Boosting Photocatalytic N2 Reduction via Ligand-Engineered MOFs : Regulated Hole Utilization and Interfacial Water Coordination for Efficient Proton Supply
(2026) In ACS Nano 20(22). p.16305-16315- Abstract
Photocatalytic nitrogen reduction requires the concerted transfer of six electrons and six protons, where inefficient electron utilization and proton supply represent the critical limiting factors for proton-coupled electron transfer in this process. A key challenge lies in hole accumulation within photocatalysts, as hole transfer typically proceeds 2 to 3 orders of magnitude more slowly than electron transfer. This imbalance leads to charge recombination and sluggish water oxidation, limiting proton availability. In this work, we address these issues by engineering the ligands of metal–organic frameworks (MOFs) to serve as oxidation sites, enabling the simultaneous enhancement of hole extraction and water activation. In... (More)
Photocatalytic nitrogen reduction requires the concerted transfer of six electrons and six protons, where inefficient electron utilization and proton supply represent the critical limiting factors for proton-coupled electron transfer in this process. A key challenge lies in hole accumulation within photocatalysts, as hole transfer typically proceeds 2 to 3 orders of magnitude more slowly than electron transfer. This imbalance leads to charge recombination and sluggish water oxidation, limiting proton availability. In this work, we address these issues by engineering the ligands of metal–organic frameworks (MOFs) to serve as oxidation sites, enabling the simultaneous enhancement of hole extraction and water activation. In sulfonic-acid-functionalized MIL-101(Fe) (MIL-101(Fe)-SO3H), transient absorption spectroscopy (TAS) elucidates that photoinduced electrons are either efficiently injected to the metal center (∼986 ps) or trapped at defect states (∼9 ps), while the holes remain on organic ligands to drive water oxidation. Crucially, −SO3H groups restructure the interfacial water coordination to asymmetric configurations, facilitating the water dissociation and enhancing proton generation. Hence, MIL-101(Fe)-SO3H achieves an impressive NH3 selectivity (98.8%), surpassing that of pristine MIL-101(Fe). This work provides a rational strategy for boosting nitrogen reduction by engineering oxidation sites to promote the proton supply via coordinated control of charge transfer and water activation.
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- author
- Jiang, Yuman LU ; Zhang, Fengying LU ; Mei, Yanglin ; Li, Yong LU ; Zheng, Kaibo LU ; Xu, Hong ; Guo, Heng ; Pullerits, Tonu LU and Zhou, Ying
- organization
- publishing date
- 2026-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- asymmetric hydrogen-bond networks, hole utilization, ligand engineering, metal−organic frameworks, photocatalytic nitrogen reduction
- in
- ACS Nano
- volume
- 20
- issue
- 22
- pages
- 11 pages
- publisher
- The American Chemical Society (ACS)
- external identifiers
-
- pmid:42190163
- scopus:105041299507
- ISSN
- 1936-0851
- DOI
- 10.1021/acsnano.6c03885
- language
- English
- LU publication?
- yes
- id
- 52c3d8c1-eec1-4fbc-9cfd-03130bcbb8aa
- date added to LUP
- 2026-09-10 15:13:35
- date last changed
- 2026-09-10 15:14:22
@article{52c3d8c1-eec1-4fbc-9cfd-03130bcbb8aa,
abstract = {{<p>Photocatalytic nitrogen reduction requires the concerted transfer of six electrons and six protons, where inefficient electron utilization and proton supply represent the critical limiting factors for proton-coupled electron transfer in this process. A key challenge lies in hole accumulation within photocatalysts, as hole transfer typically proceeds 2 to 3 orders of magnitude more slowly than electron transfer. This imbalance leads to charge recombination and sluggish water oxidation, limiting proton availability. In this work, we address these issues by engineering the ligands of metal–organic frameworks (MOFs) to serve as oxidation sites, enabling the simultaneous enhancement of hole extraction and water activation. In sulfonic-acid-functionalized MIL-101(Fe) (MIL-101(Fe)-SO<sub>3</sub>H), transient absorption spectroscopy (TAS) elucidates that photoinduced electrons are either efficiently injected to the metal center (∼986 ps) or trapped at defect states (∼9 ps), while the holes remain on organic ligands to drive water oxidation. Crucially, −SO<sub>3</sub>H groups restructure the interfacial water coordination to asymmetric configurations, facilitating the water dissociation and enhancing proton generation. Hence, MIL-101(Fe)-SO<sub>3</sub>H achieves an impressive NH<sub>3</sub> selectivity (98.8%), surpassing that of pristine MIL-101(Fe). This work provides a rational strategy for boosting nitrogen reduction by engineering oxidation sites to promote the proton supply via coordinated control of charge transfer and water activation.</p>}},
author = {{Jiang, Yuman and Zhang, Fengying and Mei, Yanglin and Li, Yong and Zheng, Kaibo and Xu, Hong and Guo, Heng and Pullerits, Tonu and Zhou, Ying}},
issn = {{1936-0851}},
keywords = {{asymmetric hydrogen-bond networks; hole utilization; ligand engineering; metal−organic frameworks; photocatalytic nitrogen reduction}},
language = {{eng}},
number = {{22}},
pages = {{16305--16315}},
publisher = {{The American Chemical Society (ACS)}},
series = {{ACS Nano}},
title = {{Boosting Photocatalytic N<sub>2</sub> Reduction via Ligand-Engineered MOFs : Regulated Hole Utilization and Interfacial Water Coordination for Efficient Proton Supply}},
url = {{http://dx.doi.org/10.1021/acsnano.6c03885}},
doi = {{10.1021/acsnano.6c03885}},
volume = {{20}},
year = {{2026}},
}