Ag@AgI/Bi-BiOI　(AABB)　three-dimentional　(3D)　nanoarchitectures,　synthesized　by　solvothermal　reaction　and　photoreduction　method,　were　used　as　high–effective　visible　light　driven　(VLD)　photocatalysts　for　the　inactivation　of　Escherichia　coli　K–12　(E.　coli　K–12)　and　were　characterized　by　TEM,　SEM,　XRD,　BET,　XPS　and　DRS.　The　prepared　30%AABB　exhibited　the　best　bacteria　disinfection　efficiency,　and　the　quantity　of　viable　bacteria　could　almost　inactivate　after　being　illuminated　for　18　min.　The　enhanced　photocatalytic　performance　can　be　attributed　to　the　improved　separation　efficiency　of　the　photogenerated　electron–hole　pairs　because　of　its　multivariant　nanoarchitectures　with　simultaneous　electron　transfers　(Bi　→　BiOICBM　→　Ag　→　AgIVBM).　Furthermore,　the　SEM　technology　was　applied　to　certify　the　photocatalytically　lethal　effect　to　E.　coli　K–12　and　the　rupture　of　bacterial　membranes.　In　this　work,　the　antibacterial　mechanism　was　studied　by　employing　Photoluminescence　(PL),　Photoelectrochemical　Techniques,　Electron　Spin　Resonance　(ESR),　and　scavengers　of　different　reactive　species,　revealing　the　pivotal　roles　of　h+,　e−,　and　[rad]O2−　in　the　photocatalytic　process.　This　study　indicated　that　the　fabricated　AABB　photocatalysts　could　be　potentially　utilized　to　disinfect　bacteria　in　water.　©　2016　Elsevier　B.V.