Porous Pt/Ag nanoparticles with excellent multifunctional enzyme mimic activities and antibacterial effects

Enhancing the activity of Pt-based nanocatalysts is of great significance yet a challenge for the oxygen reduction reaction (ORR). In this work, a series of porous Pt/Ag nanoparticles (NPs) were fabricated from regular Pt_xAg_100–x (x = 25, 50, 75) octahedra by a facile and economical dealloying process. Remarkable enhancement in multiple enzyme-mimic activities related to ORR was observed for the dealloyed Pt₅₀Ag₅₀ (D-Pt₅₀Ag₅₀) NPs. This effect can be attributed to the resulting Pt-rich surface structure, increased surface area, and a synergistic effect of Pt and Ag atoms in the D-Pt₅₀Ag₅₀ NPs. Furthermore, the D-Pt₅₀Ag₅₀ NPs exerted excellent antibacterial effects on two model bacteria (gram-negative Escherichia coli and gram-positive Staphylococcus aureus). The present work represents a significant advance in the exploration of the relation between controllable synthesis of high-quality nanoalloys and their novel catalytic properties for various promising applications, including catalysts, biosensors, and biomedicine.