@article{1d38522cf15c451480f4fc4cef5021fa,
title = "Unraveling Ni-Fe 2D nanostructure with enhanced oxygen evolution via in situ and operando spectroscopies",
abstract = "Ni-Fe-based materials are well known as one of the most active electrocatalysts for the oxygen evolution reaction (OER) in alkaline environments. In this study, we propose a facile and scaling up synthesis route using a surfactant for Ni-Fe 2D nanostructured electrocatalysts. Furthermore, we uncovered the hidden phase transformation mechanism of 2D Ni-Fe layered double hydroxide (LDH) electrocatalysts by combining various in situ and operando analyses. The Ni-Fe LDH underwent a chemically induced phase transformation in an alkaline environment without applied potential. The resulting phase transformation product persisted throughout the entire OER mechanism cycle, such that it played a dominant role in the process. The presence of high-valent Ni and Fe was observed on the surface; hence, the OER selectivity and catalytic turnover frequency were enhanced in the low-overpotential domain. Our study not only uncovers the fundamentals of Ni-Fe LDH but also expands the potential for practical alkaline water splitting.",
keywords = "AEM, anion exchange membrane electrolyzer, in situ and operando analyses, Ni-Fe 2D nanostructure, OER, online ICP-MS, oxygen evolution reaction mechanism, SDG7: Affordable and clean energy",
author = "Ko, {Young Jin} and Han, {Man Ho} and Haesol Kim and Kim, {Jun Yong} and Lee, {Woong Hee} and Jaewook Kim and Kwak, {Joon Young} and Kim, {Chang Hee} and Park, {Tae Eon} and Yu, {Seung Ho} and Lee, {Wook Seong} and Choi, {Chang Hyuck} and Peter Strasser and Oh, {Hyung Suk}",
note = "Funding Information: This work was supported by institutional program grants from the Korea Institute of Science and Technology and the “Carbon to X Project” (project no. 2020M3H7A1098229) of the National Research Foundation (NRF), funded by the Ministry of Science and ICT (Republic of Korea). This work was also supported by National Research Council of Science & Technology (NST) grants from the Korean government (MSIP) (nos. CAP-17-04-KRISS and CAP21011-100) and NRF grants funded by the Korean government (MSIT) (NRF-2020R1A2C4002233 and NRF-2021R1A2C2093467). C.H.C. acknowledges financial support from an NRF grant funded by the Ministry of Science and ICT (NRF-2020R1A2C400223311). Y.-J.K. M.H.H. and H.K. contributed equally to this work. H.-S.O. and P.S. conceived the idea and supervised the work. C.H.C. provided an idea for the in situ and operando analysis. Y.-J.K. designed the experiments, analyzed the data, and wrote the manuscript. M.H.H. conducted the electrochemical experiments and wrote the paper. H.K. performed DEMS and online ICP-MS analysis and interpreted the data in the manuscript regarding OER performance. J.-Y.K. provided an idea for the synthesis of Ni-Fe catalysts. W.H.L. measured the prepared electrocatalysts in single-cell-device conditions. B.K.M. provided an idea for electrochemical analysis. S.-H.Y. and J.Y.K. provided an idea for SERS and other surface analysis. W.-S.L. and J.K. interpreted the data in the first part of the paper regarding the synthesis mechanism. All authors reviewed the manuscript and agreed on its content. The authors declare no competing interests. Funding Information: This work was supported by institutional program grants from the Korea Institute of Science and Technology and the “Carbon to X Project” (project no. 2020M3H7A1098229 ) of the National Research Foundation (NRF), funded by the Ministry of Science and ICT (Republic of Korea). This work was also supported by National Research Council of Science & Technology (NST) grants from the Korean government ( MSIP ) (nos. CAP-17-04-KRISS and CAP21011-100 ) and NRF grants funded by the Korean government ( MSIT ) ( NRF-2020R1A2C4002233 and NRF-2021R1A2C2093467 ). C.H.C. acknowledges financial support from an NRF grant funded by the Ministry of Science and ICT ( NRF-2020R1A2C400223311 ). Publisher Copyright: {\textcopyright} 2022 The Author(s)",
year = "2022",
month = sep,
day = "15",
doi = "10.1016/j.checat.2022.07.016",
language = "English",
volume = "2",
pages = "2312--2327",
journal = "Chem Catalysis",
issn = "2667-1107",
publisher = "Cell Press",
number = "9",
}
