Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Inorganic ligands-mediated hole attraction and surface structuralreorganization in InP/ZnS QD photocatalysts studied via ultrafast visibleand midinfrared spectroscopies

Liu, Yang LU ; Zhou, Ying ; Abdellah, Mohamed ; Lin, Weihua LU ; Meng, Jie LU ; Zhao, Qian ; Yu, Shan ; Xie, Zhanghui ; Pan, Qinying and Zhang, Fengying LU , et al. (2022) In SCIENCE CHINA Materials 65(9). p.2529-2539
Abstract

Photoinduced carrier dynamical processes dominate the optical excitation properties of photocatalysts and further determine the photocatalytic performance. In addition, as the electrons generally possess a faster transfer rate than holes, hole transfer and accumulation are critical, and they play the key efficiency-limiting step during the photocatalytic process. Therefore, a comprehensive understanding of the dynamics of photogenerated holes and their determining factors in the photocatalytic system is highly essential to rationalize the full catalytic mechanism and develop highly efficient photocatalysts, which have not yet been revealed. In this work, the photoinduced charge carrier dynamics in InP/ZnS quantum dots (QDs) capped with... (More)

Photoinduced carrier dynamical processes dominate the optical excitation properties of photocatalysts and further determine the photocatalytic performance. In addition, as the electrons generally possess a faster transfer rate than holes, hole transfer and accumulation are critical, and they play the key efficiency-limiting step during the photocatalytic process. Therefore, a comprehensive understanding of the dynamics of photogenerated holes and their determining factors in the photocatalytic system is highly essential to rationalize the full catalytic mechanism and develop highly efficient photocatalysts, which have not yet been revealed. In this work, the photoinduced charge carrier dynamics in InP/ZnS quantum dots (QDs) capped with long-chain L-typed ligands (oleylamine) and inorganic ligands (sulfide ion (S2−)) were explored. Time-resolved photoluminescence and femtosecond transient-absorption spectroscopy unambiguously confirmed the ultrafast hole transfer from the InP core to S2− ligands. Moreover, by probing the bleach of vibrational stretching of the ligands with transient midinfrared absorption spectroscopy, the hole transfer time was determined to be 4.2 ps. The injected holes are long-lived at the S2− ligands (>4.5 ns), and they can remove electrostatically attached surfactants to compensate for the spatial charge redistribution. Finally, compared with other inorganic ligands such as Cl− and PO43−, S2− balances the ionic radii and net charge to ensure the optimal condition for charge transfer. Such observation rationalizes the excellent photocatalytic H2 evolution (213.6 µmol mg−1 within 10 h) in InP/ZnS QDs capped with S2− compared with those capped with other ligands and elucidates the role of surface ligands in the photocatalytic activity of colloidal QDs.

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
hole transfer, InP/ZnS QD photocatalysts, midinfrared spectroscopies, surface ligands, ultrafast visible spectroscopies
in
SCIENCE CHINA Materials
volume
65
issue
9
pages
2529 - 2539
publisher
Science in China Press
external identifiers
  • scopus:85127557519
ISSN
2095-8226
DOI
10.1007/s40843-021-1992-3
language
English
LU publication?
yes
id
e76fcc34-e998-4613-84f9-67275ee4fa8c
date added to LUP
2022-06-07 12:18:13
date last changed
2023-11-21 01:47:35
@article{e76fcc34-e998-4613-84f9-67275ee4fa8c,
  abstract     = {{<p>Photoinduced carrier dynamical processes dominate the optical excitation properties of photocatalysts and further determine the photocatalytic performance. In addition, as the electrons generally possess a faster transfer rate than holes, hole transfer and accumulation are critical, and they play the key efficiency-limiting step during the photocatalytic process. Therefore, a comprehensive understanding of the dynamics of photogenerated holes and their determining factors in the photocatalytic system is highly essential to rationalize the full catalytic mechanism and develop highly efficient photocatalysts, which have not yet been revealed. In this work, the photoinduced charge carrier dynamics in InP/ZnS quantum dots (QDs) capped with long-chain L-typed ligands (oleylamine) and inorganic ligands (sulfide ion (S<sup>2−</sup>)) were explored. Time-resolved photoluminescence and femtosecond transient-absorption spectroscopy unambiguously confirmed the ultrafast hole transfer from the InP core to S<sup>2−</sup> ligands. Moreover, by probing the bleach of vibrational stretching of the ligands with transient midinfrared absorption spectroscopy, the hole transfer time was determined to be 4.2 ps. The injected holes are long-lived at the S<sup>2−</sup> ligands (&gt;4.5 ns), and they can remove electrostatically attached surfactants to compensate for the spatial charge redistribution. Finally, compared with other inorganic ligands such as Cl<sup>−</sup> and PO<sub>4</sub><sup>3−</sup>, S<sup>2−</sup> balances the ionic radii and net charge to ensure the optimal condition for charge transfer. Such observation rationalizes the excellent photocatalytic H<sub>2</sub> evolution (213.6 µmol mg<sup>−1</sup> within 10 h) in InP/ZnS QDs capped with S<sup>2−</sup> compared with those capped with other ligands and elucidates the role of surface ligands in the photocatalytic activity of colloidal QDs.</p>}},
  author       = {{Liu, Yang and Zhou, Ying and Abdellah, Mohamed and Lin, Weihua and Meng, Jie and Zhao, Qian and Yu, Shan and Xie, Zhanghui and Pan, Qinying and Zhang, Fengying and Pullerits, Tonu and Zheng, Kaibo}},
  issn         = {{2095-8226}},
  keywords     = {{hole transfer; InP/ZnS QD photocatalysts; midinfrared spectroscopies; surface ligands; ultrafast visible spectroscopies}},
  language     = {{eng}},
  number       = {{9}},
  pages        = {{2529--2539}},
  publisher    = {{Science in China Press}},
  series       = {{SCIENCE CHINA Materials}},
  title        = {{Inorganic ligands-mediated hole attraction and surface structuralreorganization in InP/ZnS QD photocatalysts studied via ultrafast visibleand midinfrared spectroscopies}},
  url          = {{http://dx.doi.org/10.1007/s40843-021-1992-3}},
  doi          = {{10.1007/s40843-021-1992-3}},
  volume       = {{65}},
  year         = {{2022}},
}