银铜纳米枝晶的生长及光学吸收性质  

Growth of Silver-Copper Nanodendrites and Their Optical Absorption

作　　者：张金生[1] 陈福义[1] 闫晓红[1] 刘婧[1] 樊莉红[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《贵金属》2011年第4期29-35,共7页Precious Metals

基　　金：国家自然科学基金(50971100;50671082);西北工业大学基础研究基金(NPU-FFR-ZC200931);西北工业大学研究生创业种子基金(Z2011002)资助项目;凝固技术国家重点实验室自主研究课题(Grant No.30-TP-2009)

摘　　要：通过电沉积法制备出了Ag-Cu纳米枝晶,并表征了样品的晶体结构、微观形貌以及光学吸收特性。结果表明:当Ag+∶Cu2+>1时,制备出银铜纳米单相合金,Ag+:Cu2+<1/4时,制备出银铜纳米双相合金。当E=-0.2 V时,形成单个银铜纳米粒子和粒子团簇,吸收峰位于402 nm处;随着沉积电位的增加,形成纳米枝晶,且光学吸收峰发生蓝移。在不同成分的银铜合金中,当Ag+∶Cu2+=4∶1时,形成银铜纳米枝晶,吸收峰在358 nm处,随着铜元素的增加,枝晶尺寸减小,光学吸收峰红移。结合电结晶理论和经典枝晶生长理论解释了Ag-Cu纳米枝晶的形成机制。Ag - Cu nanodendrites have been synthesized by the electrodeposition method and their crystal structure, morphology and optical properties of samples were characterized. The results demonstrated that when the molar ratio of the Ag ^＋ to Cu^2＋ is 〉 1, the sample is present as silver - copper single phase nanoalloy, the molar ratio of the Ag^＋to Cu^2＋ 〈 1/4, the sample is silver- copper double phase nanoalloy. When the deposition potential is - 0.2 V, the Ag - Cu material is present as the isolated nanoparticles and particle clusters, the absorption peak is located at about 402 nm. With increasing of the deposition potential, Ag - Cu sample changes into nanodendrites and absorption peak is blue - shifted. For the effects of different ratios of Ag ^＋ to Cu^2 ＋ , the sample is present as the silver - copper nanodendrites and the absorption peak is around 358 nm for Ag ^＋： Cu^2＋ = 4： 1. With increasing of the molar ratio of copper, the size of the nanodendrites decreases and the absorption peak has a red shift. The formation mechanism of Ag - Cu nanodendrites was revealed using the electrocrystallization theory and classical dendritic growth theory.

关 键 词：金属材料 电沉积 银铜纳米枝晶 光学吸收 过电势 过饱和度 枝晶形成机制 

分 类 号：O646[理学—物理化学] O781[理学—化学]