Hybrid　systems　built　by　coupling　CdS　with　a　series　of　Ru　carbonyl　complexes　([Ru(bpy)(2)(CO)(2)](PF6)(2)　(RC-1),　[Ru(phen)(2)(CO)(2)](PF6)(2)　(RC-2),　[Ru(bPY)(CO)(2)Cl-2]　(RC-3),　[Ru(Me(2)bpy)(CO)(2)Cl-2]　(RC-4),　and　[Ru(phen)(CO)(2)Cl-2]　(RC-5))　showed　activity　for　the　hydrogenation　of　carbonyl　compounds　under　visible-light　irradiations　in　the　presence　of　appropriate　sacrificial　agent.　The　influences　of　the　irradiations　mode,　sacrificial　agent,　substrates,　and　the　structure　of　the　Ru　complexes　on　the　hydrogenation　performance　of　these　composites　were　investigated.　Results　indicated　that　CdS　act　as　the　photosensitizer,　while　the　Ru　carbonyl　complexes　as　catalytic　active　component.　This　study　provides　some　guidance　in　the　development　of　feasible　hybrid　photocatalytic　systems　encompassing　visible-light-responsive　semiconductors　and　redox-active　transition　metal　complexes,　which　are　expected　to　find　great　potentials　in　the　photocatalytic　organic　transformations.　It　is　believed　that　such　photocatalytic　systems　can　be　built　in　a　more　controllable　way　based　on　our　understanding　on　the　structure-activity　relationship　of　the　molecular　electro-catalyst.　(C)　2013　Elsevier　Inc.　All　rights　reserved.