Synthesis of Silver Nanoprisms in DMF

Polygonal (mainly triangular) silver nanoprisms were synthesized by boiling AgNO3 in N,N-dimethyl formamide, in the presence of poly(vinylpyrrolidone). Although during the synthesis, a mixture of nanoprisms and nanospheroids is formed, the latter can be removed through careful centrifugation. The UV−visible spectra of the nanoprisms display an intense in-plane dipolar plasmon resonance band, as well as weak bands for in-plane and out-of-plane quadrupolar resonances. The nanoprisms are also stable in other solvents, such as ethanol and water, and solvent exchange leads to strong shifts of the in-plane dipole plasmon band.