Shape-controlled synthesis for silver: Triangular/hexagonal nanoplates, chain-like nanoplate assemblies, and nanobelts

Individual triangular/hexagonal nanoplates, chain-like nanoplate assemblies, and nanobelts in the case of silver were selectively synthesized using N,N-dimethylformamide (DMF) in the presence of poly (vinyl pyrrolidone) (PVP). The molar ratio of AgNO3/PVP, concentration of AgNO3, temperature, and process time were crucial factors in determining the morphologies of the final products. Based on the experimental results, it was concluded that the products were favorable to form individual nanoplates because of the strong interaction between PVP and Ag+, and the outline of the nanoplates was controlled by the ratio of AgNO3 and PVP. The formation of novel chain-like nanoplate assemblies could be explained by the secondary growth of the nanocrystals. If the reaction continuously lasted for another 7 h, the chain-like assemblies could transform into nanobelts with width of 40∼100 nm and the length of several micrometers.