The　tightness　of　pi-pi　stacking　in　supramolecular　organic　semiconductors　plays　a　crucial　role　in　governing　the　spatial　separation　and　migration　dynamics　of　photogenerated　charge　carriers,　ultimately　determining　their　photocatalytic　performance.　To　achieve　close　pi-pi　stacking,　the　suitable　design　of　molecular　structure　is　essential.　Therefore,　two　isomers　of　pyridine　carboxylic　acid-modified　perylene　monoimide　(PMI)　were　designed　and　synthesized,　namely　PM5A　and　PM6A.　In　aqueous　solution,　these　molecules　self-assemble　into　aggregates,　which　exhibit　distinct　stacking　properties　and　optical　characteristics.　Upon　photoexcitation,　the　loose　pi-pi　stacking　of　PM5A　favors　the　generation　of　charge-transfer　excitons　(CTEs)　over　charge-separation　excitons　(CSEs).　In　contrast,　PM6A,　stabilized　by　intermolecular　hydrogen　bonds　and　possessing　close　pi-pi　stacking,　undergoes　efficient　charge　separation　(CS)　to　produce　CSEs　within　4.5　picoseconds.　When　incorporated　into　metal-insulator-semiconductor　(MIS)　photosystems　with　polyvinylpyrrolidone　(PVP)-capped　Pt,　the　Pt/PVP/PM6A　system　demonstrates　a　hydrogen　evolution　rate　(HER)　of　8100　mu　mol　g(-1)　h(-1),　nearly　five　times　higher　than　that　of　the　Pt/PVP/PM5A　system.　Additionally,　the　maximum　apparent　quantum　efficiency　(AQE)　reaches　approximately　2.1%　under　irradiation　with　light　of　a　single　wavelength　of　lambda　=　425　nm.