激光液相烧蚀法制备SnS纳米材料和均匀分散Cd纳米晶.pdf

摘 要 本文采用激光液相烧蚀法制备新型的 Sn@SnS 核壳纳米颗粒，又结合化学 刻蚀法获得 SnS 空心纳米颗粒等新奇结构；通过使用激光液相破碎法，制备了 尺寸可调、分散性良好的均匀 Cd 纳米晶。 通过毫秒激光烧蚀 TAA 乙醇溶液中 Sn 靶，制备了 Sn@SnS 核壳纳米颗 粒，并且能够通过对硫源浓度的控制来调节硫化壳层的厚度，给出了在此条件下 形成核壳纳米颗粒的机理为“Sn 金属纳米液滴的表面硫化反应”。在核壳结构 的基础上，结合化学刻蚀法得到 SnS 空心纳米颗粒等新奇结构，研究了溶液的 PH 值以及不同种类的酸性刻蚀剂对空壳形貌的影响。利用纳秒激光烧蚀 TAA 乙醇溶液中的 Sn 靶一步合成 SnS 的多孔空壳结构，详细探讨并证明了该结构 的形成机理。 通过纳秒激光多次辐照油酸乙醇溶液中分散性较差、粒径大小不均的初始 Cd 纳米晶，成功制备了尺寸可调、分散性良好的均匀 Cd 纳米晶。研究了激光 能量密度、辐照时间、油酸的浓度等实验参数对 Cd 纳米晶分散性和最终尺寸 的影响。结合理论计算，详细阐述了 Cd 纳米晶在激光液相破碎过程中的“加 热-熔化-气化”机制。 关键词：激光液相烧蚀 Sn@SnS 核壳纳米颗粒 SnS 空心纳米颗粒 化学刻蚀 激光液相破碎 Cd 纳米晶 ABSTRACT In this thesis, Sn@SnS core-shell nanoparticles were first fabricated by laser ablation in liquid, and then SnS hollow nanoparticles were obtained by following chemical etching process. Moreover, uniform Cd nanocrystals with adjustable size and good dispersion were prepared via laser fragmentation in liquid. Sn@SnS core-shell nanoparticles were prepard by millisecond pulsed laser ablation of Sn target in ethanol solution of thioacetamide, and the shell thickness of the core-shell nanoparticles could be facilely modified by adjusting the concentrat ion of thioacetamide. We proposed a formation mechanism of core-shell nanoparticles based on “surface vulcanization of Sn nanodroplets”. Subsequently, acid etching was excuted on core-shell structure to eliminate the Sn cores; finally SnS hollow nanopartic les were obtained. The PH value of the solution and the category of the etching agent were found to have a significant impact on the shell morphology. We also synthesized porous SnS nanoparticles with