Ag/石墨烯复合材料的制备及其对邻氨基苯甲酸甲酯的SERS效应

Preparation of Ag / graphene nanocomposite and its SERS effect on methyl anthranilate

以还原的氧化石墨烯（r-GO）为前驱物，采用紫外光照还原和水合肼还原两个不同的合成过程，简单制得了没有有机分子存在的Ag沉积r-GO纳米复合材料，其中被还原的Ag呈颗粒状沉积在r-GO片层表面。由于紫外光照还原反应速率较慢，制得的Ag颗粒分散性相对较好，尺寸分布较窄，粒径主要处在25～80nm间；而用水合肼还原，因反应速率较快，获得的Ag颗粒团聚较严重，尺寸分布较宽，粒径主要处在20～130nm间。在此基础上，以一种香料邻氨基苯甲酸甲酯为标记分子，在波长为785nm激光激发下，对获得的一系列含Ag复合材料进行了表面增强Ra-man散射光谱（SERS）测试，结果表明，它们具有非常高的SERS效应，增强因子在10^8附近，其中，用水合肼还原制得的复合材料SERS效应更加明显。

Ag-deposited reduced graphene oxide （r-GO） nanocomposites, without any additional organic mole- cules, were obtained simply through two different preparation processes of ultra-violet reduction and hydrazine reduction. It has been demonstrated that particle-shaped Ag was formed on the surface of r-GO. Using ultra-vi- olet reduction route, due to very slow reduction reaction, Ag particles on the r-GO surface exhibit relatively good dispersion and narrow size distribution with a diameter range of 25-80 nm. However, under hydrazine re- duction, Ag particles show severely aggregation and wide size distribution with a diameter range of 20-130 nm due to fast reduction reaction. Based on the preparations, the surface-enhanced Raman scattering （SERS） spec- troscopes of methyl anthranilate molecules on a series of Ag-deposited r-GO samples were measured in detail, and the results show that such composites have high SERS effect on the organic molecules with an enhancement factor of an order of 10^8 , in which the composite prepared from hydrazine reduction shows obviously higher.