Activation of additively manufactured electrodes using methanol and ethanol solutions

The use of polymer additive manufacturing to produce electrodes is an increasingly popular area of electrochemical research. However, one downside of additively manufactured electrodes is the frequent need to remove polymer from the electrode surface to reveal a triple-phase boundary in order for improved electrode performance to be realized. A common way to achieve this, is surface activation via chronoamperometry within an aqueous sodium hydroxide solution. However, it has not been investigated whether the same activation can be carried out effectively in solutions of sodium hydroxide in simple alcohols. Therefore, in this work, we study the effect of performing common chronoamperometric additive manufacturing electrode activation methodologies in methanolic and ethanolic solutions of 0.05 M sodium hydroxide and compare these to activation carried out in standard aqueous solutions at concentrations of both 0.05 M and 0.5 M. We show that the alcoholic solutions are more effective in removing polymer from the additive manufacturing electrode surface, but that this does not lead to any improvement in electrode currents, and furthermore appears to hinder electron transfer kinetics at the additive manufacturing electrode surface, with the latter effect shown to be related to differences in the surface functionality of the exposed carbon black filler particles. As well as being interesting chemical experiments in their own right, these results may well be of interest to electrochemists who intend for their additive manufactured electrodes to be applied in these alcohols or indeed other non-aqueous solvents.