硅酸盐玻璃中银铜双金属纳米颗粒的精细结构

Fine Structure of Ag-Cu Bimetallic Nanoparticles in Silicate Glass

采用离子交换结合热处理方法制备了银铜纳米颗粒/硅酸盐玻璃复合材料。利用扩展X射线吸收精细结构谱和紫外-可见吸收光谱对复合材料中银铜纳米晶的精细结构进行了表征和分析。结果表明:玻璃中银铜纳米颗粒各自分散在玻璃基质中;银纳米颗粒的Ag—Ag键长由于制备过程中产生的张应力使标准银箔发生了膨胀;铜纳米颗粒表面的Cu—O配位数由于Cu—Cu配位的出现而降低,且Cu—Cu配位数远小于标准铜箔中Cu—Cu的配位数,其键长也发生了收缩。

Bimetallic Ag-Cu nano-particles were prepared via ion-exchange and subsequently thermal treatment. The formation process and local structure of Ag-Cu nano-particles in composite materials were characterized by extended X-ray absorption fine structure technique and ultraviolet-visible absorption spectroscopy, respectively. The results indicate that Ag and Cu nano-particles exist in the silicate glass. Compared to the corresponding value of Ag foil, the nearest-neighboring Ag-Ag distance expanded due to the tensile stress in the synthesis process. The Cu-Cu coordination appeared, inducing a decrease of the Cu-O coordination number. The Cu-Cu coordination number was smaller than the corresponding value of Cu foil, and the Cu-Cu distance contracted compared to the corresponding value of Cu foil.