithiol is larger than that of octanethiol. The rate constants of other alkanethiol(n=12,14,16,18) are measured and tunneling parameter (β) is determined from these data.