It　is　very　attractive　to　find　a　cheap　and　efficient　cocatalyst　for　enhancing　the　H2　generation　of　graphitic　carbon　nitride　(CN)　under　visible　light.　To　achieve　that,　we　proposed　a　novel　two-step　method　to　deposit　sub-10　nm　metallic　Ni2P　particles　on　the　surface　of　CN　sheets　for　a　maximized　interfacial　contact.　Characteristic　results　confirmed　the　establishment　of　ohmic　heterojunction　upon　Ni2P-modification　of　CN,　which　deemed　to　be　an　effective　measure　to　alleviate　photo-charges　recombination.　In　addition　to　facilitating　spatial　separation　of　charges,　Ni2P　could　also　enhance　the　optical　properties　of　CN　while　reducing　its　impedance　for　interfacial　electron　shuttling.　Better　still,　the　P-end　of　Ni2P　is　highly　electronegative,　offering　desirable　H+-capturing　capability　for　enhanced　H2　generation.　These　give　rise　to　an　improved　H2　production　of　Ni2P/CN　composite,　optimally　at　645.3　μmol　g−1·h−1　as　compared　to　immeasurable　H2　yielded　by　the　pristine　CN.　Such　photocatalytic　performance　is　even　comparable　to　the　Pt-modified　CN　photocatalyst　(640.6　μmol　g−1·h−1).　In　recyclability　test,　a　notable　activity　suppression　of　33.17%　was　recorded　after　four　reaction　cycles.　This　can　be　ascribed　to　the　pronounced　photo-corrosion　of　the　Ni2P　cocatalyst　during　photoreaction.　Nonetheless,　a　remarkably　high　H2　generation　(1328.6　μmol　g−1　in　3　h)　was　still　attained　at　4th　cycle.　This　justifies　the　effectiveness　of　our　synthesized　Ni2P　cocatalyst　in　enhancing　H2　generation　of　CN　under　visible　light　irradiation.　©　2023　Elsevier　Ltd