Flash
Metal-organic framework-based photo-electrochemical cells

Photo-active metal-organic frameworks (MOFs) are considered as promising materials for the study of photo-electrochemical cells (PECs). They can be utilized as porous, high surface area scaffolds for the assembly of molecular chromophores atop semiconducting electrodes. Usually however, the lack of prominent electronic interactions between adjacent MOF-installed chromophores impedes the development of PECs based solely on MOFs (without the use of a semiconducting electrode, e.g. TiO₂). Here we demonstrate that unlike standard semiconducting photo-electrodes, the photo-electrochemical behavior of a MOF-based electrode can be switched from photo-anodic to photo-cathodic by an appropriate choice of redox mediators in the electrolyte. Additionally, we found that the MOF-based photo-cathode is capable of photo-electrocatalytic H₂ production. Thus, these findings have clear impact on the design of MOF-based PECs for solar fuel generation.