Utilizing　photocatalytic　techniques　to　selectively　or　non-selectively　oxidize　organics　to　target　products　represents　a　promising　and　sustainable　way　to　increase　the　supply　of　energy　and　chemical　feedstocks,　and　solve　environmental　pollution.　However,　photoredox　reactions　inevitably　suffer　from　rapid　charge　recombination,　sluggish　charge　transfer　kinetics,　and　scarcity　of　catalytically　active　sites.　Herein,　we　conceptually　demonstrate　the　construction　of　a　spatially　unidirectional　charge　transfer　channel　over　metal@polymer/semiconductor　heterostructured　photosystems　which　are　elaborately　designed　by　a　polymer　ligand-triggered　self-assembly　strategy.　To　this　end,　monodisperse　tailor-made　non-conjugated　insulating　poly(diallyldimethylammonium　chloride)　(PDDA)-capped　metal　(M:　Au,　Pd,　Pt)　nanocrystals　(NCs)　are　controllably　and　uniformly　anchored　on　the　transition　metal　chalcogenides　(TMCs:　CdS,　Zn0.5Cd0.5S)　via　molecular　interactions.　We　found　that　electrons　photoexcited　over　TMCs　can　be　unidirectionally　migrated　to　the　closely　integrated　metal@PDDA　NCs　via　the　ultra-thin　PDDA　interim　layer　capped　on　the　metal　NC　surface,　wherein　the　metal　core　acts　as　a　Schottky-type　electron-trapping　reservoir　and　the　PDDA　ligand　functions　as　an　intermediate　charge　transport　mediator　to　relay　the　directional　electron　transfer　from　TMC　substrates　to　the　metal　core　that　serves　as　the　ultimate　electron　trap,　hence　resulting　in　the　considerably　enhanced　charge　separation/migration.　These　charge　transport　characteristics　endow　the　self-assembled　M@PDDA/TMC　heterostructures　with　substantially　improved　photoactivities　toward　selective　oxidation　of　aromatic　alcohols　to　aldehydes　under　visible　light　irradiation.　Moreover,　we　ascertain　that　such　a　non-conjugated　insulating　polymer　dominated　cascade　charge　transfer　pathway　is　universal.　Our　work　would　inspire　new　ideas　to　strategically　mediate　interfacial　charge　transport　via　an　insulating　polymer　for　solar-driven　organic　transformation.　©　2023　The　Royal　Society　of　Chemistry.