Electrochemical quartz microbalance with working mercury electrode for quantitative studies of monolayer adsorption Original Research Article

The preparation and use of electrochemical quartz microbalance (EQCM) for quantitative measurement of adsorbed mass is described. The thickness of mercury film cannot exceed 20 nm. Best results are achieved when mercury is deposited on platinum at negative potentials, from −0.4 to −0.5 V versus Ag | AgCl | KClsat. At greater thickness, transformation of mercury films into less densely populated and larger droplets can be triggered by various surface perturbations. This leads to a deviation from linearity in the dependence of added mass on the frequency change. The suitability of a mercury coated EQCM has been demonstrated by measurements in lead(II) and thallium(I) containing solutions.