Impact of water activity on double layer parameters at the mercury/chlorates(VII) interface in the presence of mixed adsorption layers of 6-mercaptopurine–Triton X-100

Adsorption mechanism of 6-mercaptopurine, 6-mercaptopurine–Triton X-100 on the mercury electrode surface from 2, 4 and to 6 mol dm−3 chlorates(VII) was studied as the function of adsorbate bulk concentration. The experimental data obtained from the measurements of differential capacity of the double layer were used, namely the measurements of zero charge potential and surface tension at the zero charge potential. In the case of mixed adsorption layer of 6-mercaptopurine–Triton X-100 domination of 6MP in adsorption equilibria formation as well as competitive adsorption between the 6-mercaptopurine–Triton X-100 molecules were found. Significant contribution of water molecules in the adsorption–desorption processes was also observed.