Abstract:　Iodine-modified　ZnO　with　oxygen　vacancies　were　synthesized　by　the　solvothermal　method.　The　crystal　structure,　morphology,　optical　properties　and　defects　of　as-prepared　samples　were　characterized　by　XRD,　SEM,　DRS,　XPS　and　ESR.　The　photocatalytic　disinfection　activity　of　I-modified　ZnO　in　the　dark　and　under　visible　light　irradiation　were　investigated　by　the　antibacterial　drop-test　method.　The　results　showed　that　the　iodine　mainly　exists　in　the　form　of　I−　in　the　ZnO.　The　modified　iodine　increases　the　numbers　of　oxygen　vacancies　of　ZnO　as　the　amount　of　iodine　increases.　In　addition,　the　I-ZnO　exhibits　much　higher　antibacterial　activity　than　that　of　pure　ZnO　and　was　stable　during　the　photocatalytic　process.　The　enhanced　antibacterial　activity　of　I-ZnO　is　attributed　to　the　co-operation　of　the　oxygen　vacancies　and　the　iodine　which　promotes　the　separation　of　photo-generated　carriers　and　subsequently　produces　more　ROS　(reactive　oxygen　species).　Graphical　Abstract:　[Figure　not　available:　see　fulltext.].　©　2017,　Springer　Science+Business　Media　B.V.