Neyshtadt Shany, Kriegel Ilka, Rodríguez-Fernández Jessica, Hug Stephan, Lotsch Bettina, Da Como Enrico
Photonics and Optoelectronics Group, Department of Physics and CeNS, Ludwig-Maximilians-Universität München, Munich, Germany.
Nanoscale. 2015 Apr 21;7(15):6675-82. doi: 10.1039/c5nr00656b.
Here, we describe an electronically coupled hybrid material consisting of graphene oxide (GO) flakes and inorganic Cu(2-x)S nanocrystals (NCs) formed via a self-assembly route. As a result of the amphiphilic nature of the water-dispersible GO flakes, the hydrophobic Cu(2-x)S NCs self-assemble in between the GO flakes, resulting in a large-interface hybrid structure with ordered close-packed NCs. We demonstrate that the optical properties of the hybrid GO/Cu(2-x)S structures are governed by the injection of electrons from the GO flakes to the valence band of the vacancy-doped plasmonic Cu(2-x)S NCs. This leads to a suppression of the plasmon band of the Cu(2-x)S NCs and to a softening of the Raman G-band of the GO flakes. Our results indicate that graphene derivatives can act not only as a self-assembly directing template, but also as a tool to affect the optical properties of self-assembled NCs in a chemical process, enhanced by the high interface area of the composite.
在此，我们描述了一种通过自组装途径形成的由氧化石墨烯（GO）薄片和无机Cu(2-x)S纳米晶体（NCs）组成的电子耦合混合材料。由于水分散性GO薄片的两亲性质，疏水性Cu(2-x)S NCs在GO薄片之间自组装，形成具有有序紧密堆积NCs的大界面混合结构。我们证明，混合GO/Cu(2-x)S结构的光学性质受电子从GO薄片注入到空位掺杂等离子体Cu(2-x)S NCs的价带的控制。这导致Cu(2-x)S NCs的等离子体带受到抑制，以及GO薄片的拉曼G带变软。我们的结果表明，石墨烯衍生物不仅可以作为自组装导向模板，还可以作为在化学过程中影响自组装NCs光学性质的工具，复合材料的高界面面积增强了这种作用。
