Division of Physical Biology and Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
Nano Lett. 2020 Apr 8;20(4):2507-2513. doi: 10.1021/acs.nanolett.9b05255. Epub 2020 Mar 19.
Plasmon-mediated photocatalysis provides a novel strategy for harvesting solar energy. Identification of the rate-determining step and its activation energy in plasmon-mediated photocatalysis plays critical roles for understanding the contribution of hot carriers, which facilitates rational designation of catalysts with integrated high photochemical conversion efficiency and catalytic performance. However, it remains a challenge due to a lack of research tools with spatiotemporal resolution that are capable of capturing intermediates. In this work, we used a single-molecule fluorescence approach to investigate a localized surface plasmon resonance (LSPR)-enhanced photocatalytic reaction with subturnover resolution. By introducing variable temperature as an independent parameter in plasmonic photocatalysis, the activation energies of tandem reaction steps, including intermediate generation, product generation, and product desorption, were clearly differentiated, and intermediate generation was found to be the rate-limiting step. Remarkably, the cause of the plasmon-enhanced catalysis performance was found to be its ability of lowering the activation energy of intermediate generation. This study gives new insight into the photochemical energy conversion pathways in plasmon-enhanced photocatalysis and sheds light on designing high-performance plasmonic catalysts.
等离子体介导的光催化为太阳能的收集提供了一种新的策略。确定等离子体介导的光催化中的速率决定步骤及其活化能对于理解热载流子的贡献至关重要，这有助于合理设计具有集成高光化学转化效率和催化性能的催化剂。然而，由于缺乏具有时空分辨率的研究工具来捕获中间体，因此这仍然是一个挑战。在这项工作中，我们使用单分子荧光方法在亚转化率分辨率下研究了局部表面等离子体共振（LSPR）增强的光催化反应。通过在等离子体光催化中引入可变温度作为独立参数，可以清楚地区分串联反应步骤（包括中间产物生成、产物生成和产物解吸）的活化能，并且发现中间产物生成是限速步骤。值得注意的是，发现等离子体增强催化性能的原因是其降低中间产物生成的活化能的能力。这项研究为等离子体增强光催化中的光化学能量转化途径提供了新的见解，并为设计高性能等离子体催化剂提供了启示。
