We　have　developed　a　facile　and　easily　accessible　layer-by-layer　(LBL)　self-assembly　route　to　synthesize　hierarchically　ordered　M/TNTs　(M　=　Au,　Ag,　Pt)　heterostructures.　These　integrated　heterostructures　show　remarkably　enhanced　photoactivity　and　outstanding　photostability;　photoelectrochemical　exploitations　substantiated　the　contribution　role　of　metal　NPs　acting　as　＇electron　reservoir＇　in　prolonging　the　lifetime　of　photogenerated　electron-hole　charge　carriers.　In　addition,　these　well-defined　self-assembled　hybrid　systems　can　also　be　used　as　a　promising　catalyst　for　recycled　selective　catalytic　reduction　of　4-nitrophenol　toward　4-aminophenol.　The　integration　of　high　photoactivity　and　efficient　catalytic　reduction　properties　of　the　heterostructures　lies　crucially　on　the　LBL　self-assembly-induced　monodispersivity　of　metal　NPs　on　the　framework　of　TNTs,　and,　particularly,　the　intimate　interfacial　contact　between　metal　NPs　and　TNTs　substrate　arising　from　the　pronounced　electrostatic　attractive　interaction　afforded　by　polyelectrolytes　multilayering.　Our　results　show　that　the　design　and　utilization　of　highly　ordered　metal/1-D　semiconductor　hybrid　nanostructures　based　on　the　facile　LBL　self-assembly　strategy　can　find　diverse　catalytic　applications.　©　2012　American　Chemical　Society.