Bubble-Mediated Large-Scale Hierarchical Assembly of Ultrathin Pt Nanowire Network Monolayer at Gas/Liquid Interfaces

Extensive macroscaletwo-dimensional (2-D) platinum (Pt) nanowirenetwork (NWN) sheets are created through a hierarchical self-assemblyprocess with the aid of biomolecular ligands. The Pt NWN sheet isassembled from the attachment growth of 1.9 nm-sized 0-D nanocrystalsinto 1-D nanowires featuring a high density of grain boundaries, whichthen interconnect to form monolayer network structures extending intocentimeter-scale size. Further investigation into the formation mechanismreveals that the initial emergence of NWN sheets occurs at the gas/liquidinterfaces of the bubbles produced by sodium borohydride (NaBH4) during the synthesis process. Upon the rupture of thesebubbles, an exocytosis-like process releases the Pt NWN sheets atthe gas/liquid surface, which subsequently merge into a continuousmonolayer Pt NWN sheet. The Pt NWN sheets exhibit outstanding oxygenreduction reaction (ORR) activities, with specific and mass activities12.0 times and 21.2 times greater, respectively, than those of currentstate-of-the-art commercial Pt/C electrocatalysts.

Automated summary

Extensive 2-D platinum nanowire network (NWN) sheets are created through a hierarchical self-assembly process with the aid of biomolecular ligands. The Pt NWN sheet is assembled from the attachment growth of 1.9 nm-sized nanocrystals into nanowires featuring a high density of grain boundaries, which then interconnect to form monolayer network structures extending into centimeter-scale size. The Pt NWN sheets exhibit outstanding oxygen reduction reaction (ORR) activities, with specific and mass activities 12.0 times and 21.2 times greater than those of current state-of-the-art commercial Pt/C electrocatalysts.