Adsorption of polyvinylpyrrolidone on Ag surface and mechanism of selective growth of Ag nanostructures

Abstract:

To elucidate the mechanism of selective growth of Ag nanowires in capping agents, we investigated and the interaction between polyvinylpyrrolidone (PVP) molecules and various Ag crystal surfaces by first-principles calculations. The results show that PVP molecules severely affect the stability of Ag surfaces. Only Ag (200) and Ag (111) facets well maintain their structures upon the absorption of PVP molecules, suggesting their preferential growth in this capping agent. With the increase of PVP concentration, the binding of PVP molecules to the Ag (200) facet becomes stronger than that of Ag (111), which may facilitate the formation of Ag (200) nanostructure. The regulation mechanism of long-chain PVP molecules on Ag (200) nanostructures is mainly governed by the van der Waals force as well as the chemical bonding between ketone oxygen and Ag atoms.