Surface-enhanced Raman spectroscopy (SERS) can attain the “fingerprint” information of molecules from their vibrational transitions for detecting chemical species and thus displays extraordinary application value in studying chemical reaction mechanism catalyzed by noble metal nanoparticles in recent years. Herein, we successfully fabricated bifunctional Ag-Pd triangular nanoplates with integration of catalytic and SERS activities, using Ag triangular nanoplates as templates and Na₂PdCl₄ as Pd precursor in the presence of ascorbic acid acting as reducing agent and polyvinylpyrrolidone serving as stabilizing agent. We found slowly titrating Na₂PdCl₄ solution, compared with the one-shot injection during reaction, can strongly restrain the galvanic replacement reaction and maintain the Ag content, therefore retaining the plasmonic and SERS properties of Ag-Pd triangular nanoplates. By easily adjusting the amount of Na₂PdCl₄, we can optimize the SERS and catalytic activities of Ag-Pd triangular nanoplates. The optimal Ag-Pd triangular nanoplates with dual functionalities are used to follow the catalytic reduction process of 4-nitrothiophenol in the presence of NaBH₄ by SERS. The results reveal 4-nitrothiophenol is directly transformed to 4-aminothiophenol through a one-step route. Thereby, the prepared Ag-Pd triangular nanoplates are effective and suitable for sensitively investigating the catalytic reaction process by in situ SERS.

表面增强拉曼光谱（SERS）可以从分子的振动跃迁中获得分子的“指纹”信息，以检测化学物质，因此在研究近年来由贵金属纳米粒子催化的化学反应机理方面具有非凡的应用价值。在这里，我们成功地合成了具有催化和SERS活性的双功能Ag-Pd三角纳米板，在抗坏血酸作为还原剂和聚乙烯吡咯烷酮作为稳定剂的情况下，以Ag三角纳米板为模板，以Na ₂ PdCl ₄为Pd前体。我们发现缓慢滴定Na ₂ PdCl ₄与反应过程中的单次进样相比，该溶液可以强烈地抑制电流置换反应并保持Ag含量，因此保留了Ag-Pd三角形纳米板的等离激元和SERS特性。通过轻松调节Na ₂ PdCl ₄的含量，我们可以优化Ag-Pd三角形纳米板的SERS和催化活性。在NaBH ₄存在下，使用具有双重功能的最佳Ag-Pd三角纳米板跟踪4-硝基硫酚的催化还原过程由SERS。结果表明4-硝基硫代苯酚通过一步法直接转化为4-氨基硫代苯酚。因此，所制备的Ag-Pd三角形纳米板是有效的并且适合于通过原位SERS敏感地研究催化反应过程。