Direct Synthesis of Topology-Controlled BODIPY and CO-Based Zirconium Metal-Organic Frameworks for Efficient Photocatalytic CO Reduction.

Boron dipyrromethene (BODIPY)-based zirconium metal-organic frameworks (Zr-MOFs) possess strong light-harvesting capabilities and great potential for artificial photosynthesis without the use of sacrificial reagents. However, their direct preparation has not yet been achieved due to challenges in synthesizing suitable ligands. Herein, we reported the first successful direct synthesis of BODIPY-based Zr-MOFs, utilizing CO as a feedstock. By controlling synthetic conditions, we successfully obtained two distinct Zr-MOFs. The first, CO-Zr-DEPB, exhibits a face-centered cubic (fcu) topology based on a Zr(μ-O)(μ-OH) node, while the second, CO-Zr-DEPB, features a hexagonal closed packed (hcp) topology, structured around a Zr(μ-O)(μ-OH)(μ-OH) node. Both MOFs demonstrated excellent crystallinity, as verified through powder X-ray diffraction and high-resolution transmission electron microscopy analyses. These MOF catalysts displayed suitable photocatalytic redox potentials for the reduction of CO to CO using HO as the electron donor in the absence of co-catalyst or toxic sacrificial reagent. Under light irradiation, CO-Zr-DEPB and CO-Zr-DEPB offered high CO yields of 16.72 and 13.91 μmol g h, respectively, with nearly 100 % selectivity. CO uptake and photoelectrochemical experiments revealed key insights into the mechanisms driving the different catalytic activities of the two MOFs. These BODIPY and CO-based, light-responsive Zr-MOFs represent a promising platform for the development of efficient photocatalysts.