Well-organized　water　splitting　semiconducting　photocatalyst　is　an　important　concept,　but　stimulating　aimed　at　decisive　energy　and　environmental　emergencies.　In　this　context,　visible　light-based　photocatalytic　water　splitting　with　low-dimensional　semiconducting　materials　is　proposed　to　produce　sustainable　energy.　Here　we　optimized　the　sequential　of　organic　electron-rich　heterocyclic　monomer　namely　benzothiadiazole　(BTD)　quenched　within　polymeric　carbon　nitride　(PCN)　semiconductor　via　copolymerization,　thereby　assembling　a　sanctum　of　donor　-n-acceptor　(D　-n-A)　photocatalysts.　The　selection　of　BTD　is　based　on　the　benzene　ring,　which　consequently　anticipating　a　n　cross-linker　unit　for　hydrogen　and　oxygen　evolution.　A　hydrogen　evolution　rates　(HER)　of　88.2　mu　mol/h　for　pristine　PCN　and　744.2　mu　mol/h　for　PCN-BTD008　(eight　times　higher　than　pure　PCN)　are　observed.　Additionally,　a　remarkable　apparent　quantum　yield　(AQY)　of　about　58.6%　at　420　nm　has　been　observed　for　PCN-BTD008.　Likewise,　the　oxygen　evolution　rate　(OER)　data　reflect　the　generation　of　0.2　mu　mol/h1　(visible)　and　1.6　mu　mol/h1　(non-visible)　for　pure　PCN.　Though,　OER　of　PCN-BTD008　is　found　to　be　2.2　mu　mol/h1　(visible)　and　14.8　mu　mol/h1　(non　visible),　which　are　economically　better　than　pure　PCN.　As　such,　the　results　show　an　important　step　toward　modifying　the　design　and　explain　a　vital　part　of　the　D　-n-A　scheme　at　a　balanced　theme　for　fruitful　photocatalysts　intended　for　future　demand.　(c)　2022　Elsevier　Inc.　All　rights　reserved.