PMID- 30019788 OWN - NLM STAT- Publisher LR - 20240227 IS - 1521-4095 (Electronic) IS - 0935-9648 (Linking) DP - 2018 Jul 18 TI - Iron Vacancies Induced Bifunctionality in Ultrathin Feroxyhyte Nanosheets for Overall Water Splitting. PG - e1803144 LID - 10.1002/adma.201803144 [doi] AB - Exploring of new catalyst activation principle holds a key to unlock catalytic powers of cheap and earth-abundant materials for large-scale applications. In this regard, the vacancy defects have been proven to be effective to initiate catalytic active sites and endow high electrocatalytic activities. However, such electrocatalytically active defects reported to date have been mostly formed by anion vacancies. Herein, it is demonstrated for the first time that iron cation vacancies induce superb water splitting bifunctionality in alkaline media. A simple wet-chemistry method is developed to grow ultrathin feroxyhyte (delta-FeOOH) nanosheets with rich Fe vacancies on Ni foam substrate. The theoretical and experimental results confirm that, in contrast to anion vacancies, the formation of rich second neighboring Fe to Fe vacancies in delta-FeOOH nanosheets can create catalytic active centers for both hydrogen and oxygen evolution reactions. The atomic level insight into the new catalyst activation principle based on metal vacancies is adaptable for developing other transition metal electrocatalysts, including Fe-based ones. CI - (c) 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. FAU - Liu, Bin AU - Liu B AD - Center of Super-Diamond and Advanced Films (COSDAF), Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. FAU - Wang, Yun AU - Wang Y AD - Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland, 4222, Australia. FAU - Peng, Hui-Qing AU - Peng HQ AD - Department of Chemistry, Institute for Advanced Study, Institute of Molecular Functional Materials and Division of Biomedical Engineering, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China. FAU - Yang, Ruoou AU - Yang R AD - Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China. FAU - Jiang, Zheng AU - Jiang Z AD - Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China. FAU - Zhou, Xingtai AU - Zhou X AD - Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China. FAU - Lee, Chun-Sing AU - Lee CS AD - Center of Super-Diamond and Advanced Films (COSDAF) & Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. FAU - Zhao, Huijun AU - Zhao H AD - Centre for Clean Environment and Energy, Gold Coast Campus, Griffith University, Queensland, 4222, Australia. FAU - Zhang, Wenjun AU - Zhang W AUID- ORCID: 0000-0002-4497-0688 AD - Center of Super-Diamond and Advanced Films (COSDAF), Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China. LA - eng PT - Journal Article DEP - 20180718 PL - Germany TA - Adv Mater JT - Advanced materials (Deerfield Beach, Fla.) JID - 9885358 OTO - NOTNLM OT - atomic level insight OT - catalyst activation principle OT - iron cation vacancies OT - ultrathin feroxyhyte nanosheets OT - water splitting bifunctionality EDAT- 2018/07/19 06:00 MHDA- 2018/07/19 06:00 CRDT- 2018/07/19 06:00 PHST- 2018/05/16 00:00 [received] PHST- 2018/06/13 00:00 [revised] PHST- 2018/07/19 06:00 [entrez] PHST- 2018/07/19 06:00 [pubmed] PHST- 2018/07/19 06:00 [medline] AID - 10.1002/adma.201803144 [doi] PST - aheadofprint SO - Adv Mater. 2018 Jul 18:e1803144. doi: 10.1002/adma.201803144.