Metal-organic frameworks (MOFs) are emerging materials for electro- and photo-chemical applications, where an understanding of the underlying charge-transfer (CT) process will facilitate designing new materials. However, the involvement of counterions in traditional electrochemical experiments complicates the probe on the role of various components during a CT event. A CT reaction between photoexcited MOF linker and a node-anchored ferrocene, within mesoporous framework NU-1000, was spectroscopically probed without the involvement of electrolyte based counterions. Dielectric dependent CT kinetics indicate that the process involves a high reorganization energy that is required to polarize the node bound hydroxyl/aqua ligands. The findings have clear implication on the design of MOF-based electrocatalysis and photoelectrochemical devices.
Bibliographical noteFunding Information:
We thank SIUC for the startup support and IMAGE center (CHE0959568) for the SEM-EDS data. We also thank Advanced Coal & Energy Research Center for partial support through Energy Boost Seed Grant. P.D. acknowledges Ralph E. Powe Junior Faculty Enhancement Award, administered by ORAU. A.V.W. acknowledges NSF-REU fellowship (DMR-1461255). J.P. acknowledges JSPS KAKENHI Grant-in-Aid for Research Activity Start-up Grant Number 17H06791 and Dr. Yasunari Tamai and Kazuki Yoshitaka for their assistance on fs-TA measurements. We thank Dr. Chung-Wei Kung, North-western University, for DRIFTs data.
© 2018 American Chemical Society.