Arnob Md Masud Parvez, Artur Camille, Misbah Ibrahim, Mubeen Syed, Shih Wei-Chuan
Department of Chemical and Biochemical Engineering , University of Iowa , Iowa City , Iowa 52242 , United States.
ACS Appl Mater Interfaces. 2019 Apr 10;11(14):13499-13506. doi: 10.1021/acsami.8b19914. Epub 2019 Mar 26.
Certain noble metal nanostructures as heterogeneous photocatalysts have drawn significant attention in the recent past because of their unique optical properties which lead to the excitation of localized surface plasmon resonance (LSPR). The LSPR concentrates electromagnetic fields to the surfaces and its relaxation processes can convert photon energy to energetic charge carriers or heat, which can be subsequently harvested to enhance surface catalysis. Here, we report the catalytic performance of a novel plasmonic nanostructure, disk-shaped nanoporous gold (NPG) nanoparticles or simply NPG disks, using a well-tested reduction pathway of resazurin to resorufin. We show that the catalytic reaction rate of NPG disks is enhanced by 10-fold upon external light illumination because of the excitation of LSPR. The plasmon-enhanced catalytic reaction follows a linear-to-superlinear transition in the rate dependence on the input light power. In addition, the light input results in a room temperature reaction rate equivalent to that of an ambient temperature of 70 °C. Together, the results support that hot charge carriers play the dominant role in the enhancement.
某些贵金属纳米结构作为多相光催化剂，因其独特的光学性质能够引发局域表面等离子体共振（LSPR），在最近受到了广泛关注。LSPR将电磁场集中到表面，其弛豫过程可将光子能量转化为高能电荷载流子或热量，随后可利用这些能量来增强表面催化作用。在此，我们利用一种经过充分测试的刃天青还原为试卤灵的途径，报告了一种新型等离子体纳米结构——盘状纳米多孔金（NPG）纳米颗粒，即简单的NPG盘的催化性能。我们表明，由于LSPR的激发，外部光照下NPG盘的催化反应速率提高了10倍。等离子体增强催化反应在速率对输入光功率的依赖性上呈现从线性到超线性的转变。此外，光输入导致室温下的反应速率等同于70°C环境温度下的反应速率。这些结果共同支持了热电荷载流子在增强过程中起主导作用。
