金属-重掺杂半导体双表面等离子体耦合增强催化反应的单颗粒光谱研究

基于表面等离子体共振效应(SPR)，等离子体光催化材料能有效捕获光能并产生热载流子用于催化反应，是实现高效光化学转换的重要途径之一。然而，热载流子极快的能量弛豫过程以及全光谱太阳光利用率较低，导致基于SPR效应的能量转换效率离实用需求尚有明显差距。针对传统金属和重掺杂半导体SPR材料在光能捕获波段、消光截面和近场增强等方面各自存在的局限性，通过二者结合实现双表面等离子体耦合，有望进一步提升等离子体光催化转换效率。本项目拟结合金属SPR材料和半导体SPR材料来提升耦合体系的光吸收截面，在可见-红外区获得高效光吸收特性，同时利用局域电场强耦合激发产生更多热载流子并促进其分离，并利用近场增强效应和界面“热点”区域促进颗粒表面反应分子的吸附和活化，进而改善其光催化性能；结合单颗粒光谱技术，研究复合体系热载流子传输机制以及双表面等离子体耦合机制，并揭示其催化增强机制，最终实现光能-化学能的高效转换。

Based on the surface plasmon resonance effect (SPR) of metal particles, plasmonic photocatalysts can effectively capture light energy and generate hot carriers for catalytic reactions, which is one of the important ways to achieve efficient photochemical conversion. However, the extremely fast energy relaxation process of hot carriers and the low utilization of full-spectrum sunlight lead to a significant gap between the energy conversion efficiency and practical requirements. Considering the limitations of traditional metal and heavily-doped-semiconductor SPR materials in terms of light energy capture, extinction cross-section, and near-field enhancement, metal-semiconductor coupling is expected to further improve the efficiency of plasmonic photocatalytic conversion. This project intends to combine the metal SPR material and the semiconductor SPR material to improve the light absorption cross section of the coupling system, and thus obtain high-efficiency light absorption in the visible-infrared region. Meanwhile, the strong coupling of local electric field can generate more hot carriers and promote their separation. Furthermore, the near-field enhancement and interface "hot spots" can promote the adsorption and activation of reactive molecules on the particle surface, thereby improving its photocatalytic performance. Single particle spectroscopy was utilized to study the hot carrier transport mechanism and the dual-plasma-coupling mechanism, reveal its catalytic enhancement mechanism, and ultimately achieve efficient conversion of light energy to chemical energy.