Experimental examination of the room temperature hydrodynamics and electrochemical current‐voltage behaviour of the Bi‐terminated vibrating wire electrode

Abstract

AbstractAn experimental study was made of the room temperature hydrodynamics and current‐voltage (I‐V) behaviour of a bi‐terminated transverse oscillating resonant electrode using an adaptation of the electromagnetically‐driven vibrating wire technique recently developed for precise viscosity measurements of cryogenic fluids. For argon, nitrogen, as well as dilute electrolytes, the shapes of the in‐phase and quadrature resonance lines agreed with lines obtained by computer simulation. Although such peaks exhibited shorter heights than predicted (probably due to dispersion or some energy loss to the end terminations), observed peak areas agreed with theory. Use of either 50‐μm diameter platinum or tungsten wires as working electrodes in three‐electrode voltammetry yielded quite well‐defined I‐V curves for reduction of dilute ferricyanide and iodate as test systems, with Fe(CN)6−3 exhibiting near‐Nernstian reversibility at the tungsten wire. Well‐shaped I‐V curves were also obtained for lead (II) reduction on oxide‐free platinum. Resonant platinum wires clad with lead films produced by controlled potential deposition yielded, as expected, an advantageous negative shift in potential for H+ reduction. Because the mechanical properties of soft or low tensile strength metals deny their direct use as resonant electrodes, clad wires, on the other hand, should enable electrochemical, corrosion, and surface studies of such materials to be accomplished under rather precisely controlled conditions.