The effect of active screen plasma treatment conditions on the growth and performance of Pt nanowire catalyst layer in DMFCs

• Gas diffusion layers (carbon paper) were treated by active screen plasma (ASP).
• The growth of Pt nanowire (NW) layer was improved on the ASP treated carbon paper.
• The Pt-NW grown on 120°C/10min ASP treated carbon paper showed the best performance.

Catalyst layers play an important role in direct methanol fuel cells (DMFCs), providing the reaction sites and catalysing the electrochemical reactions. For gas diffusion electrodes with Pt nanowires in-situ grown on gas diffusion layers (GDLs), the hydrophobic property of the GDL surface negatively affects the growth of the Pt nanowire catalysts, leading to the unsatisfied catalysis performance. In this work, the influence of active screen plasma (ASP) treatment temperature and duration on the growth of Pt nanowire catalyst layer was systemically studied. Single cell performance test with in-situ electrochemical surface area (ECSA) measurement were conducted to evaluate the catalysis performance of the Pt nanowire catalyst layer grown on the ASP treated carbon paper; scanning electron microscopy (SEM) was used to observe the surface morphology of the catalyst layer formed. Results revealed that the ASP treatment conducted at 120 °C for 10 min can effectively promote the growth of Pt nanowires on carbon paper gas diffusion layer, which exhibited the best catalysis performance.