Surface Rh-Boosted Photoelectrochemical Water Oxidation of α-Fe2O3 by Reduced Overpotential in the Rate-Determining Step

Young Min Kim, Yerin Hong, Kahyun Hur, Min Seok Kim, Yun Mo Sung

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)

Abstract

The photoelectrochemical behavior of Rh cluster-deposited hematite (α-Fe2O3) photoanodes (α-Fe2O3@Rh) was investigated. The interactions between Rh clusters and α-Fe2O3 nanorods were elucidated both experimentally and computationally. A facile UV-assisted solution casting deposition method allowed the deposition of 2 nm Rh clusters on α-Fe2O3. The deposited Rh clusters effectively enhanced the photoelectrochemical performance of the α-Fe2O3 photoanode, and electrochemical impedance spectroscopy (EIS) and Mott-Schottky analysis were applied to understand the working mechanism for the α-Fe2O3@Rh photoanodes. The results revealed a distinctive carrier transport mechanism for α-Fe2O3@Rh and increased carrier density, while the absorbance spectra remained unchanged. Furthermore, density functional theory (DFT) calculations of the oxygen evolution reaction (OER) mechanism corresponded well with the experimental results, indicating a reduced overpotential of the rate-determining step. In addition, DFT calculation models based on the X-ray diffraction (XRD) measurements and X-ray photoelectron spectroscopy (XPS) results provided precise water-splitting mechanisms for the fabricated α-Fe2O3 and α-Fe2O3@Rh nanorods. Owing to enhanced carrier generation and hole transfer, the optimum α-Fe2O3@Rh3 sample showed 78% increased photocurrent density, reaching 1.12 mA/cm-2 at 1.23 VRHE compared to that of the pristine α-Fe2O3 nanorods electrode.

Original languageEnglish
Pages (from-to)37290-37299
Number of pages10
JournalACS Applied Materials and Interfaces
Volume15
Issue number31
DOIs
Publication statusPublished - 2023 Aug 9

Bibliographical note

Publisher Copyright:
© 2023 American Chemical Society.

Keywords

  • overpotential
  • oxygen evolution reaction
  • photoelectrochemical water splitting
  • rhodium catalyst
  • α-FeO photoanode

ASJC Scopus subject areas

  • General Materials Science

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