To　enhance　the　separation　efficiency　of　photo-generated　carriers,　a　p–n　junction　photocatalyst　BiOI/NaNbO3　has　been　fabricated　by　a　facile　method.　The　obtained　samples　were　characterized　by　XRD,　SEM,　TEM,　HRTEM,　PL,　N2　sorption–desorption　and　DRS.　DRS　results　showed　that　the　light　absorption　edges　of　BiOI/NaNbO3　hybrids　were　red-shifted　with　the　increase　of　BiOI　content.　The　SEM　and　TEM　images　revealed　that　the　BiOI　was　widely　decorated　over　the　surfaces　of　NaNbO3　cubes.　The　formation　of　p–n　heterojunction　at　their　interfaces　was　proved　by　the　HRTEM　image.　The　visible　light-driven　photocatalytic　activity　was　evaluated　by　the　degradation　of　methylene　blue　(MB)　in　aqueous　solution.　Compared　with　single　NaNbO3　and　BiOI,　the　BiOI/NaNbO3　hybrid　photocatalysts　have　exhibited　significantly　enhanced　activities.　Meanwhile,　the　mass　ratio　of　BiOI/NaNbO3　displayed　important　influence　on　the　MB　degradation.　The　hybrid　photocatalyst　with　BiOI　content　of　40%　performed　the　optimal　activity.　This　activity　enhancement　should　be　attributed　to　the　strong　visible　light　absorption,　the　high　migration　and　separation　efficiency　of　photo-induced　carriers.　The　photocurrent　and　PL　measurements　confirmed　that　the　interfacial　charge　separation　efficiency　was　greatly　improved　by　coupling　BiOI　with　NaNbO3.　Controlled　experiments　proved　that　the　degradation　of　pollutants　was　mainly　attributed　to　the　oxidizing　ability　of　the　generated　holes　(h+),　·O2−,　and　·OH　radicals.　©　2017