Visible-Light-Driven Photocatalytic Hydrogen Generation on Nanosized TiO2-II Stabilized by High-Pressure Torsion

Hadi Razavi-Khosroshahi; Kaveh Edalati; Masashige Hirayama; Hoda Emami; Makoto Arita; Miho Yamauchi; Hidehisa Hagiwara; Shintaro Ida; Tatsumi Ishihara; Etsuo Akiba; Zenji Horita; Masayoshi Fuji

doi:10.1021/acscatal.6b01482

Visible-Light-Driven Photocatalytic Hydrogen Generation on Nanosized TiO₂-II Stabilized by High-Pressure Torsion

Hadi Razavi-Khosroshahi, Kaveh Edalati, Masashige Hirayama, Hoda Emami, Makoto Arita, Miho Yamauchi, Hidehisa Hagiwara, Shintaro Ida, Tatsumi Ishihara, Etsuo Akiba, Zenji Horita, Masayoshi Fuji

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

61 Citations (Scopus)

Abstract

Photocatalytic activity of pure TiO₂ is limited to ultraviolet (UV) light due to the wide bandgap of anatase and rutile phases. The bandgap of high-pressure phases of TiO₂ can theoretically coincide with visible light, but these phases are unstable at ambient pressure. In this work, the high-pressure TiO₂-II (columbite) phase with large fractions of oxygen vacancies was stabilized by inducing plastic strain to anatase under 6 GPa. The material could absorb visible light as a consequence of bandgap narrowing by â14 0.7 eV. Formation of nanosized TiO₂-II enhanced the hydrogen generation efficiency under visible light, and the efficiency improved after removing the oxygen vacancies by annealing.

Original language	English
Pages (from-to)	5103-5107
Number of pages	5
Journal	ACS Catalysis
Volume	6
Issue number	8
DOIs	https://doi.org/10.1021/acscatal.6b01482
Publication status	Published - 2016 Aug 5
Externally published	Yes

Keywords

TiO-II (columbite)
high-pressure torsion (HPT)
hydrogen generation
severe plastic deformation (SPD)
titanium oxide (titania)
visible-light-active photocatalyst

ASJC Scopus subject areas

Catalysis
Chemistry(all)

Access to Document

10.1021/acscatal.6b01482

Cite this

@article{ba8bec28e9e2425a84396085184f95ec,

title = "Visible-Light-Driven Photocatalytic Hydrogen Generation on Nanosized TiO2-II Stabilized by High-Pressure Torsion",

abstract = "Photocatalytic activity of pure TiO2 is limited to ultraviolet (UV) light due to the wide bandgap of anatase and rutile phases. The bandgap of high-pressure phases of TiO2 can theoretically coincide with visible light, but these phases are unstable at ambient pressure. In this work, the high-pressure TiO2-II (columbite) phase with large fractions of oxygen vacancies was stabilized by inducing plastic strain to anatase under 6 GPa. The material could absorb visible light as a consequence of bandgap narrowing by {\^a}14 0.7 eV. Formation of nanosized TiO2-II enhanced the hydrogen generation efficiency under visible light, and the efficiency improved after removing the oxygen vacancies by annealing.",

keywords = "TiO-II (columbite), high-pressure torsion (HPT), hydrogen generation, severe plastic deformation (SPD), titanium oxide (titania), visible-light-active photocatalyst",

author = "Hadi Razavi-Khosroshahi and Kaveh Edalati and Masashige Hirayama and Hoda Emami and Makoto Arita and Miho Yamauchi and Hidehisa Hagiwara and Shintaro Ida and Tatsumi Ishihara and Etsuo Akiba and Zenji Horita and Masayoshi Fuji",

note = "Publisher Copyright: {\textcopyright} 2016 American Chemical Society.",

year = "2016",

month = aug,

day = "5",

doi = "10.1021/acscatal.6b01482",

language = "English",

volume = "6",

pages = "5103--5107",

journal = "ACS Catalysis",

issn = "2155-5435",

publisher = "American Chemical Society",

number = "8",

}

TY - JOUR

T1 - Visible-Light-Driven Photocatalytic Hydrogen Generation on Nanosized TiO2-II Stabilized by High-Pressure Torsion

AU - Razavi-Khosroshahi, Hadi

AU - Edalati, Kaveh

AU - Hirayama, Masashige

AU - Emami, Hoda

AU - Arita, Makoto

AU - Yamauchi, Miho

AU - Hagiwara, Hidehisa

AU - Ida, Shintaro

AU - Ishihara, Tatsumi

AU - Akiba, Etsuo

AU - Horita, Zenji

AU - Fuji, Masayoshi

PY - 2016/8/5

Y1 - 2016/8/5

N2 - Photocatalytic activity of pure TiO2 is limited to ultraviolet (UV) light due to the wide bandgap of anatase and rutile phases. The bandgap of high-pressure phases of TiO2 can theoretically coincide with visible light, but these phases are unstable at ambient pressure. In this work, the high-pressure TiO2-II (columbite) phase with large fractions of oxygen vacancies was stabilized by inducing plastic strain to anatase under 6 GPa. The material could absorb visible light as a consequence of bandgap narrowing by â14 0.7 eV. Formation of nanosized TiO2-II enhanced the hydrogen generation efficiency under visible light, and the efficiency improved after removing the oxygen vacancies by annealing.

AB - Photocatalytic activity of pure TiO2 is limited to ultraviolet (UV) light due to the wide bandgap of anatase and rutile phases. The bandgap of high-pressure phases of TiO2 can theoretically coincide with visible light, but these phases are unstable at ambient pressure. In this work, the high-pressure TiO2-II (columbite) phase with large fractions of oxygen vacancies was stabilized by inducing plastic strain to anatase under 6 GPa. The material could absorb visible light as a consequence of bandgap narrowing by â14 0.7 eV. Formation of nanosized TiO2-II enhanced the hydrogen generation efficiency under visible light, and the efficiency improved after removing the oxygen vacancies by annealing.

KW - TiO-II (columbite)

KW - high-pressure torsion (HPT)

KW - hydrogen generation

KW - severe plastic deformation (SPD)

KW - titanium oxide (titania)

KW - visible-light-active photocatalyst

UR - http://www.scopus.com/inward/record.url?scp=84981320755&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84981320755&partnerID=8YFLogxK

U2 - 10.1021/acscatal.6b01482

DO - 10.1021/acscatal.6b01482

M3 - Article

AN - SCOPUS:84981320755

SN - 2155-5435

VL - 6

SP - 5103

EP - 5107

JO - ACS Catalysis

JF - ACS Catalysis

IS - 8

ER -