Porous, Ultrathin PtAgBiTe Nanosheets for Direct Hydrazine Hydrate Fuel Cell Devices

Abstract Ultrathin 2D nanomaterials have attracted extensive attention due to their fascinating applications in sustainable and clean‐energy‐related devices, but obtaining ultrathin 2D multimetallic polycrystalline structures with large lateral dimensions remains a challenge. In this study, ultrathin 2D porous PtAgBiTe and PtBiTe polycrystalline nanosheets (PNSs) are obtained via a visible‐light‐photoinduced Bi₂Te₃‐nanosheet‐mediated route. The PtAgBiTe PNSs are assembled by sub‐5 nm grains with widths beyond 700 nm. Strain and ligand effects originating from the porous, curly polycrystalline structure endow the PtAgBiTe PNSs with robust hydrazine hydrate oxidation reaction activity. Theoretical research demonstrates that the modified Pt activates the N–H bonds in N₂H₄ during the reaction, and strong hybridization between Pt‐5d and N‐2p facilitates dehydrogenation while reducing energy consumption. The peak power densities of the PtAgBiTe PNSs in actual hydrazine‐O₂/air fuel cell devices are boosted to 532.9/315.9 mW cm⁻², while those of the commercial Pt/C are 394.7/157.9 mW cm⁻². This work provides a strategy not only for preparing ultrathin multimetallic PNSs but also for finding promising electrocatalysts for actual hydrazine fuel cells.