Zhao Jing, Sun Mengtao, Liu Zhe, Quan Baogang, Gu Changzhi, Li Junjie
Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190, China.
Sci Rep. 2015 Nov 2;5:16019. doi: 10.1038/srep16019.
Three dimensional (3D) plasmonic nanostructure is perfect for the surface-enhanced Raman scattering (SERS) and also very suitable for surface catalytic reaction, but how to design and fabricate is still a robust task. Here, we show a 3D plasmonic nanohybrid of vertical graphene-nanosheet sandwiched by Ag-nanoparticles on the silicon nanocone array substrate for enhanced surface catalytic reaction. By SERS detection, we find that this hierarchical nanohybrid structure is highly efficient in the enhancement of catalytic reaction, even at a very low concentration of 10(-11) M, which is far better than previous reports by four orders of magnitude. A strong electric field enhancement produced in the 3D framework nanohybrids of graphene nanosheet/Ag-nanoparticles is responsible for this great enhancement of catalytic reaction, due to larger electron collective oscillation in the composite system. Especially the oxygen adsorbed on the graphene and Ag nanoparticles can be excited to triplet excited states, and the electrons on the graphene and the nanoparticles can be effectively transferred to the oxygen, which plays very important role in molecular catalytic reactions. Our results demonstrate the contribution of graphene in plasmon-driven catalytic reactions, revealing a co-driven reaction process.This excellent SERS substrate can be used for future plasmon and graphene co-catalytic surface catalytic reactions, graphene-based surface plasmon sensors and so on.
三维（3D）等离子体纳米结构非常适合表面增强拉曼散射（SERS），也非常适用于表面催化反应，但如何设计和制造仍然是一项艰巨的任务。在这里，我们展示了一种在硅纳米锥阵列基板上由银纳米颗粒夹着垂直石墨烯纳米片的3D等离子体纳米杂化物，用于增强表面催化反应。通过SERS检测，我们发现这种分级纳米杂化结构在催化反应增强方面非常高效，即使在极低浓度10（-11）M下也是如此，这比以前的报道要好四个数量级。在石墨烯纳米片/银纳米颗粒的3D框架纳米杂化物中产生的强电场增强是催化反应大幅增强的原因，这是由于复合系统中更大的电子集体振荡。特别是吸附在石墨烯和银纳米颗粒上的氧可以被激发到三重激发态，并且石墨烯和纳米颗粒上的电子可以有效地转移到氧上，这在分子催化反应中起着非常重要的作用。我们的结果证明了石墨烯在等离子体驱动催化反应中的贡献，揭示了一种共同驱动的反应过程。这种优异的SERS基板可用于未来的等离子体和石墨烯共催化表面催化反应、基于石墨烯的表面等离子体传感器等。
