Plasmonic metal nanostructures with the intrinsic property of localized surface plasmon resonance can effectively promote energy conversion in many applications such as photocatalysis, photothermal therapy, seawater desalinization, etc. It is known that not only are plasmonically excited hot electrons generated from metal nanostructures under light irradiation, which can effectively trigger chemical reactions, but also plasmonically induced heating simultaneously occurs. Although plasmonic catalysis has been widely explored in recent years, the underlying mechanisms for distinguishing the contribution of hot electrons from thermal effects are not fully understood. Here, a simple and efficient self-assembly system using silver nanoislands as plasmonic substrates is designed to investigate the photo-induced azo coupling reaction of nitro- and amino-groups at various temperatures. In the experiments, surface-enhanced Raman spectroscopy is employed to monitor the time and temperature dependence of plasmon-induced catalytic reactions. It was found that a combination of hot electrons and thermal effects contribute to the reactivity. The thermal effects play the dominant role in the plasmon-induced azo coupling reaction of nitro-groups, which suggests that the localized temperature must be considered in the development of photonic applications based on plasmonic nanomaterials.

中文翻译：

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银纳米岛的热效应主导等离子体催化

具有局域表面等离子体共振固有特性的等离子体金属纳米结构可以在光催化、光热治疗、海水淡化等许多应用中有效促进能量转换。众所周知，金属纳米结构在光照射下不仅会产生等离激元激发的热电子，有效引发化学反应，而且还会同时发生等离激元诱导加热。尽管近年来等离激元催化得到了广泛的探索，但区分热电子和热效应的潜在机制尚不完全清楚。在这里，设计了一种使用银纳米岛作为等离子体基底的简单高效的自组装系统，用于研究硝基和氨基在不同温度下的光诱导偶氮偶联反应。在实验中，采用表面增强拉曼光谱来监测等离激元诱导的催化反应的时间和温度依赖性。研究发现，热电子和热效应的结合有助于反应活性。热效应在等离激元诱导的硝基偶氮耦合反应中起主导作用，这表明在基于等离激元纳米材料的光子应用的开发中必须考虑局部温度。