Assessing nickel oxide electrocatalysts incorporating diamines and having improved oxygen evolution activity using operando UV/visible and X-ray absorption spectroscopy

Takafumi Miura, Shun Tsunekawa, Sho Onishi, Toshiaki Ina, Kehsuan Wang, Genta Watanabe, Chechia Hu, Hiroshi Kondoh, Takeshi Kawai, Masaaki Yoshida

研究成果: Article査読

4 被引用数 (Scopus)

抄録

The electrolysis of water using renewable energy is a promising approach to developing a sustainable hydrogen-based economy. To improve the efficiency of this process, it will be necessary to develop highly active electrocatalysts that promote the oxygen evolution reaction (OER). In the present study, the OER activity of a nickel oxide electrocatalyst was dramatically improved following the addition of a diamine to the electrolyte solution during electrodeposition. Operando UV/vis absorption spectroscopy was used to assess a number of nickel catalysts containing various diamines and other organic compounds. The data indicate that Ni(ii) complexes were formed with the diamines during electrodeposition. Consequently, the catalytic activity of these materials was enhanced based on increased concentrations of active reaction sites for the OER process. Ni K-edge X-ray absorption spectra showed that these catalysts were composed of γ-NiOOH with a Ni3.6+ valence state. The coordination of the diamine molecules to the γ-NiOOH produced structural distortion that contributed to improved OER activity. This structural distortion is likely the most important factor in enhancing the OER activity of inorganic-organic composite catalysts.

本文言語English
ページ(範囲)23280-23287
ページ数8
ジャーナルPhysical Chemistry Chemical Physics
23
40
DOI
出版ステータスPublished - 2021 10月 28

ASJC Scopus subject areas

  • 物理学および天文学(全般)
  • 物理化学および理論化学

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