Schlather Andrea E, Manjavacas Alejandro, Lauchner Adam, Marangoni Valeria S, DeSantis Christopher J, Nordlander Peter, Halas Naomi J
Department of Chemistry, Rice University , Houston, Texas 77005, United States.
Laboratory for Nanophotonics, Rice University , Houston, Texas 77005, United States.
J Phys Chem Lett. 2017 May 4;8(9):2060-2067. doi: 10.1021/acs.jpclett.7b00563. Epub 2017 Apr 25.
There is currently a worldwide need to develop efficient photocatalytic materials that can reduce the high-energy cost of common industrial chemical processes. One possible solution focuses on metallic nanoparticles (NPs) that can act as efficient absorbers of light due to their surface plasmon resonance. Recent work indicates that small NPs, when photoexcited, may allow for efficient electron or hole transfer necessary for photocatalysis. Here we investigate the mechanisms behind hot hole carrier dynamics by studying the photodriven oxidation of citrate ions on Au@SiO@Au core-shell NPs. We find that charge transfer to adsorbed molecules is most efficient at higher photon energies but still present with lower plasmon energy. On the basis of these experimental results, we develop a simple theoretical model for the probability of hot carrier-adsorbate interactions across the NP surface. These results provide a foundation for understanding charge transfer in plasmonic photocatalytic materials, which could allow for further design and optimization of photocatalytic processes.
目前，全球都需要开发高效的光催化材料，以降低常见工业化学过程中高昂的能源成本。一种可能的解决方案聚焦于金属纳米颗粒（NPs），由于其表面等离子体共振，这些纳米颗粒可以作为光的高效吸收体。最近的研究表明，小的纳米颗粒在光激发时，可能会实现光催化所需的高效电子或空穴转移。在这里，我们通过研究柠檬酸根离子在Au@SiO@Au核壳纳米颗粒上的光驱动氧化，来探究热空穴载流子动力学背后的机制。我们发现，在较高光子能量下，电荷转移到吸附分子的效率最高，但在较低等离子体能量下也会发生。基于这些实验结果，我们建立了一个简单的理论模型，用于描述热载流子与吸附物在纳米颗粒表面相互作用的概率。这些结果为理解等离子体光催化材料中的电荷转移提供了基础，这可能有助于进一步设计和优化光催化过程。
