Au@Ag nanorod horizontal arrays: Self-assembly preparation and in situ monitoring SERS of plasmonic catalytic reaction

Here, we successfully synthesized silver-coated gold nanorods (Au@Ag NRs) via a facile wet chemical method . The catalytic property of Au@Ag NRs in water solution was much better than that of Au NRs in water solution. To obtain high catalytic properties, we self-assembled a single-layer Au@Ag NR array by evaporation on a silicon wafer . The catalytic activity of the Au@Ag NR array was probed using the reduction of 4-nitrothiophenol. The reaction processes were monitored and identified through in situ surface-enhanced Raman spectroscopy based on the confocal Raman microscope system. This study provides a simple and fast method to improve the catalytic property of the noble nanoparticles .