Photocatalytic　hydrogen　production,　as　an　ideal　strategy　for　solar-to-fuel　conversion,　remains　the　great　challenges　in　designing　the　highly　efficient　photocatalytic　systems.　Herein,　the　monolayer　HTi2NbO7　nanosheets　with　the　thickness　of　1.65　nm　are　developed　as　photocatalysts　coupled　with　Pt　nanoparticles　for　hydrogen　production　from　water.　The　Pt　nanocluster/HTi2NbO7　nanosheets　prepared　via　an　in　situ　process　showed　the　better　photocatalytic　activity　for　H2　evolution　than　that　obtained　by　a　chemical　reduction.　The　higher　dispersity　and　more　closely　interface　contact　between　the　nanosheets　and　Pt　nanoclusters　would　promote　the　transfer　of　the　photogenerated　carriers.　A　synergistic　photocatalytic　mechanism　for　monolayer　nanosheets　and　Pt　nanocluster　would　be　proposed　to　elucidate　the　high　efficient　hydrogen　production.　©　2020　Elsevier　B.V.