Photocatalytic　bacterial　inactivation　under　visible　light　emerges　as　a　new　alternative　to　control　microbial　contamination　by　utilizing　free　and　renewable　sunlight.　However,　the　exploration　of　highly　effective　and　safe　visible-light-driven　(VLD)　photocatalysts　remains　an　important　step　toward　accessing　this　new　technology.　Herein,　an　eco-friendly　photocatalyst,　namely　Indium　Sulfide　(In2S3),　was　fabricated　through　a　facile　hydrothermal　method　for　VLD　photocatalytic　inactivation　of　bacteria.　The　energy　band　gap　of　the　as-prepared　In2S3　was　measured　as　2.25　eV.　As　expected,　the　obtained　In2S3　photocatalyst　showed　remarkable　inactivation　efficiency　toward　E.　coli　under　fluorescent　tubes　irradiation.　The　photocatalytic　inactivation　kinetic　was　perfectly　fitted　by　a　mathematical　model　for　bacteria　inactivation.　In　addition,　In2S3　exhibited　high　stability　and　could　be　reused.　The　leakage　of　In3+　was　not　significant　and　showed　no　toxic　effect　to　the　bacteria.　Based　on　the　results　of　scavenger　study　and　ESR　technology,　the　dominant　reactive　species　causing　In2S3　VLD　photocatalytic　bacterial　inactivation　were　proposed　as　[rad]O2−,　h+,　H2O2　and　e−,　rather　than　[rad]OH.　The　SEM　study　suggested　that　the　damages　to　the　intracellular　components　occurred　prior　to　the　destruction　of　cell　wall.　This　study　provides　novel　application　of　In2S3　for　VLD　photocatalytic　inactivation　of　bacteria　as　well　as　comprehensive　insight　into　the　inactivation　mechanism.　©　2020　Elsevier　Inc.