Synthesis of Ag nanoparticles with tunable sizes using N,N-dimethyl formamide

Ag nanoparticles (NPs) were fabricated using N,N-Dimethyl formamide (DMF) as a solvent and reducing agent together with polyvinyl pyrrolidone (PVP) through a solvothermal method. The position of surface plasmon resonance (SPR) band of as-prepared Ag NPs changed with the chain length of PVP and red shifted with increasing the molecular weight of PVP. The concentration of PVP and reaction time affected the position of absorption peaks. The selective adsorption of PVP on the {100} and {111} facets of Ag depended on the kinds of solvents, which determined the driving force of the growth process of nanostructures. For comparison, ethylene glycol, water, and ethanol was added serving as solvents in the presence of PVP. The result indicates that DMF is a vital factor to kinetically control the formation of Ag NPs. Therefore the favorable facets of Ag nanostructures are {111} facets in a DMF solution. Ag nanoplates together with nanowires were observed in the system of ethanol and water, respectively.