Constructing hierarchical nanosheet-on-microwire FeCo LDH@Co3O4 arrays for high-rate water oxidation  

作　　者：Tang Tang Zhe Jiang Jun Deng Shuai Niu Ze-Cheng Yao Wen-Jie Jiang Lin-Juan Zhang Jin-Song Hu 

机构地区：[1]Beijing National Laboratory for Molecular Sciences(BNLMS),CAS Key Laboratory of Molecular Nanostructure and Nanotechnology,Institute of Chemistry,Chinese Academy of Sciences,Beijing,100190,China [2]University of the Chinese Academy of Sciences,Beijing,100049,China [3]Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing,100190,China [4]Shanghai Synchrotron Radiation Facility,Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai,201800,China [5]Dalian National Laboratory for Clean Energy,Dalian,116023,China

出　　处：《Nano Research》2022年第12期10021-10028,共8页纳米研究（英文版）

基　　金：the financial support from the National Natural Science Foundation of China(Nos.22025208,22075300,and 21902162);the China National Postdoctoral Program for Innovative Talents(No.BX2021319);the DNL Cooperation Fund,CAS(No.DNL202008);the Chinese Academy of Sciences.

摘　　要：Alkaline electrochemical water oxidation powered by renewable energies is a promising and environmentally friendly way to produce hydrogen.The industrial water electrolyzers are commonly operated at a high current density,calling for abundant and durable active sites to participate in.The rational design of hierarchically structured electrocatalysts is thus essential to industrial water electrolyzers.Herein,we develop a Fe3+induced nanosizing strategy for fabricating such a hierarchical FeCo LDH@Co3O4(LDH:layered double hydroxide)nanostructure array for high-rate water oxidation.Density functional theory(DFT)simulations indicate that the introduction of Fe3+with a small ion radius and high electrical repulsion in the LDH layer distorted the LDH layer,resulting in a reduced nanosheet size and enabling the formation of a hierarchical structure.Such structure cannot be achieved without the participation of Fe3+cations.Benefiting from the significantly enhanced electrochemical surface areas and charge/mass transport due to the hierarchical structure together with the boosted intrinsic activity by electronic modulation of Fe3+,such FeCo LDH@Co3O4 electrode can deliver an industrial-level current density of 1,000 mA·cm-2 at a small overpotential of 392 mV for water oxidation.When assembled in a water electrolyzer,it delivers a current density of 100 mA·cm-2 at a low operation voltage of 1.61 V.Powered by solar light,the electrolyzer demonstrates high solar-to-hydrogen efficiency of 18.15%with stable and reproducible photoresponse.These results provide new insights for constructing hierarchical nanostructures for advanced water oxidation and other diverse applications.

关 键 词：ELECTROCATALYSTS oxygen evolution reaction water splitting hierarchical structures layered double hydroxides 

分 类 号：TB383[一般工业技术—材料科学与工程]