Metal-Organic Framework Photosensitized TiO₂ Co-catalyst: A Facile Strategy to Achieve a High Efficiency...

A 3D metal-organic framework (ADA-Cd=[Cd₂ L₂ (DMF)₂ ]⋅3 H₂ O where H₂ L is (2E,2'E)-3,3'-(anthracene-9,10-diyl)diacrylic acid) constructed from diacrylate substituted anthracene, sharing structural characteristics with some frequently employed anthraquinone-type dye sensitizers, was introduced as an effective sensitizer for anatase TiO₂ to achieve enhanced visible light photocatalytic performance. A facile mechanical mixing procedure was adopted to prepare the co-catalyst denoted as ADA-Cd/TiO₂ , which showed enhanced photodegradation ability, as well as sustainability, towards several dyes under visible light irradiation. Mechanistic studies revealed that ADA-Cd acted as the antenna to harvest visible light energy, generating excited electrons, which were injected to the conduction band (CB) of TiO₂ , facilitating the separation efficiency of charge carriers. As suggested by the results of control experiments, combined with the corresponding redox potential of possible oxidative species, ^. O₂^- , generated from the oxygen of ambient air at the CB of TiO₂ was believed to play a dominant role over ^. OH and h⁺ . UV/Vis and photoluminescence technologies were adopted to monitor the generation of ^. O₂^- and ^. OH, respectively. This work presents a facile strategy to achieve a visible light photocatalyst with enhanced catalytic activity and sustainability; the simplicity, efficiency, and stability of this strategy may provide a promising way to achieve environmental remediation.