title: Fabrication and characterization of silver/titanium dioxide composite nanoparticles in ethylene glycol with alkaline solution through sonochemical process.
abstract: 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 TiO2 nanoparticle in ethylene glycol associated with aqueous solution of sodium oxide yields Ag/TiO2 composite nanoparticle with shell/core-type geometry. The powder X-ray diffraction (XRD) of the Ag/TiO2 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 TiO2. Transmission electron microscopy (TEM) images of Ag/TiO2 composites, which average particle size is roughly 80 nm, reveal that the titanium oxide coated by Ag nanoparticle with a grain size of about 2-5 nm. Additionally, the formation of silver nanoparticles on TiO2 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 TiO2 could be explored by autocatalytic reaction; the conversion of Ag particle from silver ion is 98% for the reaction time of 1000 s; and the activity energy of synthesizing Ag nanoparticles on TiO2 is 40 kJ/mol at temperature ranging from 5 to 25°C. Hopefully, this preliminary investigation could be used for mass production of composite nanoparticles assisted by ultrasonic chemistry in the future.
authors.affiliation: Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan.
authors.forename: Ya-Yi
authors.initials: YY
authors.lastname: Jhuang
authors.affiliation: Department of Chemical Engineering, National Chung Hsing University, Taichung 40227, Taiwan. Electronic address: wtcheng@dragon.nchu.edu.tw.
authors.forename: Wen-Tung
authors.initials: WT
authors.lastname: Cheng
keywords: Composite nanoparticle; Silver; Sonochemical process; Surface synthesis; Titanium dioxide