We　have　systematically　investigated　the　electronic　structures　and　activation　capacities　of　BiOBr　{001}　facets　with　different　atomic　terminations　by　means　of　DFT　methods.　Our　calculations　reveal　that　oxygen　vacancies　(OVs)　give　a　significant　boost　in　band　edges　of　the　O-terminated　BiOBr　{001}　facets,　and　excess　electrons　induced　by　OVs　could　exceed　the　reduction　potentials　of　high-energy　N-2　intermediates.　Interestingly,　the　Bi-terminated　BiOBr　{001}　facets　may　be　good　candidates　for　photocatalytic　nitrogen　fixation　due　to　the　stronger　activation　ability　of　N-2　molecules　comparing　with　O-terminated　BiOBr　{001}　facets　with　OVs.　Moreover,　the　Bi-terminated　BiOBr　{001}　facets　may　tend　to　yield　NH3　instead　of　N2H4.