Swearer Dayne F, Zhao Hangqi, Zhou Linan, Zhang Chao, Robatjazi Hossein, Martirez John Mark P, Krauter Caroline M, Yazdi Sadegh, McClain Michael J, Ringe Emilie, Carter Emily A, Nordlander Peter, Halas Naomi J
Department of Chemistry, Rice University, Houston, TX 77005;
Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005;
Proc Natl Acad Sci U S A. 2016 Aug 9;113(32):8916-20. doi: 10.1073/pnas.1609769113. Epub 2016 Jul 21.
Metallic nanoparticles with strong optically resonant properties behave as nanoscale optical antennas, and have recently shown extraordinary promise as light-driven catalysts. Traditionally, however, heterogeneous catalysis has relied upon weakly light-absorbing metals such as Pd, Pt, Ru, or Rh to lower the activation energy for chemical reactions. Here we show that coupling a plasmonic nanoantenna directly to catalytic nanoparticles enables the light-induced generation of hot carriers within the catalyst nanoparticles, transforming the entire complex into an efficient light-controlled reactive catalyst. In Pd-decorated Al nanocrystals, photocatalytic hydrogen desorption closely follows the antenna-induced local absorption cross-section of the Pd islands, and a supralinear power dependence strongly suggests that hot-carrier-induced desorption occurs at the Pd island surface. When acetylene is present along with hydrogen, the selectivity for photocatalytic ethylene production relative to ethane is strongly enhanced, approaching 40:1. These observations indicate that antenna-reactor complexes may greatly expand possibilities for developing designer photocatalytic substrates.
具有强光学共振特性的金属纳米粒子表现为纳米级光学天线，并且最近作为光驱动催化剂展现出非凡的前景。然而，传统上，多相催化依赖于诸如钯（Pd）、铂（Pt）、钌（Ru）或铑（Rh）等弱光吸收金属来降低化学反应的活化能。在此，我们表明将等离子体纳米天线直接耦合到催化纳米粒子上能够在催化剂纳米粒子内光诱导产生热载流子，从而将整个复合物转变为一种高效的光控反应催化剂。在钯修饰的铝纳米晶体中，光催化氢解吸紧密跟随天线诱导的钯岛局部吸收截面，并且超线性功率依赖性强烈表明热载流子诱导的解吸发生在钯岛表面。当乙炔与氢气同时存在时，相对于乙烷的光催化乙烯生产选择性显著增强，接近40:1。这些观察结果表明天线 - 反应器复合物可能极大地扩展开发定制光催化底物的可能性。
