Partially hydroxylated ultrathin iridium nanosheets as efficient electrocatalysts for water splitting

Zifang Cheng, Bolong Huang, Yecan Pi, Leigang Li, Qi Shao, Xiaoqing Huang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

10 Citations (Scopus)

Abstract

Ultrathin two-dimensional (2D) materials have attracted considerable attention for their unique physicochemical properties and promising applications; however, preparation of freestanding ultrathin 2D noble metal remains a significant challenge. Here, for the first time, we report use of a wet-chemical method to synthesize partially hydroxylated ultrathin Ir nanosheets (Ir-NSs) of only five to six atomic layers' thickness. Detailed analysis indicates that the growth confinement effect of carbon monoxide and the partially hydroxylated surface play a critical role in formation of the ultrathin structure. The ultrathin Ir-NSs exhibit excellent performance for both the hydrogen evolution reaction and oxygen evolution reaction in a wide pH range, outperforming the state-of-the-art Pt/C and IrO2, respectively. Density-functional theory calculations reveal that the partial hydroxylation not only enhances the surface electron transfer between Ir-sites and intermediate O-species, but also guarantees efficient initial activation of bond cleavage of H-O-H for first-step H2O splitting.This, ultimately, breaks through barriers to full water splitting, with efficient electron transfer essentially maintained.

Original languageEnglish
Pages (from-to)1340-1348
Number of pages9
JournalNational Science Review
Volume7
Issue number8
DOIs
Publication statusPublished - 1 Aug 2020

Keywords

  • 2D material
  • Hydroxylation
  • Iridium
  • Nanosheet
  • Overall water splitting

ASJC Scopus subject areas

  • General

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