Subsurface Ag-modified Bi₃NbO₇: kinetic modulation of photocatalytic oxidation and hydrogen evolution
File(s)
Accepted version
Supporting information
Author(s)
Type
Journal Article
Abstract
Subsurface silver-modified Bi3NbO7 photocatalysts were synthesized via a hydrothermal method to investigate the role of metal spatial distribution in photocatalytic pathways. Integrated structural, physicochemical, spectroscopic and theoretical analyses confirm that Ag is in the subsurface region rather than forming surface nanoparticles or substituting into the Bi3NbO7 lattice, inducing localized distortions without altering the bulk crystal structure or the electronic band structure. Despite these minimal thermodynamic changes, the photocatalytic activities for Rhodamine B degradation and hydrogen evolution vary significantly across samples. Photoelectrochemical and transient absorption spectroscopic studies reveal that the catalytic activities and selectivity are primarily driven by charge carrier kinetics. Specifically, subsurface Ag dispersion modulates the competition between oxidation, governed by hole availability, and reduction, which is sensitive to electron-hole separation efficiency. This study presents a ‘subsurface-mediated kinetic control’ strategy, offering tuneable reaction selectivity through engineering the spatial location of metallic species.
Date Issued
2026-05-15
Date Acceptance
2026-04-27
Citation
Journal of Alloys and Compounds, 2026, 1066
ISSN
0925-8388
Publisher
Elsevier BV
Start Page
188319
End Page
188319
Journal / Book Title
Journal of Alloys and Compounds
Volume
1066
Copyright Statement
Copyright © 2026 Elsevier B.V. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
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Publication Status
Published
Article Number
188319
Date Publish Online
2026-04-28