Regulating the interfacial charge transfer is pivotal for elucidating the kinetics of engineering the interface between the light-harvesting semiconductor and the substrate/catalyst for photoelectrocatalytic water spl...Regulating the interfacial charge transfer is pivotal for elucidating the kinetics of engineering the interface between the light-harvesting semiconductor and the substrate/catalyst for photoelectrocatalytic water splitting.In this study,we constructed a superior Ti-doped hematite photoanode(TiFeO)by employing SnOx as an electron transfer mediator,partially oxidized graphene(pGO)as a hole transfer mediator,and molecular Co cubane as a water oxidation catalyst.The Co/pGO/TiFeO/SnO_(x)integrated system achieves a photocurrent density of 2.52 mA cm^(-2) at 1.23 VRHE,which is 2.4 times higher than bare photoanode(1.04 mA cm^(-2)),with operational stability up to 100 h.Kinetic measurements indicate that pGO can promote charge transfer from TiFeO to the Co cubane catalyst.In contrast,SnOx reduces charge recombination at the interface between TiFeO and the fluorinated tin oxide substrate.In-situ infrared spectroscopy shows the formation of an O–O bonded intermediate during water oxidation.This study highlights the crucial role of incorporating dual charge-transfer mediators into photoelectrodes for efficient solar energy conversion.展开更多
文摘Regulating the interfacial charge transfer is pivotal for elucidating the kinetics of engineering the interface between the light-harvesting semiconductor and the substrate/catalyst for photoelectrocatalytic water splitting.In this study,we constructed a superior Ti-doped hematite photoanode(TiFeO)by employing SnOx as an electron transfer mediator,partially oxidized graphene(pGO)as a hole transfer mediator,and molecular Co cubane as a water oxidation catalyst.The Co/pGO/TiFeO/SnO_(x)integrated system achieves a photocurrent density of 2.52 mA cm^(-2) at 1.23 VRHE,which is 2.4 times higher than bare photoanode(1.04 mA cm^(-2)),with operational stability up to 100 h.Kinetic measurements indicate that pGO can promote charge transfer from TiFeO to the Co cubane catalyst.In contrast,SnOx reduces charge recombination at the interface between TiFeO and the fluorinated tin oxide substrate.In-situ infrared spectroscopy shows the formation of an O–O bonded intermediate during water oxidation.This study highlights the crucial role of incorporating dual charge-transfer mediators into photoelectrodes for efficient solar energy conversion.
