摘要
采用多波长(1064nm、532nm、248nm)脉冲激光在去离子水中对贵金属Au、Ag片表面进行激光烧蚀(PLA)。利用TEM、AFM、SEM对烧蚀金属片表层及产物(微/纳米尺度的金属颗粒)进行观察分析,认为在液相水环境中,整个烧蚀过程主要可分为激光诱导相沸腾爆炸和等离子体羽辉混合体膨胀2个过程。在这2个过程中分别产生得到具有微米尺度的球状金属颗粒和纳米尺度的金属颗粒。同时,具有纳米尺度金属Au/Ag颗粒经过强激光光子"二次"修饰改性过程,形成具有形状统一、分散性和稳定性较好的金属纳米胶体体系,这些胶体中金属纳米颗粒作为探针,在表面增强拉曼散射(SERS)光谱学方面有很好的应用价值。
Noble metal Au/Ag plates are ablated by pulse laser with 1064nm,532nm and 248nm in de-ionized water. With the observation and measurement of Au/Ag surface and its products（microparticles and nanoparticles） by the AFM, SEM and TEM, it＇s considered that the process of pulse laser ablation（PLA） in water can be divided into laser induced explosive boiling and the explosion of plasma feathers. The first process of PLA generated micro-scaled metal particles, and in the second process, the explosion of plasma feathers brought out nano-scaled metal particles. Syn- chronously, the Au/Ag nanoparticles are modified again by laser-photons into homogeneous sized and table metal nano- particles colloids system. The nano-scaled Au/Ag particles can be well applied in enhanced Raman scattering （SERS） as highly efficient SERS-active probes.
基金
北京市自然科学基金(2982010)
关键词
脉冲激光
液相烧蚀
Au/Ag纳米颗粒
烧蚀机理
相爆炸
等离子体羽辉
pulsed laser ablation, liquid phase ablation, Au/Ag nanoparticles, ablation mechanism, phase explosion, plasma plume
