Synthesis of silver nanoparticles supported on silica aerogel using gamma radiolysis

摘要

Silver clusters on SiO2 support have been synthesized using 60Co gamma radiation.The irradiation of Ag+ in aqueous suspension of SiO2 in the presence of 0.2mol dm-3 isopropanol resulted in the formation of yellow suspension.The absorption spectrum showed a band at 408 nm corresponding to typical characteristic surface plasmon resonance of Ag nanoparticles.The effect of Ag+ concentration on the formation of Ag cluster indicated that the size of Ag clusters vary with Ag+ concentration,which was varied from 4 x 10-4 to 5 x 10-3mol dm-3.The results showed that Ag clusters are stable in the pH range of 2-9 and start agglomerating in the alkaline region at pH above 9.The effect of radiation dose rate and ratio of Ag+/SiO2 on the formation of Ag clusters have also been investigated.The prepared clusters have been characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM),which showed the particle size of Ag clusters to be in the range of 10-20 nm.