Direct observation of dynamic surface reconstruction and active phases on honeycomb Ni3N−Co3N/CC for oxygen evolution reaction

在析氧反應中, 直接動態觀測 Ni3N−Co3N/CC 表面重構和活性物質

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

1 Scopus Citations
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Author(s)

  • Ping Qin
  • Hao Song
  • Zhifeng Huang
  • Yue Xu

Related Research Unit(s)

Detail(s)

Original languageEnglish
Pages (from-to)2445–2452
Journal / PublicationScience China Materials
Volume65
Issue number9
Online published25 Apr 2022
Publication statusPublished - Sep 2022

Abstract

Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are the key processes in water splitting. Compared with the two-electron process in HER, the four-electron process of OER is slow because of the more complex series of reactions. Therefore, a good understanding of the direct O2 evolution mechanism (DOEM) in OER is crucial to design high-efficiency catalysts to overcome the limitations imposed by the conventional adsorption evolution mechanism. In this work, honeycomb Ni3N−Co3N was prepared on carbon cloth (Ni3N−Co3N/CC) to investigate the DOEM. Density functional theory and in situ Raman scattering spectroscopy demonstrated that the OER process on Ni3N−Co3N/CC proceeded via the DOEM pathway, in which Ni3N and Co3N share the roles of dragging OH, splitting off H−O bonds, and adsorbing other OH, leading to significantly reduced Gibbs’s energy barriers of ΔG*OH to ΔGO*. and ΔGO* to AGO*OH. Moreover, the vertical honeycomb structure and conductive CC substrate contributed to the structural stability, conductivity, and quick O2 release capability. The Ni3N−Co3N/CC required low overpotentials of 320 and 495 mV to reach a current density of 10 and 100 mA cm−2, respectively. Moreover, the Ni3N−Co3N/CC delivered excellent stability with >90% retention of the initial current density over an 80-h-long test.
電解水反應包括析氫和析氧反應. 相對於 2 電子轉移的析氫反應, 4 電子轉移的析氧反應比較緩慢. 因此, 理解析氧反應機制有助於設計高效電催化劑. 其中析氧反應機制可以分為傳統吸附機制和直接氧析出機制. 在本文中, 我們將蜂窩狀 Ni3N−Co3N 生長在碳布上來調研其直接氧析出機制. 密度泛函理論和原位拉曼證明了 Ni3N−Co3N 在反應過程中是直接氧析出機制, 其中 Ni3N 和 Co3N 共同拉拽OH、劈裂 H−O 和吸附另外的 OH 基團, 從而降低了反應活化能. 不僅如此, 蜂窩狀結構和導電基體有助於結構穩定和提高氧氣釋放速率. 因此, Ni3N−Co3N/CC 在 10 和 100 mA cm−2 電流密度下提供了 320 和 495 mV 的小過電勢. 同時, 它也擁有更好的長期穩定性.

Research Area(s)

  • direct O2 evolution mechanism, Ni3N−Co3N/CC, oxygen evolution reaction, surface/interface

Citation Format(s)

Direct observation of dynamic surface reconstruction and active phases on honeycomb Ni3N−Co3N/CC for oxygen evolution reaction. / Qin, Ping; Song, Hao; Ruan, Qingdong; Huang, Zhifeng; Xu, Yue; Huang, Chao.

In: Science China Materials, Vol. 65, No. 9, 09.2022, p. 2445–2452.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review