Fig. 5: Mechanism and DFT calculations.

a A proposed reaction pathway for the photocatalytic CO₂ reduction over MCOF-Ti₆Cu₃. b Proposed mechanism of CO₂ reduction and H₂O oxidation. c Transitions of electron cloud distribution under solar irradiation. d Free-energy profile for the CO₂ reduction and H₂O oxidation pathway over MCOF-Ti₆Cu₃.