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Chatzitakis, Athanasios; Zhu, Junjie; Gudmundsdottir, Jonina Björg; Strandbakke, Ragnar; Both, Kevin Gregor & Aarholt, Thomas
[Show all 12 contributors for this article]
(2022).
A monolithic and noble metal-free photoelectrochemical device of minimal engineering for efficient, unassisted water splitting.
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Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein
[Show all 9 contributors for this article]
(2022).
Exsolved nanoparticles, galvanically restructured for tunable photo-electrocatalytic energy conversion.
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Both, Kevin Gregor; Reinertsen, Vilde Mari; Kang, Xiaolan; Aarholt, Thomas; Neagu, Dragos & Prytz, Øystein
[Show all 8 contributors for this article]
(2022).
Improved Photoelectrochemical Performance of SrTiO3 by Plasmonically Active Au Nanoparticles.
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Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein
[Show all 9 contributors for this article]
(2022).
Galvanic Restructuring of Exsolved Nanoparticles for Plasmonic and Electrocatalytic Energy Conversion (Small 29/2022 Inside back cover feature).
Small.
ISSN 1613-6810.
18(29).
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Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein
[Show all 9 contributors for this article]
(2022).
Galvanic restructuring of exsolved nanoparticles for plasmonic and electrocatalytic energy conversion
.
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Aarholt, Thomas; Both, Kevin Gregor; Reinertsen, Vilde Mari & Prytz, Øystein
(2021).
Surface plasmon investigations by STEM-EELS mapping of Au/Ni nanoparticles on STO.
Show summary
Metallic nanoparticles have traditionally had sharp absorption peaks between 1 and 5 eV due to the
excitation of surface plasmons. Localized surface plasmon resonance (LSPR) is the coherent oscillation
of quasi-free electrons excited by the electromagnetic fields of a photon or fast electron1,2. Since the
absorption peak energies are in the range of visible light, surface plasmons present a potential pathway
for absorbing energy to drive photoelectrochemical reactions or contribute to photovoltaic applications.
For driving photoelectrochemical reactions, one difficulty is placing photoactive nanoparticles near the
catalyst responsible for a chosen reaction, for example, water splitting. The ideal semiconductor for water
splitting has a bandgap of 1.9 – 2.3 eV, although semiconductors in this range are seldom stable during
photocatalytic water splitting3. Utilizing plasmonics in wide bandgap semiconductors is a promising
alternative, avoiding the stability issue3. In this work, we present a STEM-EELS study of Au nanoparticles
created by galvanic replacement of Ni nanoparticles grown by exsolution of a PLD-deposited thin-film of
A-site excess strontium titanate (Sr1.07Ti 0.93Ni0.07O 3-δ) (STO). STO is an indirect, wide bandgap (3.2
eV) perovskite, studied as a promising photocatalyst for water splitting 4. Ni can easily substitute the Ti
in the STO, making it a suitable candidate for exsolution, while Au cannot substitute Ti5. Simultaneously,
Ni nanoparticles barely show any plasmonic activities, while Au particles are second only to Ag
nanoparticles6. The presented manufacturing technique results in nanoparticles of gold and nickel
freestanding, but socketed, on the surface and embedded in the bulk, with diameters between 50 and 100
nm, which are well-suited for plasmonic applications.
As a starting point, STEM-EELS was performed with a monochromated 300kV STEM probe with ZeroLoss Peak (ZLP) full-width at half-maximum of 110 meV on an FEI Titan G2. A peculiarly shaped gold
nanocluster was studied. After removing the ZLP, the spectrum image was linearly fitted with Gaussians
centered at 1.46, 1.95, and 2.40 eV. The 2.40 eV peak is a well-known Au surface plasmon, whereas the
remaining two are investigated in conjunction with modeling approaches. An RGB composite of the fit
results can be seen in figure 1. Spectra extracted from the coloured regions can be seen in figure 2.
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Kjeldby, Snorre Braathen; Azarov, Alexander; Aarholt, Thomas; Prytz, Øystein & Vines, Lasse
(2021).
Defect-annealing in Si+-implanted β-Ga2O3.
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Nord, Magnus Kristofer; Aarholt, Thomas; O’Connell, Eoghan & Slater, Tom
(2021).
Atomap 0.3.0 release.
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Aarholt, Thomas
(2020).
Transmission Electron Microscopy for Advanced Functional Materials.
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Aarholt, Thomas
(2020).
International Webinar on Sample Preparation for TEM and Data Analysis.
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Aarholt, Thomas
(2020).
Imaging Nanomaterials with Transmission Electron Microscopy.
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Aarholt, Thomas
(2019).
Såpeboblens fysikk.
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Aarholt, Thomas
(2019).
Å se atomer.
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Haug, Kristian; Nguyen, Phuong Dan; Karlsen, Ole Bjørn; Aarholt, Thomas; Bazioti, Kalliopi & Prytz, Øystein
(2019).
Zinc ferrite spinel embedded in ZnO matrix for solar applications.
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Aarholt, Thomas; Frodason, Ymir Kalmann & Prytz, Øystein
(2019).
The impact of local relaxation on defect-complex STEM contrast.
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Hansen, Per-Anders Stensby; Zikmund, Tomas; Yu, Ting; Nitsche Kvalvik, Julie; Aarholt, Thomas & Prytz, Øystein
[Show all 8 contributors for this article]
(2018).
Aromatic-fluoride nanocomposite materials by atomic layer deposition.
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Aarholt, Thomas; Sky, Thomas Neset; Nguyen, Phuong Dan & Prytz, Øystein
(2018).
Low-kV EELS band gapmeasurements on indium monolayer structures in ZnO.
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Aarholt, Thomas & Lobato, Ivan
(2017).
MULTEM Simulation Workshop.
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Aarholt, Thomas
(2017).
Searching for single-defects by GPU-accelerated STEM Simulation.
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Aarholt, Thomas
(2017).
Searching for single-defects by GPU-accelerated STEM simulation.
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Aarholt, Thomas
(2017).
Searching for single-defects by GPU-accelerated STEM simulation.
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Aarholt, Thomas
(2017).
Statistical analysis for noise reduction and phase separation in spectroscopy techniques.
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Aarholt, Thomas
(2017).
Smart Align - an acquisition tool for scanning microscopy.