In　photocatalytic　systems,　the　transfer　of　electrons　from　semiconductor　nanostructures　to　the　reduction　cocatalysts　is　the　key　electronic　process,　which　determines　the　effective　separation　of　photogenerated　charge　carriers,　and　is　sensitively　influenced　by　the　band　structures　of　the　contacts.　Due　to　improper　adoption　of　cocatalysts,　interfacial　charge　transfer　is　usually　suffering　from　excessive　energy　dissipation　by　thermionic　emission,　which　kinetically　prevents　this　electronic　process　and　eventually　aggravates　the　recombination　of　photogenerated　charge　carriers.　Unfortunately,　this　issue　has　hardly　been　consciously　considered.　The　formed　potential　barriers,　which　are　mainly　determined　by　the　adoption　of　cocatalyst,　kinetically　predominates　the　interfacial　charge　transfer　as　well　as　the　whole　photocatalytic　reaction.　In　this　work,　inspired　by　theoretical　simulation,　we　adopt　platinum　and　MoS2　that　deposited　on　semiconductor　nanostructures　as　the　models　to　demonstrate　the　energy　dissipation　that　kinetically　influences　the　interfacial　charge　transfer.　Despite　high　catalytic　activity,　the　intolerably　high　energy　dissipation　for　interfacial　charge　transfer　hides　the　superiority　of　platinum,　resulting　in　an　inferior　photocatalytic　performance　to　that　of　MoS2.　Our　work　rationally　unfastens　the　deliberative　consideration　of　intrinsic　activity　and　prompts　the　exploration　of　cocatalysts　for　photocatalyst　designing.　©　2019　American　Chemical　Society.