A rational regula-tion of the solar water splitting reaction pathway by adjusting the surface composition and phase structure of catalysts is a substantial approach to amelio-rate the sluggish reaction kinetics and improve the energy conver-sion efficiency.In this study,we demonstrate a nanocrystalline iron pyrophosphate(Fe4(P2O7)3,FePy)-regulated hybrid overlayer with amorphous iron phosphate(FePO4,FePi)on the surface of metal oxide nanostructure with boosted photoelectrochemical(PEC)water oxidation.By manipulating the facile electrochemical surface treatment followed by the phosphating process,nanocrystalline FePy is localized in the FePi amorphous overlayer to form a heterogeneous hybrid structure.The FePy-regulated hybrid overlayer(FePy@FePi)results in significantly enhanced PEC performance with long-term durability.Compared with the homogeneous FePi amorphous overlayer,FePy@FePi can improve the charge transfer efficiency more significantly,from 60％of FePi to 79％of FePy@FePi.Our density-functional theory calculations reveal that the coexistence of FePi and FePy phases on the surface of metal oxide results in much better oxygen evolution reaction kinetics,where the FePi was found to have a typical down-hill reaction for the conversion from OH*to O2,while FePy has a low free energy for the formation of OH*.

Chengkai Xia;Yuankai Li;Minyeong Je;Jaekyum Kim;Sung Min Cho;Chang Hyuck Choi;Heechae Choi;Tae-Hoon Kim;Jung Kyu Kim

School of Chemical Engineering,Sungkyunkwan University(SKKU),2066 Seobu-ro,Jangan-gu,Suwon 16419,Republic of Korea;Theoretical Materials and Chemistry Group,Institute of Inorganic Chemistry,University of Cologne,Greinstr.6,50939 Cologne,Germany;Department of Chemistry,Pohang University of Science and Technology(POSTECH),Pohang 37673,Republic of Korea;Department of Materials Science and Engineering,Engineering Research Center,Chonnam National University,Gwangju 61186,Republic of Korea

纳微快报（英文）

[1]Chengkai Xia;Yuankai Li;Minyeong Je;Jaekyum Kim;Sung Min Cho;Chang Hyuck Choi;Heechae Choi;Tae-Hoon Kim;Jung Kyu Kim-.Nanocrystalline Iron Pyrophosphate-Regulated Amorphous Phosphate Overlayer for Enhancing Solar Water Oxidation)[J].纳微快报（英文）,2022(12):387-400

Pyrophosphate,Overlayer,FePy,FePi

Nanocrystalline,Iron,Regulated,Amorphous,Phosphate,Enhancing,Solar,Water,Oxidation,rational,solar,water,splitting,reaction,pathway,by,adjusting,surface,composition,catalysts,substantial,approach,amelio,sluggish,kinetics,improve,energy,efficiency,In,this,study,demonstrate,nanocrystalline,iron,pyrophosphate,Fe4,P2O7,regulated,hybrid,overlayer,amorphous,FePO4,metal,oxide,nanostructure,boosted,photoelectrochemical,PEC,oxidation,By,manipulating,facile,treatment,followed,phosphating,process,localized,heterogeneous,results,significantly,enhanced,performance,long,term,durability,Compared,homogeneous,charge,transfer,more,from,Our,density,functional,theory,calculations,reveal,that,coexistence,phases,much,better,oxygen,evolution,where,was,found,have,typical,down,hill,conversion,O2,while,free,formation

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