Origin of Superlinear Power Dependence of Reaction Rates in Plasmon-Driven Photocatalysis: A Case Study of Reductive Nitrothiophenol Coupling Reactions
Origin of Superlinear Power Dependence of Reaction Rates in Plasmon-Driven Photocatalysis: A Case Study of Reductive Nitrothiophenol Coupling Reactions
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DOI：
10.1021/acs.nanolett.3c00195
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发表时间：
2023-03-15
期刊：
影响因子：
10.8
通讯作者：
Wang, Hui
中科院分区：
文献类型：
--
作者：
Chen, Kexun;Wang, Hui
反应速率对激发光的功率的超线性依赖性，这可能是由热和非热效应引起的，已经成为等离子体激元驱动的纳米结构金属表面的特征。然而，它仍然具有挑战性，以区分和量化的热和非热效应，因为即使是轻微的不确定性，在测量的局部温度在活性表面网站可能会导致显着的错误，在评估热和非热的贡献，以整体反应速率。在这里，我们采用表面增强的拉曼散射作为一个表面敏感的原位光谱工具，相关的等离子体介导的分子trans-formations在光催化剂表面上的活性位点的局部温度的详细动力学特征。我们的光谱结果清楚地表明，在等离子体激元驱动的模型反应中观察到的反应速率的功率依赖性的超线性，特别是对硝基硫酚吸附在银纳米颗粒表面的还原偶联，基本上源于光热加热，而不是非热等离子体效应。
The superlinear dependence of the reaction rate on the power of the excitation light, which may arise from both thermal and nonthermal effects, has been a hallmark of plasmon-driven photocatalysis on nano-structured metal surfaces. However, it remains challenging to distinguish and quantify the thermal and nonthermal effects because even slight uncertainties in measuring the local temperatures at the active surface sites may lead to significant errors in assessing thermal and nonthermal contributions to the overall reaction rates. Here we employ surface-enhanced Raman scattering as a surface-sensitive in situ spectroscopic tool to correlate detailed kinetic features of plasmon-mediated molecular trans-formations to the local temperatures at the active sites on photocatalyst surfaces. Our spectroscopic results clearly reveal that the superlinearity in the power dependence of the reaction rate observed in a plasmon-driven model reaction, specifically the reductive coupling of para-nitrothiophenol adsorbates on Ag nanoparticle surfaces, originates essentially from photothermal heating rather than nonthermal plasmonic effects.