Green Preparation of Ultra-fine Silver Particles in Ionic Liquid

A room-temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4), was synthesized with two-step method and its structure was characterized by IR, H-NMR. Putting p-benzenediol and AgNO3 ethanol solution into [bmim] BF4, ultra-fine silver powder were prepared successfully in this paper. The effects of the temperature and material mol ratio of AgNO3 and p-benzenediol on the shape of products were studied. The products were characterized by XRD, SEM, IR and TEM. The results showed that the particle size of silver was much smaller and in the range of nanometers, and had narrowly, uniform distribution, which indicates that the synthesis method using ionic liquid, is the better "green" and "environment friendly" method to prepare ultra-fine silver powder.