The rational design of double active sites system is vital for constructing high-efficiency iron sulfides electrocatalysts towards hydrogen evolution reaction(HER)in alkaline media.However,it remains a challenge to controllably create the high-density interface of double sites for optimal synergistic effect.Herein,we reported a simple chemical oxidation-induced surface reconfiguration strategy to obtain the interface-rich Fe3O4-FeS nanoarray supported on iron foam(Fe3O4-FeS/IF)using FeS nanosheets as precursors.The abundant Fe3O4-FeS interfaces could improve the dispersion of active sites and facilitate the electron transfer,leading to enhanced hydrogen evolution efficiency.And meanwhile,by altering the oxidation temperature,the content of S and O could be effectively controlled,further achieving the ratio optimization of Fe3O4 to FeS.Synchrotron-based X-ray absorption near-edge structure,X-ray photoelec-tron spectroscopy and ultraviolet photoemission spectroscopy consistently confirm the changes of elec-tronic structure and d-band center of Fe3O4-FeS after chemical oxidation.Consequently,Fe3O4-FeS/IF exhibits excellent alkaline HER activity with a low overpotential of 120.8 mV to reach 20 mA cm-2,and remains stable ranging from 10,20 to 50 mA cm-2 for each 20 h,respectively.Therefore,the facile and controllable chemical oxidation may be an effective strategy for designing high-density interfaces of transition metal-based sulfides towards alkaline HER.

State Key Laboratory of Heavy Oil Processing,College of Chemical Engineering,China University of Petroleum(East China),Qingdao 266580,Shandong,China;Department of Chemistry,Marquette University,Milwaukee,WI 53201,United States;X-ray Science Division,Argonne National Laboratory,Argonne,IL 60349,United States

[1]Min Yang;Wen-Hui Hu;Meng-Xuan Li;Yu-Ning Cao;Bin Dong;Yu Ma;Hui-Ying Zhao;Feng-Ge Wang;Jier Huang;Yong-Ming Chai-.Controlled high-density interface engineering of Fe3O4-FeS nanoarray for efficient hydrogen evolution)[J].能源化学,2022(05):96-103

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