Photoactive Metal–Organic Framework and Its Film for Light-Driven Hydrogen Production and Carbon Dioxide Reduction

The design of a new photocatalytic
system and integrating the essential components in a structurally
controlled manner to create artificially photosynthetic systems is
high desirable. By incorporating a photoactive triphenylamine moiety
to assemble a Gd-based metal–organic framework as a heterogeneous
photosensitizer, new artificial systems were constructed for the proton
and carbon dioxide reduction under irradiation. The assembled MOFs
exhibited a one-dimensional metal-oxygen pillar that was connected
together by the depronated TCA3– ligands to form
a three-dimensional noninterpenetrating porous framework. The combining
of proton reduction and/or the carbon dioxide reduction catalysts,
i.e., the Fe-Fe hydrogenase active site models and the Ni­(Cyclam)
complexes, initiated a photoinduced single electron transfer from
its excited state to the substrate. The system exhibited an initial
TOF of 320 h–1 of hydrogen per catalyst and an overall
quantum yield of about 0.21% and is able to reduce carbon dioxide
under irradiation. The deposit of the photoactive Gd-TCA into the
film of an α-Al2O3 plate provided a platform
for the practical applications through prolonging the lifetime of
the artifical system and allowed the easily operated devices being
recyclable as a promising photocatalytic system.