We　report　a　simple　and　general　approach　to　improve　the　transfer　efficiency　of　photogenerated　charge　carriers　across　the　interface　between　graphene　(GR)　and　semiconductor　CdS　by　introducing　a　small　amount　of　metal　ions　(Ca2+,　Cr3+,　Mn2+,　Fe2+,　Co2+,　Ni　2+,　Cu2+,　and　Zn2+)　as　＂mediator＂　into　their　interfacial　layer　matrix,　while　the　intimate　interfacial　contact　between　GR　and　CdS　is　maintained.　This　simple　strategy　can　not　only　significantly　improve　the　visible-light-driven　photoactivity　of　GR-CdS　semiconductor　composites　for　targeting　selective　photoredox　reaction,　including　aerobic　oxidation　of　alcohol　and　anaerobic　reduction　of　nitro　compound,　but　also　drive　a　balance　between　the　positive　effect　of　GR　on　retarding　the　recombination　of　electron-hole　pairs　photogenerated　from　semiconductor　and　the　negative　＂shielding　effect＂　of　GR　resulting　from　the　high　weight　addition　of　GR.　Our　current　work　highlights　that　the　significant　issue　on　improving　the　photoactivity　of　GR-semiconductor　composites　via　strengthening　interfacial　contact　is　not　just　a　simple　issue　of　tighter　connection　between　GR　and　the　semiconductor,　but　it　is　also　the　optimization　of　the　atomic　charge　carrier　transfer　pathway　across　the　interface　between　GR　and　the　semiconductor.　©　2013　American　Chemical　Society.