Unraveling Ni-Fe 2D nanostructure with enhanced oxygen evolution via in situ and operando spectroscopies

Young Jin Ko, Man Ho Han, Haesol Kim, Jun Yong Kim, Woong Hee Lee, Jaewook Kim, Joon Young Kwak, Chang Hee Kim, Tae Eon Park, Seung Ho Yu, Wook Seong Lee, Chang Hyuck Choi, Peter Strasser, Hyung Suk Oh

    Research output: Contribution to journalArticlepeer-review

    35 Citations (Scopus)

    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.

    Original languageEnglish
    Pages (from-to)2312-2327
    Number of pages16
    JournalChem Catalysis
    Volume2
    Issue number9
    DOIs
    Publication statusPublished - 2022 Sept 15

    Bibliographical note

    Publisher Copyright:
    © 2022 The Author(s)

    Keywords

    • AEM
    • Ni-Fe 2D nanostructure
    • OER
    • SDG7: Affordable and clean energy
    • anion exchange membrane electrolyzer
    • in situ and operando analyses
    • online ICP-MS
    • oxygen evolution reaction mechanism

    ASJC Scopus subject areas

    • Chemistry (miscellaneous)
    • Physical and Theoretical Chemistry
    • Organic Chemistry

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