A new green, ascorbic acid-assisted method for versatile synthesis of Au-graphene hybrids as efficient surface-enhanced Raman scattering platforms
A new green, ascorbic acid-assisted method for versatile synthesis of Au-graphene hybrids as efficient surface-enhanced Raman scattering platforms
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DOI：
10.1039/c3tc30177j
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发表时间：
2013-01-01
影响因子：
6.4
通讯作者：
Astilean, Simion
中科院分区：
文献类型：
--
作者：
Iliut, Maria;Leordean, Cosmin;Astilean, Simion
报道了一种在水溶液中合成还原氧化石墨烯 - 金纳米粒子（rGO - AuNP）杂化物的新型绿色方法，该方法利用了抗坏血酸（AA）作为氧化石墨烯（GO）和金离子还原的有效双重试剂的能力。通过对用聚乙烯吡咯烷酮（PVP）稳定的rGO - AuNP杂化物制备的仔细研究，设计了几种通用的途径，目的是控制锚定在石墨烯片上的AuNPs的大小、形状和分布以及GO的还原。特别是，当rGO用作金离子成核的平台时，注意到尺寸在20nm到50nm范围内的AuNPs相对稀疏分布。相反，当在任何GO还原之前将金离子添加到溶液中时，相对于均匀堆积的小尺寸AuNPs（3 - 12nm），大AuNPs的密度相当低。除了AA的还原活性外，还通过考虑AuNPs的催化活性的贡献来解释GO还原的过程。最后，假设了一种关于AuNPs在石墨烯表面成核和分布的合理机制，强调了氧官能团的重要性。这里开发的绿色方法对于制备具有可调表面“修饰”的金 - 石墨烯纳米复合材料是有前景的，适用于表面增强拉曼光谱（SERS）。
A new green method for the synthesis of reduced graphene oxide-gold nanoparticle (rGO-AuNP) hybrids in aqueous solution that exploits the ability of ascorbic acid (AA) to operate as an effective dual agent for both graphene oxide (GO) and gold ion reduction is reported. Through careful investigation of the production of rGO-AuNP hybrids stabilized with polyvinylpyrrolidone (PVP), several versatile routes were devised with the aim of controlling the size, shape and distribution of AuNPs anchored onto the graphene sheets as well as the GO reduction. Particularly, when rGO is used as a platform for Au ion nucleation, a relative sparse distribution of AuNPs of size ranging from 20 nm to 50 nm is noticed. In contrast, when gold ions are added to the solution prior to any GO reduction, the density of large AuNPs is rather low relative to the uniformly packed small sized AuNPs (3-12 nm). The progress of GO reduction is explained by considering the contribution of the catalytic activity of AuNPs, besides the reducing activity of AA. Finally, a plausible mechanism for the nucleation and distribution of AuNPs onto the graphenic surface is assumed, highlighting the significance of oxygen moieties. The green method developed here is promising for the fabrication of gold-graphene nanocomposites with tunable surface "decoration", suitable for surface-enhanced Raman spectroscopy (SERS).