CH-π interaction boosts photocatalytic CO2 reduction activity in a noble-metal-free system with a molecular cobalt catalyst anchored on carbon nitride

The construction of efficient noble-metal-free systems for visible-light-driven CO2 reduction still remains a key challenge. Here we report an efficient molecular hybrid system composed of a Co-PYN5 catalyst that contains a pyrene functionality that anchors on g-C3N4 dye surface via CH-π interactions. This hybrid material achieves high TONs and TOFs for visible light reduction of CO2 to CO of 533 and 95 h-1, that are within the best reported up to now. The exceptional performance is rationalized in terms of the electronic coupling that takes place with the π-system of the pyrene group with both the g-C3N4 surface and the Co-pyridyl moiety of the catalysts.