A　Z-scheme　heterojunction　polyhedral-shaped　BiOIO3/MIL-53(Fe)　photocatalyst　is　prepared　by　a　solvothermal　method.　The　samples　are　characterized　by　XRD,　XPS,　SEM,　TEM,　FT-IR,　UV-vis,　PL,　and　other　material　characterization　analysis　methods.　The　photocatalytic　performance　of　photocatalysts　is　studied　for　removal　of　vapor-phase　mercury　(Hg0)　under　visiblelight　irradiation.　The　results　suggest　that　the　Hg0　removal　efficiency　of　the　BiOIO3/MIL-53(Fe)　composite　is　significantly　improved　compared　with　that　of　MIL-53(Fe).　When　the　molar　ratio　of　BiOIO3　and　MIL-53(Fe)　is　2:1,　the　BiOIO3/MIL-53(Fe)　composite　photocatalyst　exhibits　the　best　Hg0　removal　efficiency,　reaching　74.19%.　BiOIO3　and　MIL-53(Fe)　form　a　Z-scheme　heterojunction　with　a　suitable　energy　band　structure,　which　results　in　the　effective　separation　of　photoinduced　electron-hole　pairs　and　delays　their　recombination.　Finally,　the　photocatalytic　oxidation　mechanism　of　Hg0　by　the　BiOIO3/MIL-53(Fe)　composite　is　proposed,　which　paves　the　way　for　the　study　of　the　built-in　electric　field　and　electron　transport　channels　between　binary　photocatalyst　materials.　©　2021　American　Chemical　Society.