A　variety　of　ternary　nanoheterostructures　composed　of　Pt　nanoparticles　(NPs),　SnOx　species,　and　anatase　TiO2　are　designed　elaborately　to　explore　the　effect　of　interfacial　electron　transfer　on　photocatalytic　H-2　evolution　from　a　biofuel-water　solution.　Among　numerous　factors　controlling　the　H-2　evolution,　the　significance　of　Pt　sites　for　the　H-2　evolution　is　highlighted　by　tuning　the　loading　procedure　of　Pt　NPs　and　SnOx　species　over　TiO2.　A　synergistic　enhancement　of　H-2　evolution　can　be　achieved　over　the　Pt/SnOx/TiO2　heterostructures　formed　by　anchoring　Pt　NPs　at　atomically-isolated　Sn-oxo　sites,　whereas　the　Pt/TiO2/SnOx　counterparts　prepared　by　grafting　single-site　Sn-oxo　species　on　Pt/TiO2　show　a　marked　decrease　in　the　rate　of　H-2　evolution.　The　characterization　results　clearly　reveal　that　the　synergy　of　Pt　NPs　and　SnOx　species　originates　from　the　vectorial　electron　transfer　of　TiO2　-＞　SnOx　-＞　Pt　occurring　on　the　former,　while　the　latter　results　from　the　competitive　electron　transfer　from　TiO2　to　SnOx　and　to　Pt　NPs.