Solar-driven　syngas　production　by　CO2　reduction　provides　a　sustainable　strategy　to　produce　renewable　feedstocks.　However,　this　promising　reaction　often　suffers　from　tough　CO2　activation,　sluggish　oxidative　half-reaction　kinetics　and　undesired　by-products.　Herein,　we　report　a　function-oriented　strategy　of　deliberately　constructing　black　phosphorus　quantum　dots-ZnIn2S4　(BP/ZIS)　heterostructures　for　solar-driven　CO2　reduction　to　syngas,　paired　with　selectively　oxidative　C-N　bond　formation,　in　one　redox　cycle.　The　optimal　BP/ZIS　heterostructure　features　the　enhanced　charge-carrier　separation　and　enriched　active　sites　for　cooperatively　photocatalytic　syngas　production　with　a　tunable　ratio　of　CO/H-2　and　efficient　oxidation　of　amines　to　imines　with　high　conversion　and　selectivity.　This　prominent　catalytic　performance　arises　from　the　efficient　electronic　coupling　between　black　phosphorus　quantum　dots　and　ZnIn2S4,　as　well　as　the　optimized　adsorption　strength　for　key　reaction　intermediates,　as　supported　by　both　experimental　and　theoretical　investigations.　We　also　demonstrate　a　synergistic　interplay　between　CO2　reduction　and　amine　dehydrogenation　oxidation,　rather　than　simply　collecting　these　two　single　half-reactions　in　this　dual-functional　photoredox　system.