Inspired　by　efficient　perovskite　solar　cells,　we　developed　a　three-component　hybrid　perovskite-based　solar　photocatalyst　cell,　NiOx/FAPbBr3/TiO2,　for　C(sp3)-H　bond　activation　with　high　selectivity　(∼90%)　and　high　conversion　rates　(3800　μmol　g-1　h-1)　under　ambient　conditions.　Time-resolved　spectroscopy　on　our　photocatalytic　cell　reveals　efficient　exciton　dissociation　and　charge　separation,　where　TiO2　and　NiOx　serve　as　the　electron-　and　hole-transporting　layers,　respectively.　The　photogenerated　charge　carriers　injected　into　TiO2　and　NiOx　drive　the　challenging　C-H　activation　reaction　via　the　synergetic　effects　of　their　band　alignment　relative　to　FAPbBr3.　The　reaction　pathway　is　investigated　by　controlling　the　free-radical　formation,　and　we　find　that　C-H　activation　is　mainly　triggered　by　hole　oxidation.　Besides　aromatic　alkanes,　also　the　C(sp3)-H　bond　in　cycloalkanes　can　be　oxidized　selectively.　This　work　demonstrates　a　generic　strategy　for　engineering　high-performance　photocatalysts　based　on　the　perovskite　solar　cell　concept.　©　2018　American　Chemical　Society.