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以双还原剂法制备的单晶三角形银纳米盘为模板,在室温HAuCl4溶液中发生多轮置换反应,制备Au-Ag三角纳米环材料。采用TEM、EDX和XRD等检测手段表征反应阶段产物的形貌、组成以及晶体结构。TEM、EDX和电子衍射谱证实Au置换了Ag。反应7轮后纳米盘的面内偶极表面等离子体共振峰从初始的700nm逐步红移到1100nm,形貌从实心盘状逐渐变为空心纳米环。改变每轮加入的HAuCl4量即可精细调节面内偶极峰的红移步进量。通过采用SERS光谱检测方法,随着多步置换反应的进行,提出了一个可行的形成机理机制。
Single-crystal triangular silver nanodisk prepared by double reductant method was used as a template, and Au-Ag triangular nanorings were prepared by multiple rounds of displacement reaction in HAuCl4 solution at room temperature. The morphology, composition and crystal structure of the reaction products were characterized by TEM, EDX and XRD. TEM, EDX and electron diffraction confirmed that Au replaced Ag. After 7 rounds of reaction, the in-plane dipole surface plasmon resonance of the nanodisk gradually red-shifted to 1100 nm from the initial 700 nm, and the morphology gradually changed from a solid disc to a hollow nanorings. Changing the amount of HAuCl4 added in each round finely adjusts the amount of redshift of the in-plane dipole peak. By using the SERS spectral detection method, a feasible mechanism of formation mechanism is proposed with the progress of the multi-step displacement reaction.