Design of Crystalline Reduction–Oxidation Cluster-Based Catalysts for Artificial Photosynthesis

Metal
cluster-based compounds have difficulty finishing the photocatalytic
carbon dioxide reduction reaction (CO2RR) and water oxidation
reaction (WOR) simultaneously because of the big challenge in realizing
the coexistence of independently and synergistically reductive and
oxidative active sites in one compound. Herein, we elaborately designed
and synthesized one kind of crystalline reduction–oxidation
(RO) cluster-based catalysts connecting reductive {M3L8(H2O)2} (M = Zn, Co, and Ni for RO-1, 2, 3 respectively) cluster and oxidative {PMo9V7O44} cluster through a single oxygen
atom bridge to achieve artificial photosynthesis successfully. These
clusters can all photocatalyze CO2-to-CO and H2O-to-O2 reactions simultaneously, of which the CO yield
of RO-1 is 13.8 μmol/g·h, and the selectivity
is nearly 100%. Density functional theory calculations reveal that
the concomitantly catalytically reductive and oxidative active sites
(for CO2RR and WOR, respectively) and the effective electron
transfer between the sites in these RO photocatalysts
are the key factors to complete the overall photosynthesis.