The crystal phase of noble metals has been identified as one of the key parameters that can greatly affect their properties and functionalities. However, research on the crystal-phase-dependent catalytic activities of noble metals has been rarely reported. Here, we report a systematic study of surface-plasmon-driven hot-electron-induced photocatalytic reduction of para-nitrothiophenol (pNTP) to p,p′-dimercaptoazobenzene under visible light on Au nanostructures with different crystal phases by in-situ surface-enhanced Raman spectroscopy (SERS). Our results indicate that the photocatalytic rate of unconventional 4H Au is nearly 6–8 times that of conventional face-centered cubic (fcc) Au, suggesting the greater activity of hot electrons on 4H Au. Further electrochemical reductions of pNTP on the 4H and fcc Au nanostructures in aqueous solutions also confirm the higher catalytic activity of the 4H Au. Our study demonstrates that the synthesis of Au nanomaterials with controlled crystal phases paves the way for developing highly efficient catalyst.

中文翻译：

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表面增强拉曼光谱原位探测Au纳米结构的晶相依赖性光催化活性

贵金属的晶相已被确定为可以极大地影响其性能和功能的关键参数之一。然而，很少有关于贵金属的晶体相依赖性催化活性的研究的报道。在这里，我们报告了表面等离子体激元驱动的电子催化光催化原位表面不同晶相的金纳米结构上的对硝基硝基苯酚（p NTP）还原为p，p′-二巯基偶氮苯的光催化反应。增强拉曼光谱（SERS）。我们的结果表明，非常规4H Au的光催化速率几乎是常规面心立方（fcc）Au，表明热电子对4H Au具有更大的活性。在水溶液中4H和fcc Au纳米结构上p NTP的进一步电化学还原也证实了4H Au的更高催化活性。我们的研究表明，具有受控晶相的金纳米材料的合成为开发高效催化剂铺平了道路。