A　new　photocatalyst,　the　tri-arm　CdS/ZnS　core–shell　nanorod,　is　carefully　designed　for　the　first　time,　where　tri-arm　CdS　nanorods　are　decorated　by　dodecylamine　(DDA)　molecules　and　then　wrapped　in　an　intermittent　ZnS　shell.　The　resultant　photocatalyst　with　a　CdS/ZnS　mole　ratio　of　0.5　(CZS0.5)　presents　a　significantly　improved　H2　evolution　rate　of　726.0　μmol/h　(3　mg　of　catalysts,　equal　to　242.0　mmol/g/h)　in　the　absence　of　co-catalysts,　which　is　currently　the　highest　value　in　CdS-based　catalysts.　The　apparent　quantum　efficiency　of　CZS0.5　reaches　50.61%　at　380　nm.　The　significantly　enhanced　photocatalytic　performance　can　be　attributed　to　a　win–win　situation　between　the　analogous　type-II　mechanism　formed　in　the　CdS/ZnS　heterojunction　and　the　H+　adsorption　resulting　from　the　DDA　molecules.　Due　to　the　analogous　type-II　mechanism,　photogenerated　electrons　are　transferred　from　the　ZnS　shell　to　the　CdS　nanorod.　Owing　to　the　decoration　of　DDA,　many　H+　ions　are　adsorbed　on　CdS.　Thus,　the　photogenerated　electrons　gathered　in　CdS　can　be　captured　quickly　and　in　a　timely　manner　by　the　adsorbed　proton　H+　to　produce　hydrogen,　which　effectively　suppresses　the　recombination　of　photogenerated　electrons　and　holes.　This　study　may　bring　new　insights　for　developing　other　photocatalysts　with　high　performance　by　using　small　organic　molecules.　©　2021　Elsevier　B.V.