Tunable　and　efficacious　modulation　of　photo-induced　charge　carrier　separation　and　transfer　in　photoelectrochemical　(PEC)　cell　for　solar　water　splitting　constitute　a　central　challenge.　Herein,　high-efficiency　plasmon-induced　hot　carriers　transfer　channel　has　been　rationally　and　progressively　constructed　by　judicious　layer-by-layer　assembly　of　graphene　quantum　dots　(GQDs)　and　plasmonic　metal　nanocrystals　(Ag　NCs)　on　the　one-dimensional　semiconductor　(TiO2　nanorods　arrays,　TiO2　NRs)　framework,　resulting　in　a　well-defined　spatially　multilayered　photoanode.　The　unique　and　alternate　integration　of　GQDs　with　Ag　NCs　on　the　TiO2　NRs　is　closely　associated　with　charge　transfer　behaviors.　It　was　unveiled　that　Ag　NCs　in　situ　integrated　in　the　multilayered　film　enable　hot　electron　generation,　and　simultaneously　play　a　crucial　role　in　finely　relaying　electron　transfer　from　GQDs　to　TiO2.　This　gives　rise　to　significantly　enhanced　solar-powered　PEC　water　splitting　performances　of　TiO2　NRs@Ag@GQDs　ternary　multilayered　heterostructure,　which　far　surpasses　the　corresponding　binary　and　single　counterparts.　Consequently,　intrinsic　correlation　of　metal　NCs　with　GQDs　in　terms　of　charge　transport　was　for　the　first　time　clarified.　©　The　Royal　Society　of　Chemistry.