Convenient, rapid synthesis of silver nanocubes and nanowires via a microwave-assisted polyol method

Silver nanostructures have been synthesized via a microwave-assisted polyol method by adding sodium sulfide (Na2S) into the solution. An interesting morphology evolution can be observed by adjusting the concentration of Na2S and the heating power. It is found that the ideal concentration of Na2S is 31.25-500 mu M for the fast reduction of Ag+ at 300 W under optimal conditions for producing monodispersed silver nanocubes. When the heating power is increased to 400 W, 62.5-250 mu M is the ideal concentration of Na2S for the synthesis of silver nanocubes. On increasing the concentration of Na2S (>500 mu M), a mixture of silver nanowires, nanocubes, bipyramids, and irregular/quasispherical particles is synthesized at 300 and 400 W. In particular, an increase in the concentration of Na2S to 750 mu M at 400 W leads to the production of a quantity of silver nanowires. In addition, silver nanocubes with controllable sizes can be obtained by changing the concentration of Na2S and the heating power. Compared to traditional wet-chemical methods, this method has the advantage of a marked decrease in reaction time to 3.5 min. Finally, our work provides a simple strategy for fabricating silver nanostructures with controllable morphologies and sizes.