Reactive hot spots on plasmonic nanoparticles have attracted attention for photocatalysis as they allow for efficient catalyst design. While sharp tips have been identified as optimal features for field enhancement and hot electron generation, the locations of catalytically promising d-band holes are less clear. Here we exploit d-band hole-enhanced dissolution of gold nanorods as a model reaction to locate reactive hot spots produced from direct interband transitions, while the role of the plasmon is to follow the reaction optically in real time. Using a combination of single-particle electrochemistry and single-particle spectroscopy, we determine that d-band holes increase the rate of gold nanorod electrodissolution at their tips. While nanorods dissolve isotropically in the dark, the same nanoparticles switch to tip-enhanced dissolution upon illimitation with 488 nm light. Electron microscopy confirms that dissolution enhancement is exclusively at the tips of the nanorods, consistent with previous theoretical work that predicts the location of d-band holes. We, therefore, conclude that d-band holes drive reactions selectively at the nanorod tips.

中文翻译：

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d 波段空穴在金纳米棒的尖端发生反应

等离子体纳米粒子上的反应热点引起了人们对光催化的关注，因为它们允许进行有效的催化剂设计。虽然尖锐尖端已被确定为场增强和热电子产生的最佳特征，但催化有希望的 d 带空穴的位置不太清楚。在这里，我们利用金纳米棒的 d 带空穴增强溶解作为模型反应来定位直接带间跃迁产生的反应热点，而等离激元的作用是实时光学跟踪反应。结合使用单粒子电化学和单粒子光谱学，我们确定 d 带孔增加了金纳米棒尖端的电溶解速率。当纳米棒在黑暗中各向同性溶解时，在用 488 nm 光限制时，相同的纳米颗粒会切换到尖端增强溶解。电子显微镜证实溶解增强仅发生在纳米棒的尖端，这与先前预测 d 带孔位置的理论工作一致。因此，我们得出结论，d 带空穴在纳米棒尖端选择性地驱动反应。