Liu Yawei, Chen Qiaoli, Cullen David A, Xie Zhaoxiong, Lian Tianquan
Department of Chemistry, Emory University, 1515 Dickey Drive, NE, Atlanta, Georgia 30322, United States.
State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
Nano Lett. 2020 Jun 10;20(6):4322-4329. doi: 10.1021/acs.nanolett.0c01050. Epub 2020 May 14.
Many important chemical transformations enabled by plasmonic hot carrier photocatalysis have been reported, although their efficiencies are often too low for practical applications. We examine how the efficiency of plasmon-induced hot electron transfer depends on the Au particle size in Au-tipped CdS nanorods. We show that with decreasing Au size, the plasmon width increases due to enhanced surface damping contributions. The excitation of Au nanoparticles leads to an instrument response time-limited ultrafast hot electron transfer process to CdS (≪140 fs). The quantum efficiency of this process increases from ∼1% to ∼18% as the particle size decreases from 5.5 ± 1.1 to 1.6 ± 0.5 nm due to both enhanced hot electron generation and transfer efficiencies in small Au particles. Our finding suggests that decreasing plasmonic particle size is an effective approach for improving plasmon-induced hot carrier transfer efficiency and provides important insight for the rational improvement of plasmonic hot carrier-based devices.
尽管等离子体热载流子光催化实现的许多重要化学转化的效率对于实际应用而言往往过低，但相关报道已有不少。我们研究了等离子体诱导的热电子转移效率如何取决于金包覆硫化镉纳米棒中金颗粒的尺寸。我们发现，随着金颗粒尺寸减小，由于表面阻尼贡献增强，等离子体宽度增大。金纳米颗粒的激发导致一个受仪器响应时间限制的超快热电子转移过程至硫化镉（≪140飞秒）。随着颗粒尺寸从5.5±1.1纳米减小至1.6±0.5纳米，这一过程的量子效率从约1%增至约18%，这是由于小金颗粒中热电子产生和转移效率均得到增强。我们的发现表明，减小等离子体颗粒尺寸是提高等离子体诱导热载流子转移效率的有效方法，并为基于等离子体热载流子的器件的合理改进提供了重要见解。
