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Potential-sweep voltammetry—adsorption of chloranilic acid on a mercury electrode

1967; Elsevier BV; Volume: 15; Linguagem: Inglês

10.1016/0022-0728(67)85050-2

2590-2954

Sergio Roffia, Elena Vianello,

Analytical Chemistry and Sensors

The behaviour of chloranilic acid on mercury electrodes has been investigated by linear potential-sweep voltammetry. In very dilute solutions, a single adsorption peak appears. In more concentrated solutions, a second peak is observed which is diffusion-controlled. The amount of chloranilic acid adsorbed at the different concentrations has been determined by extrapolation, from the plots of the integrals of the current-potential curves versus the reciprocal of the square-root of potential-sweep rate. The maximum surface coverage thus derived is in very good agreement with the surface excess obtained from measurement of the mercury-solution interface tension using the drop-weight method. The results are consistent with the hypothesis of the formation of a monolayer of chloranilic acid with a flat orientation of the molecule with respect to the electrode surface.