Donor-acceptor covalent organic frameworks of nickel(II) porphyrin for selective and efficient CO2 reduction into CO

Donor-acceptor two-dimensional covalent organic frameworks PD- COF-23 and PD-COF-23-Ni are constructed, and applied for selective CO2 redution with 20.9 µmol g−1 h−1 and 40.0 µmol g−1 h−1 CO conversion, respectively, in the absence of any additional photosensitizers and noble metal co-catalytst within an operation time of 25 h. The mutlilayer nanosheet structure, efficient charge separation and transport, and internal reductive quenching cycle of NiTAPP fragments for PD-COF-23-Ni lead to its higher photocatalytic efficiency than that of PD-COF-23.