LAUSR

The excitation of plasmon resonances in nanostructured materials has been shown to drive catalytic processes. The ability to tune plasmon resonances across the solar spectrum has sparked interest in plasmonic catalysis for many applications. Results indicate that nanostructures with tight junctions can generate direct current (DC) electric fields, arising from optical rectification (OR). The impact of OR generated DC electric fields on plasmonic catalysis is not known. In this work, we use a mixed monolayer of p-mercaptobenzonitrile (MBN) and either 4-nitrothiophenol (NTP) or 4-aminothiophenol (ATP) to correlate the DC field with surface catalytic activity. The DC electric field strength is measured using a vibrational Stark reporter (MBN). The catalytic activity is assessed by monitoring the formation of 4,4-dimercaptoazobenzene and loss of NTP/ATP using changes in the observed surface-enhanced Raman spectrum. Our data shows that at relatively low laser powers, optical rectification modulates the plasmon...