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Engineering bimetallic CuAu to suppress hydrogen evolution and enhance charge transfer for improved photoelectrochemical nitrogen reduction

Zhang, Fengying LU ; Liu, Yi ; Liu, Jiaxin ; Wu, Haoran ; Jiang, Yuman LU ; Zhou, Haozhi ; Guo, Heng ; Zheng, Kaibo LU ; Yartsev, Arkady LU orcid and Zhou, Ying (2025) In Applied Catalysis B: Environmental 379.
Abstract

Green ammonia synthesis from nitrogen via photocatalysis and electrocatalysis has emerged as a pivotal research focus in sustainable chemical processes. The efficient catalytic reduction of nitrogen necessitates concurrent nitrogen activation and hydrogen evolution suppression, representing a significant challenge. In this study, CuAu bimetallic-modified TiO2 catalysts were developed and engineered to address these issues. By combining structural characterization, ultrafast photophysical studies, and DFT calculations, we demonstrate that adding Cu alters the work function of the metals and, consequently, the Schottky barrier towards TiO2, which influences the photo-induced charge separation efficiency. Furthermore,... (More)

Green ammonia synthesis from nitrogen via photocatalysis and electrocatalysis has emerged as a pivotal research focus in sustainable chemical processes. The efficient catalytic reduction of nitrogen necessitates concurrent nitrogen activation and hydrogen evolution suppression, representing a significant challenge. In this study, CuAu bimetallic-modified TiO2 catalysts were developed and engineered to address these issues. By combining structural characterization, ultrafast photophysical studies, and DFT calculations, we demonstrate that adding Cu alters the work function of the metals and, consequently, the Schottky barrier towards TiO2, which influences the photo-induced charge separation efficiency. Furthermore, Cu-Au binary active sites exhibit a stronger affinity for N atoms, elongating the surface-adsorbed N-N bonds and facilitating bond cleavage. These two phenomena promote the nitrogen activation process. Conversely, the addition of copper reduces the coupling of the H 1 s electron, thereby inhibiting the proton adsorption electron transfer of the *H species. The optimal alloy configuration of Cu(5)Au(5) was found to balance the trade-off between nitrogen activation and hydrogen evolution suppression with maximum catalytic activity. This study reveals the combined effect of a bimetal alloy on charge transfer, nitrogen adsorption activation, and hydrogen evolution, offering insights into the enhancement of nitrogen-to-ammonia conversion.

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author
; ; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Carrier dynamics, Hydrogen evolution inhibition, Nitrogen reduction, Photoelectrocatalysis
in
Applied Catalysis B: Environmental
volume
379
article number
125739
publisher
Elsevier
external identifiers
  • scopus:105011867764
ISSN
0926-3373
DOI
10.1016/j.apcatb.2025.125739
language
English
LU publication?
yes
id
f5a3eb0d-bab4-45c0-829c-84bb5d902c38
date added to LUP
2025-10-24 15:13:43
date last changed
2025-10-24 15:14:37
@article{f5a3eb0d-bab4-45c0-829c-84bb5d902c38,
  abstract     = {{<p>Green ammonia synthesis from nitrogen via photocatalysis and electrocatalysis has emerged as a pivotal research focus in sustainable chemical processes. The efficient catalytic reduction of nitrogen necessitates concurrent nitrogen activation and hydrogen evolution suppression, representing a significant challenge. In this study, CuAu bimetallic-modified TiO<sub>2</sub> catalysts were developed and engineered to address these issues. By combining structural characterization, ultrafast photophysical studies, and DFT calculations, we demonstrate that adding Cu alters the work function of the metals and, consequently, the Schottky barrier towards TiO<sub>2</sub>, which influences the photo-induced charge separation efficiency. Furthermore, Cu-Au binary active sites exhibit a stronger affinity for N atoms, elongating the surface-adsorbed N-N bonds and facilitating bond cleavage. These two phenomena promote the nitrogen activation process. Conversely, the addition of copper reduces the coupling of the H 1 s electron, thereby inhibiting the proton adsorption electron transfer of the *H species. The optimal alloy configuration of Cu<sub>(5)</sub>Au<sub>(5)</sub> was found to balance the trade-off between nitrogen activation and hydrogen evolution suppression with maximum catalytic activity. This study reveals the combined effect of a bimetal alloy on charge transfer, nitrogen adsorption activation, and hydrogen evolution, offering insights into the enhancement of nitrogen-to-ammonia conversion.</p>}},
  author       = {{Zhang, Fengying and Liu, Yi and Liu, Jiaxin and Wu, Haoran and Jiang, Yuman and Zhou, Haozhi and Guo, Heng and Zheng, Kaibo and Yartsev, Arkady and Zhou, Ying}},
  issn         = {{0926-3373}},
  keywords     = {{Carrier dynamics; Hydrogen evolution inhibition; Nitrogen reduction; Photoelectrocatalysis}},
  language     = {{eng}},
  publisher    = {{Elsevier}},
  series       = {{Applied Catalysis B: Environmental}},
  title        = {{Engineering bimetallic CuAu to suppress hydrogen evolution and enhance charge transfer for improved photoelectrochemical nitrogen reduction}},
  url          = {{http://dx.doi.org/10.1016/j.apcatb.2025.125739}},
  doi          = {{10.1016/j.apcatb.2025.125739}},
  volume       = {{379}},
  year         = {{2025}},
}