Ultrasmall gold nanoparticles anchored to graphene and enhanced photothermal effects by laser irradiation of gold nanostructures in graphene oxide solutions.
Ultrasmall gold nanoparticles anchored to graphene and enhanced photothermal effects by laser irradiation of gold nanostructures in graphene oxide solutions.
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DOI：
10.1021/nn304775h
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发表时间：
2013-01
期刊：
影响因子：
17.1
通讯作者：
A. Zedan;S. Moussa;J. Terner;G. Atkinson;M. S. El-shall
中科院分区：
文献类型：
--
作者：
A. Zedan;S. Moussa;J. Terner;G. Atkinson;M. S. El-shall
在这项工作中，我们展示了尺寸和形状可控的金纳米结构的光热效应与分散在水中的氧化石墨烯纳米片的耦合。这种增强的光热效应可以通过控制金纳米结构的形状和尺寸来调节，从而显著提高了激光诱导金纳米结构尺寸缩小的加热效率。Au-石墨烯纳米片的拉曼光谱直接证明了在含有Au纳米结构的情况下，激光照射氧化石墨烯纳米片后，石墨烯晶格中存在更多的结构缺陷。具有多个缺陷位和空位的激光还原氧化石墨烯纳米片具有较大的比表面积，为直径为2-4 nm的超细金纳米颗粒固定在石墨烯表面提供了有效的成核位置。这种缺陷填充机制降低了超小金纳米颗粒的迁移率，从而稳定了颗粒，防止了Ostwald熟化过程，从而导致了激光尺寸减小的金纳米颗粒的广泛尺寸分布。金纳米结构/氧化石墨烯溶液和超小的金-石墨烯纳米复合材料被认为是光热治疗和将太阳能有效转化为可用热以用于各种热、热化学和热机械应用的有前途的材料。
In this work we demonstrate the coupling of the photothermal effects of gold nanostructures of controlled size and shape with graphene oxide nanosheets dispersed in water. The enhanced photothermal effects can be tuned by controlling the shape and size of the gold nanostructures, which result in a remarkable increase in the heating efficiency of the laser-induced size reduction of gold nanostructures. The Raman spectra of the Au-graphene nanosheets provide direct evidence for the presence of more structural defects in the graphene lattice induced by laser irradiation of graphene oxide nanosheets in the presence of Au nanostructures. The large surface areas of the laser-reduced graphene oxide nanosheets with multiple defect sites and vacancies provide efficient nucleation sites for the ultrasmall gold nanoparticles with diameters of 2-4 nm to be anchored to the graphene surface. This defect filling mechanism decreases the mobility of the ultrasmall gold nanoparticles and, thus, stabilizes the particles against the Ostwald ripening process, which leads to a broad size distribution of the laser-size-reduced gold nanoparticles. The Au nanostructures/graphene oxide solutions and the ultrasmall gold-graphene nanocomposites are proposed as promising materials for photothermal therapy and for the efficient conversion of solar energy into usable heat for a variety of thermal, thermochemical, and thermomechanical applications.