Highly sensitive SERS monitoring of catalytic reaction by bifunctional Ag-Pd triangular nanoplates

الملخص EN

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 tem-plates 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 replace-ment 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 nano-plates with dual functionalities are used to follow the catalytic reduction process of 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 triangu- lar nanoplates are effective and suitable for sensitively investigating the catalytic reaction process by in situ SERS