Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity

The rise in nitrogen-containing compounds in water sources due to modern agricultural practices has intensified the need to effectively convert nitrate to ammonia, a valuable fertiliser and fuel. We developed a photo-assisted electrocatalytic system using a NiO/Au plasmon/TiO2 composite to selective...

Full description

Saved in:
Bibliographic Details
Main Authors: Vitor R. Silveira, Daniel F. Fernandes, Robert Bericat-Vadell, Tomas Edvinsson, Tomas Kubart, Jacinto Sá
Format: Article
Language:English
Published: Elsevier 2024-12-01
Series:Applied Catalysis O: Open
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2950648424001032
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850061156590288896
author Vitor R. Silveira
Daniel F. Fernandes
Robert Bericat-Vadell
Tomas Edvinsson
Tomas Kubart
Jacinto Sá
author_facet Vitor R. Silveira
Daniel F. Fernandes
Robert Bericat-Vadell
Tomas Edvinsson
Tomas Kubart
Jacinto Sá
author_sort Vitor R. Silveira
collection DOAJ
description The rise in nitrogen-containing compounds in water sources due to modern agricultural practices has intensified the need to effectively convert nitrate to ammonia, a valuable fertiliser and fuel. We developed a photo-assisted electrocatalytic system using a NiO/Au plasmon/TiO2 composite to selectively reduce nitrate to ammonia under visible light, at neutral pH, and at room temperature. TiO2 was found to be the active catalyst, but the precise active structure responsible for each catalytic step remains unclear, as the reaction involves a complex, multistep process. By analyzing the catalytic activity of different TiO2 phases, we found that amorphous TiO2 significantly enhances the nitrate-to-nitrite reduction step, increasing nitrite concentration in solution by nearly 50 % and resulting in a 10 % increase in Faradaic efficiency for this product. Conversely, the rutile phase plays a crucial role in the subsequent conversion of nitrite to ammonia. When the rutile phase was present, the ammonia yield more than doubled, leading to a 30 % increase in Faradaic efficiency. This phase-dependent behaviour provides critical insights into improving nitrate reduction efficiency, enabling sustainable agricultural practices that recycle nutrients, reduce fertiliser costs, and promote economic sustainability.
format Article
id doaj-art-fd11849e09ba4132884f2af9e23430ec
institution DOAJ
issn 2950-6484
language English
publishDate 2024-12-01
publisher Elsevier
record_format Article
series Applied Catalysis O: Open
spelling doaj-art-fd11849e09ba4132884f2af9e23430ec2025-08-20T02:50:20ZengElsevierApplied Catalysis O: Open2950-64842024-12-0119720701710.1016/j.apcato.2024.207017Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activityVitor R. Silveira0Daniel F. Fernandes1Robert Bericat-Vadell2Tomas Edvinsson3Tomas Kubart4Jacinto Sá5Physical Chemistry Division, Department of Chemistry - Angstrom Laboratory, Uppsala University, 751 20 Uppsala, SwedenDivision of Solid-State Electronics, Department of Electrical Engineering, Ångström Laboratory, Uppsala University, 751 03 Uppsala, SwedenPhysical Chemistry Division, Department of Chemistry - Angstrom Laboratory, Uppsala University, 751 20 Uppsala, SwedenDivision of Solid-State Physics, Department of Materials Science and Engineering, Ångström Laboratory, Uppsala University, 751 03 Uppsala, SwedenDivision of Solid-State Electronics, Department of Electrical Engineering, Ångström Laboratory, Uppsala University, 751 03 Uppsala, SwedenPhysical Chemistry Division, Department of Chemistry - Angstrom Laboratory, Uppsala University, 751 20 Uppsala, Sweden; Institution Institute of Physical Chemistry, Polish Academy of Sciences, Marcina Kasprzaka 44/52, 01-224 Warsaw, Poland; Corresponding author at: Physical Chemistry Division, Department of Chemistry - Angstrom Laboratory, Uppsala University, 751 20 Uppsala, Sweden.The rise in nitrogen-containing compounds in water sources due to modern agricultural practices has intensified the need to effectively convert nitrate to ammonia, a valuable fertiliser and fuel. We developed a photo-assisted electrocatalytic system using a NiO/Au plasmon/TiO2 composite to selectively reduce nitrate to ammonia under visible light, at neutral pH, and at room temperature. TiO2 was found to be the active catalyst, but the precise active structure responsible for each catalytic step remains unclear, as the reaction involves a complex, multistep process. By analyzing the catalytic activity of different TiO2 phases, we found that amorphous TiO2 significantly enhances the nitrate-to-nitrite reduction step, increasing nitrite concentration in solution by nearly 50 % and resulting in a 10 % increase in Faradaic efficiency for this product. Conversely, the rutile phase plays a crucial role in the subsequent conversion of nitrite to ammonia. When the rutile phase was present, the ammonia yield more than doubled, leading to a 30 % increase in Faradaic efficiency. This phase-dependent behaviour provides critical insights into improving nitrate reduction efficiency, enabling sustainable agricultural practices that recycle nutrients, reduce fertiliser costs, and promote economic sustainability.http://www.sciencedirect.com/science/article/pii/S2950648424001032Nitrate-to-ammoniaPhoto-assisted electrocatalysisCatalyst active phaseSustainable and recyclable production of fertilisers
spellingShingle Vitor R. Silveira
Daniel F. Fernandes
Robert Bericat-Vadell
Tomas Edvinsson
Tomas Kubart
Jacinto Sá
Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity
Applied Catalysis O: Open
Nitrate-to-ammonia
Photo-assisted electrocatalysis
Catalyst active phase
Sustainable and recyclable production of fertilisers
title Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity
title_full Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity
title_fullStr Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity
title_full_unstemmed Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity
title_short Phase-dependent photo-assisted electrocatalytic conversion of nitrate to ammonia using TiO2: Insights into amorphous and rutile activity
title_sort phase dependent photo assisted electrocatalytic conversion of nitrate to ammonia using tio2 insights into amorphous and rutile activity
topic Nitrate-to-ammonia
Photo-assisted electrocatalysis
Catalyst active phase
Sustainable and recyclable production of fertilisers
url http://www.sciencedirect.com/science/article/pii/S2950648424001032
work_keys_str_mv AT vitorrsilveira phasedependentphotoassistedelectrocatalyticconversionofnitratetoammoniausingtio2insightsintoamorphousandrutileactivity
AT danielffernandes phasedependentphotoassistedelectrocatalyticconversionofnitratetoammoniausingtio2insightsintoamorphousandrutileactivity
AT robertbericatvadell phasedependentphotoassistedelectrocatalyticconversionofnitratetoammoniausingtio2insightsintoamorphousandrutileactivity
AT tomasedvinsson phasedependentphotoassistedelectrocatalyticconversionofnitratetoammoniausingtio2insightsintoamorphousandrutileactivity
AT tomaskubart phasedependentphotoassistedelectrocatalyticconversionofnitratetoammoniausingtio2insightsintoamorphousandrutileactivity
AT jacintosa phasedependentphotoassistedelectrocatalyticconversionofnitratetoammoniausingtio2insightsintoamorphousandrutileactivity