Nano Lett. 2019 Feb 13;19(2):1301-1306. doi: 10.1021/acs.nanolett.8b04894. Epub 2019 Jan 15.
Strong light-absorbing properties allow plasmonic metal nanoparticles to serve as antennas for other catalysts to function as photocatalysts. To achieve plasmonic photocatalysis, the hot charge carriers created when light is absorbed must be harnessed before they decay through internal relaxation pathways. We demonstrate the role of photogenerated hot holes in the oxidative dissolution of individual gold nanorods with millisecond time resolution while tuning charge-carrier density and photon energy using snapshot hyperspectral imaging. We show that light-induced hot charge carriers enhance the rate of gold oxidation and subsequent electrodissolution. Importantly, we distinguish how hot holes generated from interband transitions versus hot holes around the Fermi level contribute to photooxidative dissolution. The results provide new insights into hot-hole-driven processes with relevance to photocatalysis while emphasizing the need for statistical descriptions of nonequilibrium processes on innately heterogeneous nanoparticle supports.
强吸光特性使等离子体金属纳米粒子能够充当天线，使其他催化剂充当光催化剂。为了实现等离子体光催化，当光被吸收时产生的热电荷载流子必须在通过内部弛豫途径衰减之前加以利用。我们使用快照高光谱成像，在毫秒时间分辨率下演示了在调整载流子密度和光子能量时，光生热空穴在单个金纳米棒的氧化溶解中的作用。我们表明，光诱导的热电荷载流子增强了金的氧化和随后的电溶解速率。重要的是，我们区分了来自带间跃迁的热空穴与费米能级周围的热空穴对光氧化溶解的贡献。研究结果为光催化中的热空穴驱动过程提供了新的见解，同时强调了对固有非均相纳米粒子载体上非平衡过程进行统计描述的必要性。
