Charge-Transfer within Zr-Based Metal–Organic Framework: The Role of Polar Node

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.