The first step to evaluate photocatalytic activity is to compare the band edge alignments with the water redox potentials. Generally, to facilitate overall water splitting, the VBM of the photocatalyst must be lower than the OER potential (-5.67 eV vs. vacuum), while the CBM is required to locate above the HER potential (-4.44 eV vs. vacuum). As illustrated in Figure , 2D CTPAB shows appropriate band edge alignments for overall water splitting, while 2D OTPAB and MTPAB only meet the requirement for the HER process. The band edge distribution tendency of these binary HT-polymers is identical to their corresponding unary counterparts, indicating again the importance of appropriate bridge functionalization.