Simple pre-treatment by low-level oxygen plasma activates screen-printed carbon electrode: Potential for mass production

Screen-printed carbon electrode (SPCE) contains excessive binder which covers the graphite electrode to affect SPCE performance. Oxygen plasma treatment has the potential to remove the binder effectively to enhance electrochemical activity. However, neither the mechanism of this enhancement nor the impact on reference and auxiliary electrodes is clear. To this end, SPCEs were subject to plasma treatment as a whole, followed by scanning electron microcopy and X-ray photoelectron spectroscopy assays to investigate topological and chemical variations on the SPCE surface. Electrochemical performance of plasma-treated SPCEs is dependent primarily on the plasma power, not the duration of treatment. Lower power (50 - 100 W) facilitated binder removal and exposure of both the edge and micro-edge planes of the graphite grains, resulting in significantly improved electrochemical sensitivity of SPCE. However, higher power (200 - 300 W) triggered a coating process due to re-deposition of etched binder to cover up both the basal and edge planes of the graphite grains, resulting in poorer performance of SPCE. Under optimized treatment conditions, SPCE displayed excellent intra-electrode repeatability, inter-electrode reproducibility, and improved electroactivity with no known negative impact from the oxidation of silver reference electrode, demonstrating that oxygen plasma pre-treatment holds potential for mass production of SPCE.

Automated summary

The study shows that oxygen plasma treatment can effectively remove the binder in SPCE, enhancing its electrochemical activity. Optimized treatment conditions significantly improve the electrochemical sensitivity of SPCE, while higher power treatment leads to a decrease in performance.