Photocatalytic　N-2　fixation　(PNF)　provides　a　low-cost　route　to　generate　ammonia.　The　poor　conversion　efficiency　from　photon　to　ammonia　seriously　hinders　the　step　forward　because　of　the　low　concentration　of　N-2　molecules.　Herein,　we　demonstrate　a　photocatalyst　with　surface　oxygen　vacancies　(Vo)　and　a　F　modified　surface　to　facilitate　N-2　adsorption　and　activation　on　the　surface　of　catalysts.　The　Vo　site　promotes　the　chemical　adsorption　of　N-2,　electron　transfer　from　catalyst　to　N-2.　F　modification　switches　the　TiO2　surface　properties　from　hydrophilic　to　aerophilic,　thus　facilitating　the　adsorption　of　N-2.　Meanwhile,　the　hydrogen　reduction　reaction　(HER)　is　sup-pressed,　as　protons　hard　to　adsorb　on　F　capped　surfaces.　The　optimal　NH3　production　rate　can　reach　206　mu　molh(-1)g(-1),　which　is　similar　to　9　times　higher　than　that　of　pure　TiO2　nanoparticles　(similar　to　23　mu　molh(-1)g(-1)).　This　report　provides　a　potential　strategy　to　overcome　mass　transfer　limitation　and　achieve　a　high　conversion　efficiency　in　PNF.