Compact and accurate approximants to determine the transient current at the disc electrode under different boundary conditions

An investigation into the transient current at the disc electrode is presented in this paper. Two boundary conditions on the disc are considered: the disc has a uniform concentration over its area, and the disc exhibits a charge transfer (irreversible reaction). The principle of scale analysis is used to determine both the short and long time asymptotic behaviour. Compact and accurate expressions are proposed to evaluate the transient current regardless of the time scale. A relevant correlation method is used for this purpose. The results show an excellent agreement with available works for the uniform concentration and the charge transfer cases respectively.