Visible-Light-Active Titanium Sulfonate Framework for Photocatalytic Organic Synthesis

In this work, the first visible-light-active titanium sulfonate metal-organic framework (denoted as FIR-138) with 2-fold interpenetrated srs topology was synthesized by employing 2,5-dihydroxy-1,4-benzenedisulfonic acid (H4DOBSC) as ligands. The strong chelating coordination ability of the hydroxyl and sulfonate O atoms from H4DOBSC endows the framework of FIR-138 with good stability, while the formation of the Ti-phenolic motif ensures excellent visible light absorption with a bandgap (E-g) of 1.74 eV. More importantly, the extensive titanium active sites within the structure could trap the photogenerated electrons and promote the charge separation effectively, attributed to the excellent visible light photocatalytic performance in organic reaction. FIR-138's capability to harness visible light for photocatalytic reactions presents a promising advancement in the field of Ti-MOF photocatalysts. These results provide valuable insights and open up new avenues for the rational design and synthesis of visible-light-active Ti-MOF photocatalysts.