摘要
Silver dendritic nanonstructures obtained by the potentiostatic electrolysis from different electrolytes at different overpotentials were characterized by the scanning electron microscopy(SEM)technique and X-ray diffraction analysis of the produced particles.The needle-like and fern-like dendrites were formed from the nitrate electrolyte at overpotentials inside and outside plateaus of the limiting diffusion current density,respectively.The three-dimensional pine-like dendrites constructed from approximately spherical grains were formed from the ammonium electrolyte at overpotentials both inside and outside plateaus of the limiting diffusion current density.The morphology of silver dendrites was correlated with their crystal structure at the semi quantiative level.The change of crystal orientation from the strong(111)preferred orientation for the needle-like dendrites to almost randomly orientied spherical grains in the pine-like dendrites obtained at the overpotential outside the plateau of the limiting diffusion current density was observed.This trend in change of crystal orientation and morphology of Ag nanostructures was accompanied by considerable increase of the specific surface area(SSA)of the produced powders.The average crystallite sizes were in the range of 38-50 nm,proving nanostructural character of the formed Ag particles.
采用恒电位电解法用不同电解质、在不同过电位下获得银枝晶纳米结构,并用扫描电镜(SEM)技术和X射线衍射分析对所得粉末进行表征。采用硝酸盐电解质在极限扩散电流密度的平台范围内外,分别形成了银针状和蕨状枝晶。采用氨盐电解质时,在极限扩散电流密度的平台范围内外均形成了由近球形晶粒构成的银三维松树状枝晶。在半量子化水平上,银枝晶的形貌与其晶体结构相关。在极限扩散电流密度平台范围外的过电位条件下形成的松树状枝晶,其晶体取向从针状枝晶的强(111)面择优取向转变为球形晶粒的几乎随机取向,同时,所得粉末的比表面积显著增加。形成的银颗粒的平均晶粒尺寸在38~50 nm之间,证明了其纳米结构特征。
作者
Ljiljana AVRAMOVIC
Evica R.IVANOVIC
Vesna M.MAKSIMOVIC
Miroslav M.PAVLOVIC
Marina VUKOVIC
Jasmina S.STEVANOVIC
Nebojsa D.NIKOLIC
Ljiljana AVRAMOVIC;Evica R.IVANOVIC;Vesna M.MAKSIMOVIC;Miroslav M.PAVLOVIC;Marina VUKOVIC;Jasmina S.STEVANOVIC;Nebojsa D.NIKOLIC(Mining and Metallurgy Institute,Zeleni bulevar 35,Bor,Serbia;Faculty of Agriculture,University of Belgrade,Nemanjina 6,Belgrade-Zemun,Serbia;Vinca Institute of Nuclear Sciences,University of Belgrade,Belgrade,Serbia;Institute of Chemistry,Technology and Metallurgy,Department of Electrochemistry,University of Belgrade,Njegoseva 12,Belgrade,Serbia;Institute for Multidisciplinary Research,University of Belgrade,Kneza Viseslava 1a,Belgrade,Serbia)
基金
supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia under the research project: “Electrochemical synthesis and characterization of nanostructured functional materials for application in new technologies” (Project No. 172046)
