Nanoplates and nanostars of β-PbO formed at the air/water interface

Nanoparticles with different shapes were prepared at the air/water interface via hydrolysis of Pb2+ ions under Langmuir films of poly(N-vinylcarbazole) (PVK) at 30–50 °C. It was found that round or irregular nanoparticles with the size of several to several tens of nanometers were formed when the PbCl2 aqueous solution with the concentration of 1 × 10−3 mol L−1 was used as subphase, while single-crystalline quasi-hexagonal nanoplates, nanostars and dendrites with the size of several hundreds of nanometers were obtained when the subphase concentration was 1 × 10−4 mol L−1. Analysis on the selective-area electron diffraction (SAED) patterns revealed that the formed nanoparticles are β-PbO. The formation of the nanostructures should be attributed to the formation and dehydration of lead hydroxide, diffuse-limited growth and aggregation of nanoparticles at the air/water interface.

Figure optionsDownload as PowerPoint slideResearch highlights▶ PVK forms monolayers at the interface of air/aqueous solution of PbCl2. ▶ Pb2+ ions enriches in the interfacial phase. ▶ Pb2+ ions hydrolyze to form Pb(OH)2 that dehydrate to form β-PbO. ▶ Nanoplates, nanostars and nanodendrites of PbO nucleate and grow at the interface. ▶ These nanoparticles are single nanocrystals.