High　efficiency　and　selectivity　is　significant　for　photocatalytic　organic　transformation.　In　this　work,　the　efficient　photocatalytic　reduction　of　nitrobenzene　into　aniline　is　achieved　on　non-noble　metal　thickness-tunable　bismuth　molybdate　nanosheets　prepared　by　the　simple　hydrothermal　reaction.　The　photocatalytic　activity　of　Bi2MoO6　strongly　depends　on　the　nanosheet　thickness.　The　Bi2MoO6　monolayer　displays　remarkably　enhanced　photocatalytic　activity　for　selective　reduction　of　nitrobenzene　than　bilayer,　multilayers　and　bulk　Bi2MoO6　due　to　the　unique　properties　of　2D　materials　with　the　large　fraction　of　surface　atoms　and　the　ultrafast　charge　separation.　The　obtained　conversion　rate　of　487.5　mu　mol　g(-1.)h(-1)　(　＞　95%　conversion　and　＞　99%　selectivity　within　60　min　reaction)　on　Bi2MoO6　monolayers　is　5　times　higher　than　that　of　Bi2MoO6　bulk,　far　exceeding　most　of　common　photocatalysts　up　to　date.　This　work　provides　a　thickness　dependent　nanosheet　concept　in　the　design　of　newly　highly　efficient　catalysts　for　the　photocatalytic　reduction　conversion　of　nitroarenes　to　anilines.