Here,　1D　bis(N-carboxymethyl)　peryleneimide　(H2PDI),　0D　1,6,7,12-tetrachloro-bis(N-carboxymethyl)　peryleneimide　(4Cl-H2PDI),　and　2D　4Cl-H2PDI/graphene　quantum　dot　(4Cl-H2PDI/GQD)　nanostructures　are　synthesized　and　carefully　analyzed.　The　effect　of　bay-/end-substitution　and　S-scheme　heterojunction　of　PDI-based　materials　as　main　catalysts　on　the　photocatalytic　H2O2　evolution　is　first　studied　through　the　oxygen　reduction　reaction　(ORR).　Under　the　visible-light　irradiation　(＞　420　nm),　4Cl-H2PDI　and　4Cl-H2PDI/GQD　as　photocatalysts　exhibit　the　∼7　and　∼16　times　H2O2　evolution　rate　than　H2PDI　(1059.6　vs.　2484.0　vs.　160.0　µM　g−1　h−1),　respectively.　The　systematical　experiments　reveal　that　4Cl-H2PDI　and　4Cl-H2PDI/GQD　should　prefer　a　two-step　single-electron　ORR　process,　while　H2PDI　may　involve　a　4e‒　water　oxidation　and　one-step　2e‒　ORR　process.　Further　experiments　confirm　that　the　bay-substitution　and　GQD　doping　of　H2PDI　can　promote　the　generation,　transportation,　and　separation　of　photogenerated　electrons　and　holes,　and　prolong　the　carrier　lifetime.　This　work　provides　insight　into　PDI-based　photocatalytic　H2O2　production.　©　2024