Transition　metal　chalcogenide　quantum　dots　(TMCs　QDs)　constitute　a　crucial　sector　of　semiconductors　on　account　of　large　absorption　coefficient　for　light　harvesting,　peculiar　quantum　confinement　effect,　and　abundant　active　sites　stemming　from　ultra-small　size.　However,　elaborate　and　tunable　modulation　of　ani-sotropic　photoinduced　charge　carriers　over　TMCs　QDs　represents　an　enduring　challenge　in　terms　of　sluggish　charge　transfer　kinetic　and　ultra-short　charge　lifetime　compared　with　nanoparticulate　counterparts,　thereby　rendering　maneuvering　charge　transfer　of　TMCs　QDs　a　tough　issue.　We　herein　conceptually　unlock　the　unanticipated　charge　transport　capability　of　solid-state　non-conductive　poly(diallyl　dimethy-lammonium　chloride)　(PDDA)　for　constructing　cascade　charge　transfer　pathway　over　self-assembled　wide　bandgap　semiconductors　(WBS)/PDDA/TMCs　QDs　multilayered　heterostructures,　by　which　unidirectional　and　accelerated　electron　transfer　from　TMCs　QDs　to　WBS　support　mediums　was　spontaneously　activated,　markedly　boosting　the　charge　separation/migration　efficiency.　The　integrated　roles　of　such　ultrathin　insulating　PDDA　intermediate　layer　as　simultaneous　surface　charge　modifying　agent　and　interfacial　charge　transfer　mediator　have　been　evidenced　to　be　universal.　The　unexpected　electron-withdrawing　capability　of　ultrathin　PDDA　layer　endows　WBS　(SnO2,　TiO2)@PDDA@TMCs　(CdSe,　CdS)　QDs　heterostructures　with　significantly　enhanced　net　efficiency　of　photoactivities　toward　selective　anaerobic　reduction　of　nitroaromatics　to　amino　derivatives　under　visible　light　irradiation.　Our　work　would　feature　a　promising　scope　for　rational　design　of　multifarious　novel　insulating　polymers-based　photosystems　for　solar　energy　conversion.　(C)　2021　Elsevier　Inc.　All　rights　reserved.