Gold　(Au)　clusters　are　arranged　accurately　at　the　interface　of　semiconductor　photocatalyst　(Zn0.5Cd0.5S)　and　conductor　co-catalyst　(Mo2C),　achieving　(Mo2C/Au)@Zn0.5Cd0.5S　model　configuration,　where　numerous　Au-mediated　link　points　can　serve　as　multifunctional　mediators　for　boosting　photocatalytic　H2　production.　Specifically,　they　could　not　only　enlarge　the　work　function　of　co-catalyst　component　to　provide　a　greater　driving　force　for　accelerating　carriers＇　intercomponent　separation,　but　also　act　as　the　electronic　tunnels　and　thus　switch　contact　mode　from　Schottky　contact　to　analogous　ohmic　contact　to　eliminate　the　interfacial　electrons　transfer　resistance　originated　from　the　Schottky　barrier　in　semiconductor/conductor　interface.　Besides,　they　could　also　regulate　the　electronic　configuration　of　co-catalyst　to　lower　the　H-2　evolution　overpotential　of　the　photocatalyst　system.　The　synergy　of　Zn0.5Cd0.5S,　Mo2C　and　interfacial　Au　endows　(Mo2C/Au)@Zn0.5Cd0.5S　a　soaring　photocatalytic　H-2　evolution　performance.　The　corresponding　rate　of　H-2　production　reaches　up　to　21.819　mmol　h(-1)　g(-1)　under　visible　light　irradiation,　which　is　about　28.9　times　higher　than　that　of　Zn0.5Cd0.5S,　even　2.7　times　as　high　as　that　of　Mo2C@Zn0.5Cd0.5S.　The　designed　model　structure　takes　full　advantage　of　the　synergy　between　components　and　interfaces　via　modulating　interfacial　structure　at　the　atomic　scale,　which　provides　a　new　idea　for　systematically　optimizing　semiconductors,　co-catalysts　and　interfaces　toward　efficient　solar　to　energy　conversion.