Dual mediators promote charge transfer of hematite photoanode for durable photoelectrocatalytic water splitting  

双电荷传输媒介促进赤铁矿光阳极的电荷转移实现高效光电催化水分解

作　　者：Yuanyuan Jiang Yan Zhang Mengmeng Liu Lulu Liu Hong Chen Sheng Ye 蒋元元;张妍;刘梦梦;刘璐璐;陈红;叶盛(安徽农业大学材料与化学学院农业光催化实验室,安徽合肥230036)

机构地区：[1]Agricultural Photocatalysis Laboratory,School of Materials and Chemistry,Anhui Agricultural University,Hefei 230036,Anhui,China

出　　处：《Chinese Journal of Catalysis》2025年第2期75-83,共9页催化学报(英文)

基　　金：国家自然科学基金(22372001);安徽省自然科学基金优青项目(2408085Y008);安徽农业大学高层次人才科研启动基金(rc382108);国家级大学生创新创业训练计划(X202310364209).

摘　　要：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.摘要:氢能作为一种环境友好、无污染的可再生能源备受关注.光电催化(PEC)分解水制氢因其温和的反应条件、较少的逆反应和副反应、氧化反应与还原反应空间隔离实现氢氧产物分离等优点,成为极具发展潜力的产氢途径.当前,许多金属氧化物半导体,如TiO_(2),WO_(3),BiVO_(4)和α-Fe_(2)O_(3)等被广泛用作PEC水分解的光阳极材料。α-Fe_(2)O_(3)半导体具有宽广的吸收光谱以及成本较低等优点,被认为是最有前途的光阳极材料之一。然而,由于α-Fe_(2)O_(3)半导体材料存在严重的电荷复合、低电子导电率和缓慢的水氧化反应动力学等问题,极大地限制了其在光电催化水分解中的实际应用.鉴于光生电荷分离与传输在PEC中的关键作用,调控表界面的电荷转移行为成为解析光电催化水分解过程的核心科学问题.本研究采用α-Fe_(2)O_(3)半导体作为捕光材料,以及可抑制半导体与衬底之间载流子复合的SnO_(x)作为电子传输媒介,可促进半导体与水氧化催化剂之间空穴转移的部分氧化石墨烯(pGO)作为空穴传输媒介,并以钻分子立方烷作为水氧化催化剂,成功组装了一种高性能的Ti掺杂赤铁矿光阳极(Co/pGO/TiFeO/SnO_(x)),该体系在光电催化分解水反应中展现了较好的性能.在1.23VRHE下,Co/pGO/TiFeO/SnO_(x)光阳极的光电流密度达到2.52mAcm^(-2),是本体TiFeO光阳极(1.04mAcm^(-2))的2.4倍,且在100h的光电催化水分解过程中表现出良好的稳定性.原位X射线衍射和原位拉曼光谱进一步证实了Co/pGO/TiFeO/SnO_(x)光阳极结构的稳定.通过瞬态荧光光谱和瞬态吸收光谱表征光诱导载流子的动力学特性,结果表明,Co/pGO/TiFeO/SnO_(x)光阳极的荧光寿命缩短,载流子寿命延长,证实双电荷传输媒介(pGO和SnO_(x))有效促进了电荷分离,减少了电荷复合.强度调制光电流谱(IMPS)结果表明,与TiFeO,Co/TiFeO和Co/pGO/TiFeO光阳极相比,Co/pGO/TiFeO/SnO_(x)表现�

关 键 词：HEMATITE Molecular catalyst Charge transfer mediator Photoelectrocatalytic water splitting 

分 类 号：O643.3[理学—物理化学] O643.36[理学—化学]