An unusual non-Tafel dependence for electron transfer reactions in ionic liquids at large electrode polarisations: Fiction or reality?

We speculate about the existence of a square-root Tafel dependence for simple one stage anodic/cathodic electron transfer reactions in ionic liquids. In this dependence, the logarithm of the current depends linearly on the square-root of electrode potential. The modified law is a consequence of ion crowding in the electrical double layer at high charges of the electrode. It may be expected that this effect may be observed for slow reactions at large electrode polarisations, yet not triggering electrochemical decomposition of ionic liquids, and only if diffusion limitations on the transport of reactants are absent. (C) 2014 Elsevier B.V. All rights reserved.