Switching charge transfer of C3N4/W18O49 from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution

Zhen-Feng Huang; Jiajia Song; Xin Wang; Lun Pan; Ke Li; Xiangwen Zhang; Li Wang; Ji-Jun Zou

doi:10.1016/j.nanoen.2017.08.032

Switching charge transfer of C₃N₄/W₁₈O₄₉ from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution

Zhen-Feng Huang, Jiajia Song, Xin Wang, Lun Pan, Ke Li, Xiangwen Zhang, Li Wang, Ji-Jun Zou^*

^*Corresponding author for this work

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

407 Citations (Scopus)

Abstract

Z-scheme composite represents an ideal system for photocatalytic hydrogen evolution, but the charge transfer mechanism is still ambiguous, and how to design and construct such system is a big challenge. Herein, we demonstrate that C₃N₄-W₁₈O₄₉, the type-II composite, can be switched to direct Z-scheme via modulating the interfacial band bending. Experiment and DFT computation results reveal that the adsorption of triethanolamine (TEOA) on C₃N₄ surface significantly uplifts its Femi level, inverses the continuous interfacial band bending to interrupted one, and thus switches the composite from type-II to Z-scheme, without the assistance of any electron shuttles. Importantly, this Z-scheme C₃N₄/W₁₈O₄₉ composites exhibit much better photocatalytic H₂ activity compared with pure C₃N₄, and obtain H₂ evolution rate of 8597 μmol h⁻¹ g⁻¹ (AQY of 39.1% at 420 nm) with Pt as cocatalyst and TEOA as hole scavenger. Also, using this hypothesis we successfully explain why C₃N₄/WO₃ is inherent Z-scheme composite but the performance is not as good as C₃N₄/W₁₈O₄₉ and why TEOA is the best hole scavenger for C₃N₄. This work is expected to give deep insights into understanding the charge transfer in semiconductor composites and rationally designing and constructing Z-scheme photocatalyst for hydrogen evolution. © 2017 Elsevier Ltd

Original language	English
Pages (from-to)	308-316
Journal	Nano Energy
Volume	40
DOIs	https://doi.org/10.1016/j.nanoen.2017.08.032
Publication status	Published - 1 Oct 2017
Externally published	Yes

Bibliographical note

Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].

Research Keywords

Carbon nitride
Hydrogen evolution
Interfacial band bending
Photocatalysis
Tungsten oxide
Z-scheme

UN SDGs

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

Access Output

10.1016/j.nanoen.2017.08.032

Other Access Options

Check CityUHK Library

Permanent Link

Right click to copy link

Cite this

@article{6789bf9242d548959690c05205d801b8,

title = "Switching charge transfer of C3N4/W18O49 from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution",

abstract = "Z-scheme composite represents an ideal system for photocatalytic hydrogen evolution, but the charge transfer mechanism is still ambiguous, and how to design and construct such system is a big challenge. Herein, we demonstrate that C3N4-W18O49, the type-II composite, can be switched to direct Z-scheme via modulating the interfacial band bending. Experiment and DFT computation results reveal that the adsorption of triethanolamine (TEOA) on C3N4 surface significantly uplifts its Femi level, inverses the continuous interfacial band bending to interrupted one, and thus switches the composite from type-II to Z-scheme, without the assistance of any electron shuttles. Importantly, this Z-scheme C3N4/W18O49 composites exhibit much better photocatalytic H2 activity compared with pure C3N4, and obtain H2 evolution rate of 8597 μmol h−1 g−1 (AQY of 39.1% at 420 nm) with Pt as cocatalyst and TEOA as hole scavenger. Also, using this hypothesis we successfully explain why C3N4/WO3 is inherent Z-scheme composite but the performance is not as good as C3N4/W18O49 and why TEOA is the best hole scavenger for C3N4. This work is expected to give deep insights into understanding the charge transfer in semiconductor composites and rationally designing and constructing Z-scheme photocatalyst for hydrogen evolution. {\textcopyright} 2017 Elsevier Ltd",

keywords = "Carbon nitride, Hydrogen evolution, Interfacial band bending, Photocatalysis, Tungsten oxide, Z-scheme",

author = "Zhen-Feng Huang and Jiajia Song and Xin Wang and Lun Pan and Ke Li and Xiangwen Zhang and Li Wang and Ji-Jun Zou",

note = "Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].",

year = "2017",

month = oct,

day = "1",

doi = "10.1016/j.nanoen.2017.08.032",

language = "English",

volume = "40",

pages = "308--316",

journal = "Nano Energy",

issn = "2211-2855",

publisher = "Elsevier B.V.",

}

TY - JOUR

T1 - Switching charge transfer of C3N4/W18O49 from type-II to Z-scheme by interfacial band bending for highly efficient photocatalytic hydrogen evolution

AU - Huang, Zhen-Feng

AU - Song, Jiajia

AU - Wang, Xin

AU - Pan, Lun

AU - Li, Ke

AU - Zhang, Xiangwen

AU - Wang, Li

AU - Zou, Ji-Jun

N1 - Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].

PY - 2017/10/1

Y1 - 2017/10/1

N2 - Z-scheme composite represents an ideal system for photocatalytic hydrogen evolution, but the charge transfer mechanism is still ambiguous, and how to design and construct such system is a big challenge. Herein, we demonstrate that C3N4-W18O49, the type-II composite, can be switched to direct Z-scheme via modulating the interfacial band bending. Experiment and DFT computation results reveal that the adsorption of triethanolamine (TEOA) on C3N4 surface significantly uplifts its Femi level, inverses the continuous interfacial band bending to interrupted one, and thus switches the composite from type-II to Z-scheme, without the assistance of any electron shuttles. Importantly, this Z-scheme C3N4/W18O49 composites exhibit much better photocatalytic H2 activity compared with pure C3N4, and obtain H2 evolution rate of 8597 μmol h−1 g−1 (AQY of 39.1% at 420 nm) with Pt as cocatalyst and TEOA as hole scavenger. Also, using this hypothesis we successfully explain why C3N4/WO3 is inherent Z-scheme composite but the performance is not as good as C3N4/W18O49 and why TEOA is the best hole scavenger for C3N4. This work is expected to give deep insights into understanding the charge transfer in semiconductor composites and rationally designing and constructing Z-scheme photocatalyst for hydrogen evolution. © 2017 Elsevier Ltd

AB - Z-scheme composite represents an ideal system for photocatalytic hydrogen evolution, but the charge transfer mechanism is still ambiguous, and how to design and construct such system is a big challenge. Herein, we demonstrate that C3N4-W18O49, the type-II composite, can be switched to direct Z-scheme via modulating the interfacial band bending. Experiment and DFT computation results reveal that the adsorption of triethanolamine (TEOA) on C3N4 surface significantly uplifts its Femi level, inverses the continuous interfacial band bending to interrupted one, and thus switches the composite from type-II to Z-scheme, without the assistance of any electron shuttles. Importantly, this Z-scheme C3N4/W18O49 composites exhibit much better photocatalytic H2 activity compared with pure C3N4, and obtain H2 evolution rate of 8597 μmol h−1 g−1 (AQY of 39.1% at 420 nm) with Pt as cocatalyst and TEOA as hole scavenger. Also, using this hypothesis we successfully explain why C3N4/WO3 is inherent Z-scheme composite but the performance is not as good as C3N4/W18O49 and why TEOA is the best hole scavenger for C3N4. This work is expected to give deep insights into understanding the charge transfer in semiconductor composites and rationally designing and constructing Z-scheme photocatalyst for hydrogen evolution. © 2017 Elsevier Ltd

KW - Carbon nitride

KW - Hydrogen evolution

KW - Interfacial band bending

KW - Photocatalysis

KW - Tungsten oxide

KW - Z-scheme

UR - http://www.scopus.com/inward/record.url?scp=85027989264&partnerID=8YFLogxK

UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-85027989264&origin=recordpage

U2 - 10.1016/j.nanoen.2017.08.032

DO - 10.1016/j.nanoen.2017.08.032

M3 - RGC 21 - Publication in refereed journal

SN - 2211-2855

VL - 40

SP - 308

EP - 316

JO - Nano Energy

JF - Nano Energy

ER -