Precise　tuning　of　photoinduced　charge　separation　and　transport　has　been　an　enduringly　central　issue　in　photocatalysis　but　has　met　with　limited　success.　In　particular,　the　controllable,　accurate　and　simultaneous　modulation　on　the　charge　(electrons/holes)　transfer　pathway　in　photocatalytic　selective　organic　transformations　has　not　yet　been　achieved.　Herein,　as　a　proof-of-principle　demonstration,　we　report　the　fine　tuning　of　charge　separation/migration　by　smartly　constructing　spatially　separated　charge　transport　channels　over　diverse　metal/transition　metal　chalcogenide　[(M/TMC),　M　=　Au,　Ag,　Pd,　TMCs　=　ZnIn2S4,　CdIn2S4,　In2S3,　and　CdS]　heterostructure　photosystems,　which　were　elaborately　crafted　by　an　efficient　surface　ligand-triggered　electrostatic　self-assembly.　Accordingly,　tailor-made　positively　charged　branched　poly(ethylene　imine)　(bPEI)-capped　metal　nanocrystals　(NCs)　were　controllably　and　uniformly　anchored　on　the　two-dimensional　(2D)　TMC　nanosheet　(NS)　framework,　resulting　in　well-defined　metal/TMC　heterostructures.　We　found　that　electrons　photoexcited　over　TMC　NSs　could　be　spontaneously,　smoothly　and　unidirectionally　migrated　to　closely　integrated　metal@bPEI　NCs,　wherein　the　metal　core　acts　as　a　Schottky-type　electron-trapping　reservoir　and　bPEI　ligand　as　a　hole　transfer　mediator,　synergistically　affording　spatially　separated　charge　transfer　channels　and　expediting　the　charge　separation/transfer　efficiency.　Benefiting　from　these　merits,　the　self-assembled　M/TMC　heterostructures　exhibited　conspicuously　boosted　photoactivities　in　the　visible　light-driven　selective　organic　transformation　toward　the　anaerobic　reduction　of　aromatic　nitro　compounds　to　amino　derivatives,　which　are　superior　to　pristine　TMCs　and　M/TMCs　without　ligand　encapsulation.　More　significantly,　the　self-assembly　strategy　and　charge　modulation　concept　are　universal　for　diverse　metal　NCs　and　TMCs.　Thus,　our　study　provides　a　general　and　effective　protocol　to　construct　a　host　of　metal/TMC　heterostructures　and　stimulates　new　inspiration　for　modulating　tunable　charge　separation/migration　for　substantial　solar　energy　conversion.　This　journal　is　©　The　Royal　Society　of　Chemistry.