Self-assembly of Au–Pt core–shell nanoparticles for effective enhancement of methanol electrooxidation

Au–Pt core–shell nanoparticles (Au–Pt NPs) as an effective bimetallic electrocatalyst for methanol oxidation has been extensively explored. However, the conventional drop-coating method for fabricating Au–Pt NP electrodes did not fully exploit the small size of the NPs. Here, self-assembly of Au–Pt NPs into monolayer arrays is proposed as an alternative for the preparation of Au–Pt NP catalytic electrode to ensure the exposure of each NP to electrolyte. Under the optimized condition, the Pt mass activity of the Au–Pt monolayer array was ∼6 times better than that of the commercial Pt/C catalyst, and 3 times better than that of Au–Pt NP electrodes fabricated by a drop-coating method, indicating superior electrocatalytic activity.

► Au–Pt core–shell nanoparticles were assembled into a monolayer array simply by an interfacial assembly method.
► Au–Pt core–shell nanoparticle monolayer arrays showed better electrocatalytic activity for methanol electrooxidation than Au–Pt core–shell nanoparticle electrodes fabricated by a drop-coating method.
► The mass-activity of the optimized Au–Pt core–shell nanoparticle monolayer array was 6 times as good as that of the commercial Pt/C, exhibiting a superior electrocatalytic activity.