The　creation　of　active　sites　on　semiconductor　catalysts　for　the　adsorption　of　N2　and　dissociation　of　nonpolar　N≡N　bond　is　a　key　issue　for　photocatalytic　N2　reduction　reaction　(PNRR).　According　to　density　function　theory　calculation　on　MoS2,　the　Mo　rather　than　the　S　edge　sites　are　active,　and　those　on　basal　planes　not.　It　is　disclosed　that　Mn　doping　is　an　effective　way　to　boost　the　activity　of　MoS2　by　modifying　the　edge　sites.　The　Mn-modified　MoS2　has　higher　exposure　of　Mo　edge　sites　due　to　the　formation　of　S　vacancies.　It　is　noted　that　the　activity　of　original　Mo　edge　sites　remains　unaltered,　while　the　inertness　of　S　edge　sites　for　N2　adsorption　moderated.　Furthermore,　the　injection　of　electrons　into　the　N≡N　bond　is　promoted,　leading　to　lowering　of　energy　barrier　for　N2　reduction.　Finally,　through　a　simple　hydrothermal　method　we　prepared　MoS2　that　is　rich　in　edge　sides　at　the　basal　plane　by　Mn　doping.　High　ammonia　production　rate　of　up　to　213.2　μmol　g−1h−1　is　achieved,　which　is　5.3　times　that　of　pristine　MoS2　and　superior　to　most　of　the　reported　MoS2-based　photocatalysts　in　the　absence　of　sacrificial　agent.　©　2022