Liu Bing, Ma Zhanfang, Li Kai
Department of Chemistry, Capital Normal University, Beijing 100048, China.
J Nanosci Nanotechnol. 2011 Jun;11(6):5001-6. doi: 10.1166/jnn.2011.4115.
Sodium thiosulphate (Na2S2O3) solution was used to etch silver nanoparticles (NPs) and transform them from triangular nanoprisms to hexagonal nanoplates. UV-Vis spectroscopy and transmission electron microscopy were used to monitor the evolution of the hexagonal Ag nanoplates. S2O3(2-) etched the corners of the triangular Ag nanoprisms, and the Ag atoms that were removed aggregated into small clusters. The facet-selective etching effect of S2O3(2-) can be mainly attributed to the surface energy difference of each face of the nanoplate. The mechanism of S2O3(2-) etching also involves formation of Ag2S2O3 on the nanoprisms vertices, which is followed by its hydrolysis and subsequent dissociation of Ag atoms to form stable Ag2S. The hexagonal Ag nanoplates showed higher surface-enhanced Raman scattering activity than the original nanoprisms.
硫代硫酸钠（Na2S2O3）溶液用于蚀刻银纳米颗粒（NPs），并将它们从三角形纳米棱柱转变为六边形纳米片。利用紫外可见光谱和透射电子显微镜监测六边形银纳米片的演变过程。S2O3(2-)蚀刻三角形银纳米棱柱的角，被去除的银原子聚集形成小簇。S2O3(2-)的刻面选择性蚀刻效应主要可归因于纳米片各面的表面能差异。S2O3(2-)蚀刻的机制还涉及在纳米棱柱顶点形成Ag2S2O3，随后其水解以及Ag原子随后解离形成稳定的Ag2S。六边形银纳米片表现出比原始纳米棱柱更高的表面增强拉曼散射活性。
