Synergetic effect of H+ adsorption and ethylene functional groups of covalent organic frameworks on the CO2 photoreduction in aqueous solution.

We prepare a novel COF for CO2 photoreduction with 99.9% CO selectivity in aqueous solution without a cocatalyst. DFT shows that the preferential adsorption of H+ on the COF results in increased CO2 adsorption energy providing an anchoring site of CO2, and with the cooperation of an ethylene group, CO2 reduction is triggered.