Interfacial Structure-Modulated Plasmon-Induced Water Oxidation on Strontium Titanate
Interfacial Structure-Modulated Plasmon-Induced Water Oxidation on Strontium Titanate
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DOI：
10.1021/acsaem.0c00648
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发表时间：
2020-06-22
影响因子：
6.4
通讯作者：
Misawa, Hiroaki
中科院分区：
文献类型：
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作者：
Shi, Xu;Li, Xiaowei;Misawa, Hiroaki
金属纳米颗粒/半导体异质结中的等离子体激元诱导载流子转移因其在光电转换、能量转换等方面的巨大应用潜力而受到广泛关注。已知异质结的界面结构在电荷转移以及随后的化学反应中起重要作用。本文以Au纳米粒子（Au-NP）负载的（100）、（110）和（111）取向的单晶钛酸锶（STO）为模型，研究了界面结构对金属纳米粒子与半导体之间等离子体激元诱导的电荷分离的影响。通过光电化学表征，我们发现STO（100）晶面上的等离子体激元诱导水氧化反应的效率是其他两个晶面上的1.4倍以上。这种增强被证明是源于高氧化能力的等离子体诱导的空穴捕获在表面状态。此外，利用原位电化学表面增强拉曼光谱技术监测了Au-NP/STO作为等离子体诱导水氧化中间体的表面氧化状态，研究了水氧化的分子过程.在Au-NP/STO（100）上的Au-O振动的起始电势被确定为比Au-NP/STO（110）的起始电势负0.4V，进一步证实了等离子体激元诱导的空穴的更高的氧化能力。我们的观察提供了一个机会，有效地调制等离子体激元激发的热载流子反应过程中的光化学应用，通过界面工程。
Plasmon-induced carrier transfer at metallic nanoparticle/semiconductor heterojunctions has received great attention because of its tremendous potential in applications, such as photocatalysis and photoelectric and energy conversion. The interfacial structure of the heterojunction is known to play an important role in charge transfer as well as the subsequent chemical reactions. Here, we studied the Au nanoparticle (Au-NP)-loaded (100)-, (110)-, and (111)-oriented single-crystalline strontium titanate (STO) as a model to investigate the effects of interfacial structure on the plasmon-induced charge separation between the metallic nanoparticles and semiconductors. Via photoelectrochemical characterizations, we found that the efficiency of the plasmon-induced water oxidation reaction on STO(100) is more than 1.4 times higher than that on the other two orientation facets. This enhancement was demonstrated to stem from the high oxidation ability of plasmon-induced holes captured in the surface states. Furthermore, the molecular processes of water oxidation were investigated by monitoring the surface oxidation status of Au-NP/STO as intermediates of plasmon-induced water oxidation using in situ electrochemical surface-enhanced Raman spectroscopy. The onset potential of Au-O vibrations on Au-NP/STO(100) was determined to be 0.4 V more negative than that of Au-NP/STO(110), further confirming the higher oxidation ability of the plasmon-induced holes. Our observation provides an opportunity to efficiently modulate plasmon-excited hot-carrier reaction processes for photochemical applications through interfacial engineering.