Complex bifunctional metal nanostructures for in situ monitoring of nanoparticle-catalyzed reactions by surface-enhanced Raman spectroscopy
Final Report Abstract
In this project we successfully synthesized complex bifunctional metal nanostructures for in situ monitoring of Au-, Pt- and Ag-catalyzed reactions by using surface-enhanced Raman spectroscopy. To realize quantitative kinetic monitoring of fast catalysis, we designed temperature-controlled microfluidic reactors for in situ SERS detection. This device allowed us to investigate reaction mechanisms directly at the Pt-solution interface and distinguish the competing reductions via hydride and molecular hydrogen. In our SERS experiments we found by accident that chemical species on metal surface can be reduced by hot electrons generated under light illumination. According to the results a novel mechanism of counter-half-reaction-promoted hot electron photoreaction is proposed, in which clean light energy is used instead of the conventional chemical reducer to drive the same chemical reduction. In this project we conducted most of the planned experiments and also performed new experiments that came to us during the project period. The results obtained in this project have been summarized and published in several peer-reviewed journal papers. And most of them have already been cited many times by other researchers from different countries. In addition to the potential applications of the scientific findings, we believe that this project has also established a promising method to study chemical processes at the catalytic interfaces. From my personal perspective, the most important future direction of this field (SERS monitoring of catalysis) is the individuation of SERS for different reactions. Since the conditions of catalytic reactions are very different, when the detecting method is optimized for one specific reaction, SERS will become a powerful tool in the mechanistic study of this reaction.
Publications
- Medical Applications of Surface-Enhanced Raman Scattering, Physical Chemistry Chemical Physics 2013, 15, 5329- 5344
Wei Xie, Sebastian Schlücker
- Rationally Designed Multifunctional Plasmonic Nanostructrues for Surface-Enhanced Raman Spectroscopy: a Review, Reports on Progress in Physics 2014, 77, 116502
Wei Xie, Sebastian Schlücker
(See online at https://doi.org/10.1088/0034-4885/77/11/116502) - Gold and Silver Nanoparticle Monomers Are Non-SERS-Active: a Negative Experimental Study with Silica-Encapsulated Raman-Reporter-Coated Metal Colloids, Physical Chemistry Chemical Physics 2015, 17, 21120-21126
Yuying Zhang, Bernd Walkenfort, Jun Hee Yoon, Sebastian Schlücker, Wei Xie
(See online at https://doi.org/10.1039/c4cp05073h) - Hot Electron-Induced Reduction of Small Molecules on Photorecycling Metal Surfaces, Nature Communications 2015, 6, 7570
Wei Xie, Sebastian Schlücker
(See online at https://doi.org/10.1038/ncomms8570) - Metal Nanoparticle-Catalyzed Reduction Using Borohydride in Aqueous Media: a Kinetic Analysis of the Surface Reaction by Microfluidic SERS, Angewandte Chemie-International Edition 2016, 55, 13729-13733
Wei Xie, Roland Grzeschik, Sebastian Schlücker
(See online at https://doi.org/10.1002/anie.201605776)
