Helium-assisted, solvent-free electro-activation of 3D printed conductive carbon-polylactide electrodes by pulsed laser ablation

Abstract

Fused filament fabrication is one of the most rapidly developing 3D printing techniques, with numerous applications, including in the field of applied electrochemistry. Here, the utilisation of conductive carbon black polylactic acid (CB-PLA) for 3D printouts is the most promising. To use CB-PLA as an electrode material, an activation process must be performed, removing the polymer matrix and uncovering the electrically conductive filler. We present a novel, alternative approach towards CB-PLA activation with Nd:YAG (λ = 1064 nm) laser ablation. We present and discuss the activation efficiency based on various laser source operating conditions, and the gas matrix. The XPS, contact angle, and Raman analyses were performed for evaluation of the surface chemistry and to discuss the mechanism of the activation process. The ablation process carried out in an inert gas matrix (helium) delivers a relatively high electrochemically active surface area of the CB-PLA electrode, while the resultant charge transfer process is hindered when activated in the air plausibly due to the formation of thermally induced oxide layers. The electroanalytical performance of laser-treated CB-PLA in a He atmosphere was confirmed through caffeine detection, offering detection limits of 0.49 and 0.40 μM (S/N = 3) based on CV and DPV studies, respectively.