以SDS-PEG团簇为软模板在温和条件下合成金纳米环

介绍一种由十二烷基硫酸钠(SDS)与聚乙二醇(PEG 20000)组成的团簇为软模板, 在室温、常压、无硬模板及无外加还原剂条件下自还原HAuCl₄合成金纳米环的新方法. TEM显示合成的金纳米环的直径为(500±50) nm; UV-vis光谱显示在800 nm以上区域有强吸收带, 证明有大的各向异性的纳米结构生成. 电子衍射(ED)显示合成的金纳米环为金单晶结构; XRD显示金纳米环的(200)与(111)衍射峰的强度比(I₍₂₀₀₎/I₍₁₁₁₎)为0.11, 比反应初始阶段的0.31降低0.2左右, 表明金纳米结构主要为(111)晶面取向. TEM和SEM跟踪显示, 金纳米环的生长经历了从金纳米球到纳米片再到纳米环的变化过程, 控制反应时间可以得到预期的金纳米结构.

Synthesis of Au Nanorings Using SDS-PEG Cluster as the Soft Template under Mild Conditions

A novel method to prepare Au nanorings by self-reduction of HAuCl₄ in the soft template composed of sodium dodecyl sulfate (SDS)-PEG 20000 cluster at ambient temperature and atmosphere is reported, in which no hard template and extra reducer is needed. TEM image displays that the diameter of Au nanorings is (500±50) nm. UV-vis spectrum reveals that there is relatively stronger absorption band beyond 800 nm, which is attributed to big and anisotropic nanostructures. Electron diffraction (ED) pattern shows that the synthesized nanoring is monocrystal Au. XRD pattern of the Au nanorings indicates that the ratio of the intensity between the (200) and (111) diffraction peaks I₍₂₀₀₎/I₍₁₁₁₎] is 0.11. The fact that I₍₂₀₀₎/I₍₁₁₁₎] decreases 0.2 from the original 0.31 suggests that Au nanorings grow preferentially along (111) lattice planes. The process of Au nanoparticles growing from nanospheres through nanoplates and eventually to nanorings is tracked by both TEM and SEM, which indicates that if the reduction period is controlled the preferred Au nanostructures could be obtained.