高表面粗糙度银纳米线的分形研究和SERS效应

Fractal Study and SERS Effect of Silver Nanowires with High Surface Roughness

为了获得分布均匀、有序排列、可重复性高的表面增强拉曼散射基底(SERS),选取银离子导体RbAg4I5薄膜,结合真空热蒸镀工艺和固态离子学方法在外加电流作用下制备出高表面粗糙度的银纳米线。同时,选取罗丹明6G(R6G)溶液作为探针分子,研究高表面粗糙度银纳米线作为SERS基底时的表面增强拉曼特性。实验结果表明:制备得到的银纳米线在宏观上呈现为树枝状,在微观上呈现为有序排列,并且其纳米结构的分形维数为1.59;采用银纳米线作为SERS基底时,能够检测到R6G溶液的浓度低至10^-17 mol/L。制备的高表面粗糙度和有序密集排列的银纳米线SERS基底在环境科学等领域具有潜在的应用前景。

Herein, silver nanowires with high surface roughness are prepared via vacuum thermal evaporation and a solid-state ionics method. The nanowires are assembled into silver conductor RbAg4I5 films under the imposed current intensity, obtaining surface-enhanced Raman scattering(SERS) substrates with highly uniform, well ordered, and high-repeatability. The surface enhanced Raman characteristics of the silver-nanowire substrates with high surface roughness are detected using Rhodamine 6 G(R6 G) probe molecules in aqueous solution. The experimental results show that the prepared silver nanowires are branch-shaped and orderly arranged in the macro and micro structures, respectively;the fractal dimension of the silver nanostructure is 1.59. The method detects molar R6 G concentration as low as 10^-17 mol/L when the silver nanowires are used as SERS substrates. The prepared silver nanowires with orderly dense arrangement and high surface roughness confirm its potential applicability in environmental sciences and other fields.