Polymerization using coupling reactions yielding conjugation between the building units has been demonstrated to be an effective strategy to reduce the band gap . Conjugated bridging enhances π-electron delocalization yielding to band dispersion, which results in narrowed band gaps. However, high π-electron conjugation of the building monomers is the most fundamental basis to ensure the high conjugation of the constructed 2D lattice. For instance, C=C-containing 2D organic frameworks have been recently synthesized, with pronounced π-delocalization over the entire 2D network . In the light of these experimental advances, using organic monomers with high π-electron conjugation and HOMO-LUMO gaps of 3-4 eV as the building units appears to be an efficient strategy to construct highly conjugated 2D polymers for photocatalysis. Note that the HOMO-LUMO gaps must be chosen larger than the envisaged band gap, as band dispersion will yield smaller band gaps. This effect enhances with the degree of π-conjugation.