Inherent electrochemistry and charge transfer properties of few-layered two-dimensional Ti₃C₂T_x MXene

We report the effect of the Ti3C2Tx MXene flake thickness on its inherent electrochemistry and heterogeneous charge transfer characteristics. It is shown that Ti3C2Tx undergoes irreversible oxidation in a positive potential window, which strongly depends on the flake thickness and pH of the electrolyte. Few-layered Ti3C2Tx exhibits faster electron transfer kinetics (k0 = 0.09533 cm s-1) with a [Fe(CN)6]4-/3- redox mediator compared to multi-layered Ti3C2Tx (k0 = 0.00503 cm s-1). In addition, the few-layered free standing Ti3C2Tx film electrode remains intact after enduring irreversible oxidation.