Revealing the difference of Stark tuning rate between interface and bulk by surface-enhanced infrared absorption spectroscopy

Revealing the factors that affect the vibrational frequency of Stark probe at interface is a pre-requirement for evaluating the absolute interfacial electric field.Here using surface-enhanced infrared absorption(SEIRA) spectroscopy,attenuated total reflection (ATR) spectroscopy and molecular dynamics (MD),we reveal the assembled C≡N at gold nanofilm exhibits a reduced Stark tuning rate (STR) referring to the vibrational frequency shift in response to electric field comparing with the bulk which was regulated by the electron transfer between S and Au.These findings lead to a deeper understanding of the vibrational Stark effect at the interface and provide guidance for improving the interface electric field theory.