TY - JOUR
T1 - Enhancement of UV-responsive photocatalysts aided by visible-light responsive photocatalysts
T2 - Role of WO3 for H2 evolution on CuCl
AU - Takagi, Masaki
AU - Kawaguchi, Masayuki
AU - Yamakata, Akira
N1 - Funding Information:
This work was supported by a Grant-in-Aid for Basic Research (B) ( 19H02820 ) and Scientific Research on Innovative Areas (Mixed Anion: 19H04708 ), the Strategic Research Infrastructure Project of MEXT , and the Cooperative Research Program of Institute for Catalysis, Hokkaido University ( 17A1001 ). Appendix A
Funding Information:
This work was supported by a Grant-in-Aid for Basic Research (B) (19H02820) and Scientific Research on Innovative Areas (Mixed Anion: 19H04708), the Strategic Research Infrastructure Project of MEXT, and the Cooperative Research Program of Institute for Catalysis, Hokkaido University (17A1001).
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2020/4
Y1 - 2020/4
N2 - WO3 is one of the most popular materials for visible-light photocatalysts. However, its conduction band minimum is too low for water reduction. Here, we found that WO3 can assist water reduction by using visible light in a CuCl2 aqueous solution. Photoirradiation of WO3 in CuCl2 reduces Cu2+ to form indissoluble CuCl adducts, and as-produced CuCl/WO3 was active for H2 evolution under UV-light. This composite has very low reactivity under visible light (>400 nm), but visible-light assisted H2 evolution was observed with simultaneous irradiation with UV light: the activity was increased ∼1.7 fold. Transient absorption measurements revealed that Z-schematic recombination initially takes place between photogenerated electrons in WO3 and holes in CuCl. As a result, the lifetime of electrons in CuCl was increased, enhancing H2 evolution. These results demonstrate that inactive narrow-band gap materials can be used to enhance the activity of wide-band gap materials under sunlight illumination.
AB - WO3 is one of the most popular materials for visible-light photocatalysts. However, its conduction band minimum is too low for water reduction. Here, we found that WO3 can assist water reduction by using visible light in a CuCl2 aqueous solution. Photoirradiation of WO3 in CuCl2 reduces Cu2+ to form indissoluble CuCl adducts, and as-produced CuCl/WO3 was active for H2 evolution under UV-light. This composite has very low reactivity under visible light (>400 nm), but visible-light assisted H2 evolution was observed with simultaneous irradiation with UV light: the activity was increased ∼1.7 fold. Transient absorption measurements revealed that Z-schematic recombination initially takes place between photogenerated electrons in WO3 and holes in CuCl. As a result, the lifetime of electrons in CuCl was increased, enhancing H2 evolution. These results demonstrate that inactive narrow-band gap materials can be used to enhance the activity of wide-band gap materials under sunlight illumination.
KW - Charge carrier dynamics
KW - CuCl
KW - H evolution
KW - WO
KW - Z-Scheme photocatalysis
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U2 - 10.1016/j.apcatb.2019.118333
DO - 10.1016/j.apcatb.2019.118333
M3 - Article
AN - SCOPUS:85075453829
SN - 0926-3373
VL - 263
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
M1 - 118333
ER -