Abstract
2D catalysts combined with single atom sites are promising candidates to promote CO2 reduction performance, but the ability to target stable materials with distinct structure still remains challenging. Herein, a series of single metal atoms anchored 2D metal-organic framework nanosheets (MOF-NS-M) with visualized and well-ordered mesoporous structures are fabricated and exhibit enhanced CO2 reduction activity and selectivity with the assistance of visible-light. Encouragingly, the CO Faradaic efficiency of MOF-NS-Co exceeds 90% in a wide potential window of -0.5 to -1.0 V versus RHE and reaches 98.7% with 100 mV positive shift compared with the result measured under dark. The catalytic kinetics studies show a fast initial electron transfer to CO2 to form *COO-, thanks to the sufficient exposed active sites resulting from the nanosheet nature and adjusted electron transfer pathway caused by the porphyrin photoswitch.