| 초록 |
This paper aims to study fabrication and characterization of silver/titanium oxide composite nanoparticle through sonochemical process in the presence of ethylene glycol with alkaline solution. By using ultrasonic irradiation of a mixture of silver nitrate, the dispersed TiO 2 nanoparticle in ethylene glycol associated with aqueous solution of sodium oxide yields Ag/TiO 2 composite nanoparticle with shell/core-type geometry. The powder X-ray diffraction (XRD) of the Ag/TiO 2 composites showed additional diffraction peaks corresponding to the face-centered cubic (fcc) structure of silver crystallization phase, apart from the signals from the cores of TiO 2 . Transmission electron microscopy (TEM) images of Ag/TiO 2 composites, which average particle size is roughly 80nm, reveal that the titanium oxide coated by Ag nanoparticle with a grain size of about 2-5nm. Additionally, the formation of silver nanoparticles on TiO 2 was monitored by ultraviolet visible light spectrophotometer (UV-Vis). As measured the optical absorption spectra of as-synthesized Ag nanoparticle varying with time, the mechanism of surface formatting silver shell on the cores of TiO 2 could be explored by autocatalytic reaction; the conversion of Ag particle from silver ion is 98% for the reaction time of 1000s; and the activity energy of synthesizing Ag nanoparticles on TiO 2 is 40kJ/mol at temperature ranging from 5 to 25 o C. Hopefully, this preliminary investigation could be used for mass production of composite nanoparticles assisted by ultrasonic chemistry in the future. |
