Interfacial Charge Transfer Bridge Prolongs Carrier Recombination Lifetimes of CoFe Metal‐Thiolate Framework/Hematite Photoanode for Water Oxidation
Tao Yang, Zongwei Chen, Xin‐Zheng Yue, Qingchao Liu, Shasha Yi, Yongfa Zhu
Abstract
Abstract Constructing heterostructural photoanodes is attractive for elevating the photoelectrochemical (PEC) performance, however, it is a long‐standing challenge to achieve highly efficient interfacial charge transfer. Herein, a CoFe metal‐thiolate framework (CoFe MTF)/Fe 2 O 3 photoanode connected by an interfacial Fe─O─N/S bond is designed to modulate the behavior of charge carriers and improve water oxidation performance. It is disclosed that this interfacial bond functions as a direct charge transfer bridge between shallow trap states of Fe 2 O 3 and CoFe MTF, leading to prolonged carrier recombination lifetimes (85 ns for CoFe MTF/Fe 2 O 3 compared to 37 ns for Fe 2 O 3 ) and enhanced charge transfer efficiency. Alternatively, a robust interfacial electric field is established in the CoFe MTF/Fe 2 O 3 p–n heterojunction, facilitating efficient charge transfer. As expected, the CoFe MTF/Fe 2 O 3 photoanode exhibits significant enhancement in water oxidation, resulting in a three‐fold increase in photocurrent density compared to pristine Fe 2 O 3 . This study highlights the significance of designing interfacially bonded heterostructural photoelectrodes to regulate the transfer characters of charge carriers.