Recent　years　have　witnessed　a　cornucopia　of　synthetic　methods　for　fabricating　carbon-metal　nanocomposites.　Nonetheless,　achieving　a　cooperative　synergy　of　zero-dimensional　carbon　nanomaterials　and　metal　nanocrystals　is　still　uncommon.　To　this　end,　we　performed　a　controllable　structural　design　comprising　customizable　alternating　layers　of　active　and　functional　zero-dimensional　nanomaterials,　which　were　intimately　assembled　together.　This　unique　highly-ordered　multilayer　configuration　was　afforded　by　a　judicious　layer-by-layer　(LbL)　assembly　strategy,　enabling　the　rational　and　tunable　construction　of　a　series　of　well-defined　metal/graphene　quantum　dots　(M/GQDs)n　(M　=　Au,　Ag,　Pt)　multilayers.　This　strategy　allows　the　direct　assembly　of　customized　units　of　positively-charged　graphene　quantum　dots　(GQDs)　and　negatively-charged　metal　nanocrystals　(NCs),　which　were　integrated　in　an　alternating　stacked　fashion　under　a　pronounced　electrostatic　attractive　interaction.　Moreover,　these　multilayer　thin　films　demonstrate　remarkably　efficient　and　versatile　catalytic　performance　toward　the　selective　organic　transformation　of　aromatic　nitro　compounds,　electrocatalytic　methanol　oxidation　and　photoelectrochemical　water　splitting　under　simulated　solar　light　irradiation　under　ambient　conditions,　attributed　to　the　cooperative　synergy　of　the　metal　NC　and　GQD　building　blocks.　More　significantly,　the　catalytic　performances　of　the　(M/GQDs)n　(M　=　Au,　Ag,　Pt)　multilayer　thin　films　are　tunable　via　the　assembly　cycle　and　sequence,　as　well　as　by　selecting　different　metal　NC　types.　This　work　highlights　the　significance　of　the　customizable　design　of　GQDs-metal-based　systems　for　various　advanced　chemical-to-energy　conversion　applications.　©　2018　The　Royal　Society　of　Chemistry.