A　series　of　dehydrated　MoS2/UiO-66(SH)2　(MS/UiS)　composites　has　been　prepared　as　photocatalysts　for　N2　fixation.　Typically,　10%　MS/UiS　exhibits　the　best　performance　with　an　NH4+　yield　rate　of　54.08　μmolg−1h−1.　15N　isotope　test　confirmed　that　the　sample　10%　MS/UiS　was　most　effective　for　reducing　N2　to　ammonia.　Such　enhanced　activity　was　due　to　the　presence　of　abundant　unsaturated　Zr　and　Mo　sites　which　would　synergistically　promote　the　adsorption　and　activation　of　N2.　The　photogenerated　electrons　would　transfer　to　the　unsaturated　Zr-O　clusters　while　part　of　photogenerated　electrons　at　the　interface　migrate　to　MS　via　MoVI-O　interactions　between　MS　and　UiS.　These　two　electron　transfer　pathways　effectively　promote　the　separation　of　photogenerated　carriers.　The　activated　N2　is　reduced　to　ammonia　by　the　synergistic　effect　of　protonated　hydrogen　and　photogenerated　electrons.　Finally,　a　possible　N2　fixation　mechanism　is　proposed　which　emphasizes　the　significant　roles　of　nitrogen　activation　and　interface　interaction　in　composites　photocatalyst　for　improving　photocatalytic　performance.　©　2023