Chronoamperometric Determination of Diffusion Coefficients for Borohydride Anions in Sodium Hydroxide Solutions

Chronoamperometry is carried out with a Au disc electrode in alkaline sodium borohydride solutions of varying concentrations and temperatures. By selecting conditions for which the borohydride oxidation is controlled by diffusion, it was possible to deduce diffusion coefficients and activation energies for borohydride concentrations ranging from 0.03 M to 0.12 M, and temperatures ranging from 25 to 65 °C. The estimated parameters were compared with other values reported in the open literature.