Atomically　precise　metal　nanoclusters　(NCs)　have　recently　emerged　as　a　promising　sector　of　metal　nanomaterials　in　terms　of　peculiar　atomic　stacking　fashion,　quantum　confinement　effect,　and　enriched　catalytically　active　sites,　which　are　wholly　distinct　from　conventional　metal　nanocrystals　(NYs)　in　all　respects.　However,　atomically　precise　metal　NCs　inevitably　suffer　from　intrinsic　poor　instability　either　under　light　irradiation　or　thermal　treatment　owing　to　the　ultrahigh　surface　energy,　thereby　resulting　in　substantial　loss　of　photosensitization　efficiency　and　retarding　their　emerging　utilization　in　photoredox　catalysis.　Here,　we　first　conceptually　reveal　the　charge　transfer　characteristic　difference　between　atomically　precise　metal　NCs　and　metal　NYs　attained　by　self-transformation　in　boosting　interfacial　charge　migration　and　separation.　The　results　signify　that　the　interfacial　charge　transfer　impetus　of　atomically　precise　metal　NCs　as　a　photosensitizer　versus　metal　NYs　as　a　Schottky-type　electron-withdrawing　mediator　is　closely　associated　with　the　loading　amount　on　the　semiconductor　substrate.　The　photosensitization　effect　of　atomically　precise　metal　NCs　is　superior　to　the　electron　trapping　capability　of　metal　NYs　when　the　loading　amount　of　the　metal　ingredient　is　relatively　high　and　vice　versa.　Our　work　would　significantly　bridge　the　gap　between　atomically　precise　metal　NCs　and　metal　NYs　in　fine　tuning　of　the　charge　transfer　pathway　in　photocatalysis　toward　solar　energy　conversion.　©　2022　American　Chemical　Society.