金纳米片的低温水相还原法制备及表征

Structural and Spectroscopic Studies of Single-crystal Au Nanoplates Synthesized by Low-temperature Chemical Reduction

采用PVP作表面活性剂,抗坏血酸还原氯金酸的方法制备了单晶金纳米片,利用透射电镜、高分辨透射电镜和紫外可见光谱对产物进行了形貌分析和结构表征,结果显示纳米片为面心立方结构的单晶金,具有良好的晶体结构.紫外可见光谱中除出现位于580 nm的弱表面等离子体共振吸收峰(SPR)和位于975 nm处的强SPR吸收峰外,首次发现在740 nm和835 nm处同时出现了较难观察到的2个四极巨共振峰.并对金纳米片的生长机理进行了初步的分析和探讨,认为表面活性剂PVP诱导了纳米片不同晶面的生长速度.

Au nanoplates were successfully synthesized from the reduction of HAuC14 by ascorbic acid, in the presence of poly（vinyl pyrrolidone） （PVP）. The morphologies and structure of the products were characterized by TEM, HRTEM and UV-vis spectrum. TEM images indicate nanoplates were fcc single crystals with average edge length of 600 nm. For the first time,their UV-vis spectra not only shows a strong absorption peak and a weak absorption peak centered at -975 nm and -580 nm, which originated from in-plane dipole resonance and out-ofplane dipole resonance respectively, but also shows two quadrupole resonances which appeared at 740 nm and 835 nm. A preliminary growth mechanism is also proposed to explain the formation of nanoplates. It is believed that PVP induced different growth rates of various facets of nuclei.