Unidirectional/Bidirectional Electron Transfer at the Au/TiO2 Interface Operando Tracked by SERS Spectra from Au and TiO2

Although it is well-known that the size can influence the surface plasmon resonance property of coinage metals and the electronic state of the Mott-Schottky junction formed at the metal/semiconductor interface, insights into how the size can be exploited to optimize the photocatalytic activity and selectivity of metal/semiconductor composites are lacking. Here we utilize operando SERS spectroscopy to identify the size effect on the electron-transfer dynamics and the direction at the Au/TiO2 interface. This effect was characterized by the photocatalytic reduction sites of p-nitrothiophenol, which were self-tracked with the SERS spectra from Au nanoparticle and inverse-opal structured TiO2, respectively. The size-dependent unidirectional/bidirectional transfer of photoinduced electrons at the Au/TiO2 interface was revealed by operando SERS spectroscopy, which enables the rational tuning of the reduction selectivity.

Automated summary

This study used operando SERS spectroscopy to investigate the electron transfer dynamics and direction at the Au/TiO2 interface, revealing the size-dependent unidirectional/bidirectional transfer of photoinduced electrons and enabling rational tuning of reduction selectivity in metal/semiconductor composites.