High-Valent Iron Redox-Mediated Photoelectrochemical Water Oxidation

Tae Hwa Jeon; Seungmok Han; Bupmo Kim; Cheolwoo Park; Wooyul Kim; Hyunwoong Park; Wonyong Choi

doi:10.1021/acsenergylett.1c02430

High-Valent Iron Redox-Mediated Photoelectrochemical Water Oxidation

Tae Hwa Jeon, Seungmok Han, Bupmo Kim, Cheolwoo Park, Wooyul Kim, Hyunwoong Park, Wonyong Choi

School of Energy Engineering

Research output: Contribution to journal › Article › peer-review

10 Scopus citations

Abstract

Fe³⁺ is widely used as a conduction band electron acceptor in the photocatalytic and photoelectrochemical (PEC) oxidation of water and various substrates. However, a question of the possible involvement of Fe³⁺ as a valence band hole acceptor has been raised. Herein, we demonstrate that the PEC water oxidation using oxide semiconductor (WO₃, TiO₂, and BiVO₄; primarily WO₃) films can proceed via the formation of high-valent iron species in the presence of aqueous Fe³⁺ ions at pH 1–3. The presence of Fe³⁺ (1–100 mM) enhances the photocurrent generation, O₂ evolution, and the Faradaic efficiency (FE) of ∼90% with a biased WO₃ electrode (1.23–1.88 V_RHE), whereas the formation of Fe²⁺ is significantly inhibited. An in situ transient absorption spectroscopic analysis reveals the formation of high-valent iron species. The selective oxidation of dimethyl sulfoxide to dimethyl sulfone using in situ high-valent iron species is achieved with an FE of ∼98% in the PEC reaction with Fe³⁺. The proposed reaction mechanism should call for attention to the conventional role of Fe³⁺ in the PEC reaction.

Original language	English
Pages (from-to)	59-66
Number of pages	8
Journal	ACS Energy Letters
Volume	7
Issue number	1
DOIs	https://doi.org/10.1021/acsenergylett.1c02430
State	Published - 14 Jan 2022

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1021/acsenergylett.1c02430

Cite this

@article{a1a56902e3c549928c0730c06a1e515b,

title = "High-Valent Iron Redox-Mediated Photoelectrochemical Water Oxidation",

abstract = "Fe3+ is widely used as a conduction band electron acceptor in the photocatalytic and photoelectrochemical (PEC) oxidation of water and various substrates. However, a question of the possible involvement of Fe3+ as a valence band hole acceptor has been raised. Herein, we demonstrate that the PEC water oxidation using oxide semiconductor (WO3, TiO2, and BiVO4; primarily WO3) films can proceed via the formation of high-valent iron species in the presence of aqueous Fe3+ ions at pH 1–3. The presence of Fe3+ (1–100 mM) enhances the photocurrent generation, O2 evolution, and the Faradaic efficiency (FE) of ∼90% with a biased WO3 electrode (1.23–1.88 VRHE), whereas the formation of Fe2+ is significantly inhibited. An in situ transient absorption spectroscopic analysis reveals the formation of high-valent iron species. The selective oxidation of dimethyl sulfoxide to dimethyl sulfone using in situ high-valent iron species is achieved with an FE of ∼98% in the PEC reaction with Fe3+. The proposed reaction mechanism should call for attention to the conventional role of Fe3+ in the PEC reaction.",

author = "Jeon, {Tae Hwa} and Seungmok Han and Bupmo Kim and Cheolwoo Park and Wooyul Kim and Hyunwoong Park and Wonyong Choi",

note = "Publisher Copyright: {\textcopyright} 2021 American Chemical Society",

year = "2022",

month = jan,

day = "14",

doi = "10.1021/acsenergylett.1c02430",

language = "English",

volume = "7",

pages = "59--66",

journal = "ACS Energy Letters",

issn = "2380-8195",

publisher = "American Chemical Society",

number = "1",

}

TY - JOUR

T1 - High-Valent Iron Redox-Mediated Photoelectrochemical Water Oxidation

AU - Jeon, Tae Hwa

AU - Han, Seungmok

AU - Kim, Bupmo

AU - Park, Cheolwoo

AU - Kim, Wooyul

AU - Park, Hyunwoong

AU - Choi, Wonyong

PY - 2022/1/14

Y1 - 2022/1/14

N2 - Fe3+ is widely used as a conduction band electron acceptor in the photocatalytic and photoelectrochemical (PEC) oxidation of water and various substrates. However, a question of the possible involvement of Fe3+ as a valence band hole acceptor has been raised. Herein, we demonstrate that the PEC water oxidation using oxide semiconductor (WO3, TiO2, and BiVO4; primarily WO3) films can proceed via the formation of high-valent iron species in the presence of aqueous Fe3+ ions at pH 1–3. The presence of Fe3+ (1–100 mM) enhances the photocurrent generation, O2 evolution, and the Faradaic efficiency (FE) of ∼90% with a biased WO3 electrode (1.23–1.88 VRHE), whereas the formation of Fe2+ is significantly inhibited. An in situ transient absorption spectroscopic analysis reveals the formation of high-valent iron species. The selective oxidation of dimethyl sulfoxide to dimethyl sulfone using in situ high-valent iron species is achieved with an FE of ∼98% in the PEC reaction with Fe3+. The proposed reaction mechanism should call for attention to the conventional role of Fe3+ in the PEC reaction.

AB - Fe3+ is widely used as a conduction band electron acceptor in the photocatalytic and photoelectrochemical (PEC) oxidation of water and various substrates. However, a question of the possible involvement of Fe3+ as a valence band hole acceptor has been raised. Herein, we demonstrate that the PEC water oxidation using oxide semiconductor (WO3, TiO2, and BiVO4; primarily WO3) films can proceed via the formation of high-valent iron species in the presence of aqueous Fe3+ ions at pH 1–3. The presence of Fe3+ (1–100 mM) enhances the photocurrent generation, O2 evolution, and the Faradaic efficiency (FE) of ∼90% with a biased WO3 electrode (1.23–1.88 VRHE), whereas the formation of Fe2+ is significantly inhibited. An in situ transient absorption spectroscopic analysis reveals the formation of high-valent iron species. The selective oxidation of dimethyl sulfoxide to dimethyl sulfone using in situ high-valent iron species is achieved with an FE of ∼98% in the PEC reaction with Fe3+. The proposed reaction mechanism should call for attention to the conventional role of Fe3+ in the PEC reaction.

UR - http://www.scopus.com/inward/record.url?scp=85121003186&partnerID=8YFLogxK

U2 - 10.1021/acsenergylett.1c02430

DO - 10.1021/acsenergylett.1c02430

M3 - Article

AN - SCOPUS:85121003186

SN - 2380-8195

VL - 7

SP - 59

EP - 66

JO - ACS Energy Letters

JF - ACS Energy Letters

IS - 1

ER -

High-Valent Iron Redox-Mediated Photoelectrochemical Water Oxidation

Abstract

UN SDGs

Access to Document

Other files and links

Fingerprint

Cite this