The capacitance and electron transfer of 3D-printed graphene electrodes are dramatically influenced by the type of solvent used for pre-treatment

3D-printing (or additive manufacturing) is presently an emerging technology that promises to reshape traditional manufacturing processes. The electrochemistry field can certainly take advantage of this fabrication tool for sensing and energy-related applications. Polymer/graphene filaments commonly used for the fabrication of 3D-printed electrodes show poor electrochemistry in the native state, requiring post-fabrication activation procedures. In the present work, solvent activation of graphene/polymer-based 3D-printed electrodes was investigated, using both polar aprotic solvents (DMF and acetone) and polar protic solvents (EtOH, MeOH, and H2O). Differences were noted with respect to the weight loss and surface morphologies of the activated electrodes prior to their use, depending the solvent used. The electrodes activated in polar aprotic solvents exhibit a dramatic increase in heterogeneous electron transfer rate using the Fe(CN6)(4-/3-) redox couple. Moreover, the activation medium has a crucial influence on the electrochemical double layer. We wish to provide meaningful insight to researchers by comparing results obtained with 3D-printed electrodes fabricated from graphene/polymer filaments and drawing attention to the influence of the solvents used in their activation.