3D printed polylactic acid/carbon black electrodes with nearly ideal electrochemical behaviour

Abstract

In recent years electrochemistry has joined the revolution in 3D printing. Not only electrochemical cells but also conductive electrodes may be now conveniently and inexpensively manufactured directly in electrochemical laboratories. However, 3D printed electrodes typically suffer from considerable intrinsic kinetic barrier that manifests itself as increased separation of faradaic peaks in cyclic voltammograms. In this work we employ fused deposition modelling 3D printing to manufacture electrodes from a conductive polylactic acid (PLA)/carbon black composite filament. We further activate electrodes by a simple electrochemical anodic procedure. Cyclic voltammograms employing Ru(acac)3 as the electroactive probe show the faradaic peak separation values between 80 and 85 mV which is superior to any value reported for a 3D printed PLA-based electrode so far. Furthermore, comparison of experimentally obtained faradaic peak current values with those calculated theoretically shows that the relative effective surface area of electrodes approaches unity. Our work clearly demonstrates that 3D printed electrodes may reach characteristics well comparable to those obtained at conventional metallic or carbon electrodes.