The　construction　of　layered　covalent　carbon　nitride　polymers　based　on　tri-s-triazine　units　has　been　achieved　by　using　nucleobases　(adenine,　guanine,　cytosine,　thymine　and　uracil)　and　urea　to　establish　a　two-dimensional　semiconducting　structure　that　allows　band-gap　engineering　applications.　This　biomolecule-derived　binary　carbon　nitride　polymer　enables　the　generation　of　energized　charge　carrier　with　light-irradiation　to　induce　photoredox　reactions　for　stable　hydrogen　production　and　heterogeneous　organosynthesis　of　C-O,　C-C,　C-N　and　N-N　bonds,　which　may　enrich　discussion　on　chemical　reactions　in　prebiotic　conditions　by　taking　account　of　the　photoredox　function　of　conjugated　carbonitride　semiconductors　that　have　long　been　considered　to　be　stable　HCN-derived　organic　macromolecules　in　space.