Hydrogen　peroxide　(H2O2)　is　recognized　as　an　environmentally　benign　oxidant　with　widespread　applications　in　the　water　treatment　and　disinfection　industry.　However,　conventional　anthraquinone-based　methods　for　H2O2　production　are　characterized　by　high　energy　consumption　and　the　generation　of　hazardous　byproducts,　necessitating　the　development　of　more　sustainable　alternatives.　In　this　study,　we　present　an　S-scheme　heterojunction　constructed　from　MnIn2S4　and　a　covalent　organic　framework　(COF),　which　exhibits　an　enhanced　internal　electric　field　(IEF)　to　facilitate　efficient　photocatalytic　H2O2　synthesis　without　the　use　of　sacrificial　agents.　This　heterojunction　demonstrates　superior　charge　separation　and　transfer　capabilities,　achieving　a　remarkably　high　H2O2　production　rate　of　4007　μmol·g−1·h−1　under　visible　light　irradiation　and　an　unprecedented　apparent　quantum　yield　of　7.14%.　Mechanistic　investigations　reveal　that　the　S-scheme　charge　transfer　pathway　optimizes　redox　reactions,　while　the　photosynthesized　H2O2　and　its　precursors,　superoxide　radicals,　synergistically　disrupt　bacterial　defense　mechanisms　by　inhibiting　key　antioxidant　enzymes　(e.g.,　superoxide　dismutase,　catalase,　and　glutathione)　and　impairing　energy　metabolism,　ultimately　leading　to　bacterial　cell　death.　Notably,　the　optimal　sample　exhibits　sustained　performance　in　diverse　real　water　matrices,　including　river　and　seawater,　under　natural　sunlight　conditions,　with　negligible　effluent　toxicity.　This　work　provides　a　sustainable　strategy　for　H2O2　production　and　water　purification,　offering　insights　into　the　rational　design　of　advanced　photocatalytic　materials　for　the　water　disinfection　industry.　©　2025　Elsevier　Ltd