Modulating the plasmon-mediated silver oxidation using thiophenol molecules as monitored by in situ SERS spectroscopy.

Effective charge separation is essential in plasmon-mediated photochemistry and is usually achieved by constructing plasmon-semiconductor interfaces, which is usually challenging. In this work, by monitoring the plasmon-mediated silver oxidation with in situ Raman spectroscopy, we demonstrate that the adsorbed thiophenol molecules could modulate the rate of photochemical reactions by tuning the charge separation at the plasmon-molecule interfaces. It is found that the thiophenol molecules with strong electron-withdrawing or donating functional groups could accelerate or decelerate the rate of plasmon-mediated silver oxidation, respectively. Owing to the easy tuning of the electronic structures of organic molecules via substitution, our method provides a versatile and convenient approach for the fine modulation of plasmon-mediated photochemical reactions.