An alternative route has been suggested for layered, so-called electron donor-acceptor covalent-organic frameworks, where electron-donating and -accepting building blocks are coupled in a bicontinuous manner. Such heterojunction is conducive to transfer photoinduced charge carriers between two half electrodes. Here, we theoretically demonstrate that the same capability can be achieved if the heterojunction is realized in a single plane as proposed in the title compounds, resulting in a single-material high quantum efficiency photocatalyst by coupling Band N-HTs into a honeycomb-kagome structure with alternating distribution of heteroatoms. We confirm their stability and photocatalytic activity by employing first principles calculations. The donor-acceptor coupling effect, band edge alignments, light absorbance and the carrier mobilities are rationalized by analyzing the band structure. Finally, the thermodynamic HER and OER processes are simulated to understand the potentials of applying these 2D polymers for effective solar-driven water splitting.