title: Facile synthesis of bimetallic Cu-Ag nanoparticles under microwave irradiation and their oxidation resistance.
abstract: Air-stable bimetallic Cu-Ag nanoparticles in the range of 12-30 nm have been synthesized at gram scale by a facile alcohol reduction in the absence of surfactants with the assistance of microwave irradiation. The synthesized nanoparticles were analyzed by x-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning TEM, ultraviolet-visible spectroscopy, x-ray photoelectron spectroscopy and thermogravimetry (TG). The stability of the bimetallic nanoparticles against oxidation was examined by TG and in situ temperature-programmed XRD analyses in the atmosphere. No oxidation of copper was confirmed by XRD after storing for longer than 6 months in the atmosphere at room temperature. No oxidation took place below 118 ° C and the Cu(200) diffraction peak decreased by only 7% after heating at 100 ° C for 30 min. The oxidation resistance has been ascribed to a Cu core-Ag shell structure, probably owing to the suppressive effect of Ag on the surface through the electronic interaction with Cu and a physical barrier of oxygen.
authors.affiliation: College of Materials Science and Engineering, China Jiliang University, No. 258 Xueyuan Street, Xiasha Higher Education District, Hangzhou 310018, People's Republic of China. zchen0@gmail.com
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.forename: Dai
authors.initials: D
authors.lastname: Mochizuki
authors.forename: Masato M
authors.initials: MM
authors.lastname: Maitani
authors.forename: Yuji
authors.initials: Y
authors.lastname: Wada