Constructing crystalline redox catalyst to achieve efficient CO2 photoreduction reaction in water vapor

Artificial photosynthesis, coupling CO2 photoreduction and water photooxidation reactions, is an important and green means to convert CO2. Compared with traditional multiphasic heterojunctions, monophasic photocatalysts for artificial photosynthesis are still very rare. Here we construct a crystalline overall reaction catalyst, RO-4, by connecting reductive {CuI8} and oxidative {PMo8V6O42} clusters with bridging oxygen atoms, which allow the photogenerated electrons to transfer easily between the redox clusters. Under light irradiation, RO-4 can achieve efficient artificial photosynthesis with a high CO production activity of 20.06 μmol g-1h−1 (>99.5% selectivity) along with O2 release. Furthermore, in situ DRIFTS and DFT calculations uncover the related reaction intermediates and CO2 photoreduction mechanism. This work validates a feasible strategy to engineer monophasic crystalline RO photocatalysts for efficient artificial photosynthetic overall reaction.