| Abstract: | We report an ultrafast spectroscopy investigation that addresses the subtle location effect in a prototypical semiconductor-MOF hybrid system with TiO\begin{document}$_2$\end{document} nanoparticles being incorporated inside or supported onto Cu\begin{document}$_3$\end{document}(BTC)\begin{document}$_2$\end{document}, denoted as TiO\begin{document}$_2$\end{document}@Cu\begin{document}$_3$\end{document}(BTC)\begin{document}$_2$\end{document} and TiO\begin{document}$_2$\end{document}/Cu\begin{document}$_3$\end{document}(BTC)\begin{document}$_2$\end{document}, respectively. By tracking in real time the interface electron dynamics in the hybrid system, we find that the interface states formed between TiO\begin{document}$_2$\end{document} and Cu\begin{document}$_3$\end{document}(BTC)\begin{document}$_2$\end{document} can act as an effective relay for electron transfer, whose efficiency rests on the relative location of the two components. It is such a subtle location effect that brings on difference in photocatalytic CO\begin{document}$_2$\end{document} reduction using the two semiconductor-MOF hybrids. The mechanistic understanding of the involved interface electron-transfer behavior and effect opens a helpful perspective for rational design of MOF-based hybrid systems for photoelectrochemical applications. |
