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Dey, A., Silveira, V. R., Bericat Vadell, R., Lindblad, A., Lindblad, R., Shtender, V., . . . Sá, J. (2024). Exploiting hot electrons from a plasmon nanohybrid system for the photoelectroreduction of CO2. Communications Chemistry, 7(1), Article ID 59.
Open this publication in new window or tab >>Exploiting hot electrons from a plasmon nanohybrid system for the photoelectroreduction of CO2
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2024 (English)In: Communications Chemistry, E-ISSN 2399-3669, Vol. 7, no 1, article id 59Article in journal (Refereed) Published
Abstract [en]

Plasmonic materials convert light into hot carriers and heat to mediate catalytic transformation. The participation of hot carriers (photocatalysis) remains a subject of vigorous debate, often argued on the basis that carriers have ultrashort lifetime incompatible with drive photochemical processes. This study utilises plasmon hot electrons directly in the photoelectrocatalytic reduction of CO2 to CO via a Ppasmonic nanohybrid. Through the deliberate construction of a plasmonic nanohybrid system comprising NiO/Au/ReI(phen-NH2)(CO)3Cl (phen-NH2 = 1,10-Phenanthrolin-5-amine) that is unstable above 580 K; it was possible to demonstrate hot electrons are the main culprit in CO2 reduction. The engagement of hot electrons in the catalytic process is derived from many approaches that cover the processes in real-time, from ultrafast charge generation and separation to catalysis occurring on the minute scale. Unbiased in situ FTIR spectroscopy confirmed the stepwise reduction of the catalytic system. This, coupled with the low thermal stability of the ReI(phen-NH2)(CO)3Cl complex, explicitly establishes plasmonic hot carriers as the primary contributors to the process. Therefore, mediating catalytic reactions by plasmon hot carriers is feasible and holds promise for further exploration. Plasmonic nanohybrid systems can leverage plasmon’s unique photophysics and capabilities because they expedite the carrier’s lifetime.

Place, publisher, year, edition, pages
Springer Nature, 2024
National Category
Physical Chemistry Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:uu:diva-526189 (URN)10.1038/s42004-024-01149-8 (DOI)001190547400001 ()38509134 (PubMedID)
Funder
Olle Engkvists stiftelse, 210-0007Swedish Research Council, 2019-03597Knut and Alice Wallenberg Foundation, 2019-0071Uppsala UniversityWallenberg Foundations, WISE, LiU-2023-00139
Note

De två första författarna delar förstaförfattarskapet

Available from: 2024-04-05 Created: 2024-04-05 Last updated: 2024-04-05Bibliographically approved
Dey, A., Mendalz, A., Wach, A., Vadell, R. B., Silveira, V., Leidinger, P. M., . . . Sá, J. (2024). Hydrogen evolution with hot electrons on a plasmonic-molecular catalyst hybrid system. Nature Communications, 15, Article ID 445.
Open this publication in new window or tab >>Hydrogen evolution with hot electrons on a plasmonic-molecular catalyst hybrid system
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2024 (English)In: Nature Communications, E-ISSN 2041-1723, Vol. 15, article id 445Article in journal (Refereed) Published
Abstract [en]

Plasmonic systems convert light into electrical charges and heat, mediating catalytic transformations. However, there is ongoing controversy regarding the involvement of hot carriers in the catalytic process. In this study, we demonstrate the direct utilisation of plasmon hot electrons in the hydrogen evolution reaction with visible light. We intentionally assemble a plasmonic nanohybrid system comprising NiO/Au/[Co(1,10-Phenanthrolin-5-amine)2(H2O)2], which is unstable at water thermolysis temperatures. This assembly limits the plasmon thermal contribution while ensuring that hot carriers are the primary contributors to the catalytic process. By combining photoelectrocatalysis with advanced in situ spectroscopies, we can substantiate a reaction mechanism in which plasmon-induced hot electrons play a crucial role. These plasmonic hot electrons are directed into phenanthroline ligands, facilitating the rapid, concerted proton-electron transfer steps essential for hydrogen generation. The catalytic response to light modulation aligns with the distinctive profile of a hot carrier-mediated process, featuring a positive, though non-essential, heat contribution. Direct participation of plasmon-induced hot electrons in the photoelectrocatalytic synthesis of hydrogen. This report solves a long-lasting contentious issue surrounding plasmonic materials on catalytic applications.

Place, publisher, year, edition, pages
Springer Nature, 2024
National Category
Chemical Process Engineering
Identifiers
urn:nbn:se:uu:diva-522503 (URN)10.1038/s41467-024-44752-y (DOI)001141040600006 ()38200016 (PubMedID)
Funder
Olle Engkvists stiftelse, 210-0007Knut and Alice Wallenberg Foundation, 2019-0071Swedish Research Council, 2019-03597
Available from: 2024-02-07 Created: 2024-02-07 Last updated: 2024-02-07Bibliographically approved
Berglund, S., Bassy, C., Kaya, I., Andrén, P. E., Shtender, V., Lasagna, M., . . . Glover, S. (2024). Hydrogen production by a fully de novo enzyme.
Open this publication in new window or tab >>Hydrogen production by a fully de novo enzyme
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2024 (English)Manuscript (preprint) (Other academic)
Abstract [en]

Molecular catalysts based on abundant elements that function in neutral water represent an essential component of sustainable hydrogen production. Artificial hydrogenases based on protein-inorganic hybrids have emerged as an intriguing class of catalysts for this purpose. We have prepared a novel artificial hydrogenase based on cobaloxime bound to a de novo three alpha-helical protein, α3C, via a pyridyl-based unnatural amino acid. The functionalized de novo protein was characterised by UV-visible, CD, and EPR spectroscopy, as well as MALDI spectrometry, which confirmed the presence and ligation of cobaloxime to the protein. The new de novo protein produced hydrogen under electrochemical, photochemical and reductive chemical conditions in neutral water solution. A change in hydrogen evolution capability of the de novo enzyme compared with native cobaloxime was observed, with turnover numbers around 80% of that of cobaloxime, and hydrogen evolution rates of 40% of that of cobaloxime. We discuss these findings in the context of existing literature, how our study contributes important information about the functionality of cobaloxime as hydrogen evolving catalysts in protein environments, and the feasibility of using de novo proteins for developent into artificial metalloenzymes. Small de novo proteins as enzyme scaffolds have the potential to function as upscalable bioinspired catalysts thanks to their efficient atom economy, and the findings presented here show that these types of novel enzymes are a possible product. 

National Category
Other Chemistry Topics
Identifiers
urn:nbn:se:uu:diva-526403 (URN)
Available from: 2024-04-10 Created: 2024-04-10 Last updated: 2024-04-10
Shtender, V., Smetana, V., Crivello, J.-C. -., Kravets, A., Gondek, L., Mudring, A.-V. & Sahlberg, M. (2024). Intermetallics of 4:4:1 and 3:3:1 series in La-(Co,Ni)-M (M = Bi, Pb, Te, Sb, Sn and Ga, Al) systems and their properties. Journal of Alloys and Compounds, 982, Article ID 173767.
Open this publication in new window or tab >>Intermetallics of 4:4:1 and 3:3:1 series in La-(Co,Ni)-M (M = Bi, Pb, Te, Sb, Sn and Ga, Al) systems and their properties
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2024 (English)In: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 982, article id 173767Article in journal (Refereed) Published
Abstract [en]

Two series of isostructural intermetallics have been discovered in our search for new compounds with fused honeycomb motifs, both stable at elevated temperatures (1073 K). They crystallize with orthorhombic unit cells - La4Co4M (M = Sn, Sb, Te, Pb, Bi, SG Pbam, a = 8.247-8.315(2), b = 21.913-22.137(7), c = 4.750-4.664(2) angstrom, V = 850.5-869.5(4) angstrom 3, Z = 4) and La3Ni3M (M = Al, Ga, SG Cmcm, a = 4.1790-4.2395(1), b = 10.4921-10.6426 (6), c = 13.6399-13.7616(8) angstrom, V = 606.72-612.05(7), Z = 3). The crystal structures represent interesting variations of semiregular tilings of corrugated anionic layers and predominantly cationic zigzag motifs. The La4Co4M compounds reveal a complex type of ordering with a high degree of frustration as could be expected for the Kagome ' -related lattices, while magnetic ordering in the La3Ni3M series is less evident. Electronic structure calculations have been performed for multiple compounds within both series revealing metallic character and visible local minima around the Fermi level. The bonding picture is characterized by nearly equal contributions from the anionic and the cationic components.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Intermetallics, crystal structure, electronic structure, magnetic properties
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-526081 (URN)10.1016/j.jallcom.2024.173767 (DOI)001181563000001 ()
Funder
Swedish Research CouncilSwedish Foundation for Strategic Research, EM16-0039
Available from: 2024-04-04 Created: 2024-04-04 Last updated: 2024-04-04Bibliographically approved
Ghorai, S., Vieira, R. M., Shtender, V., Delczeg-Czirjak, E. K., Herper, H. C., Björkman, T., . . . Svedlindh, P. (2023). Giant magnetocaloric effect in the (Mn,Fe)NiSi-system.
Open this publication in new window or tab >>Giant magnetocaloric effect in the (Mn,Fe)NiSi-system
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2023 (English)Manuscript (preprint) (Other academic)
Abstract [en]

The search for energy-efficient and environmentally friendly cooling technologies is a key driver for the development of magnetic refrigeration based on the magnetocaloric effect (MCE). This phenomenon arises from the interplay between magnetic and lattice degrees of freedom that is strong in certain materials, leading to a change in temperature upon application or removal of a magnetic field. Here we report on a new material, Mn1−xFexNiSi0.95Al0.05, with an exceptionally large isothermal entropy at room temperature. By combining experimental and theoretical methods we outline the microscopic mechanism behind the large MCE in this material. It is demonstrated that the competition between the Ni2In-type hexagonal phase and the MnNiSi-type orthorhombic phase, that coexist in this system, combined with the distinctly different magnetic properties of these phases, is a key parameter for the functionality of this material for magnetic cooling.

National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-525213 (URN)10.48550/arXiv.2307.00128 (DOI)
Available from: 2024-03-19 Created: 2024-03-19 Last updated: 2024-03-19
Shtender, V., Smetana, V., Crivello, J.-C., Gondek, L., Przewozznik, J., Mudring, A.-V. & Sahlberg, M. (2023). Honeycomb Constructs in the La-Ni Intermetallics: Controlling Dimensionality via p-Element Substitution. Inorganic Chemistry, 62(37), 14843-14851
Open this publication in new window or tab >>Honeycomb Constructs in the La-Ni Intermetallics: Controlling Dimensionality via p-Element Substitution
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2023 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 62, no 37, p. 14843-14851Article in journal (Refereed) Published
Abstract [en]

The new ternary compounds La15Ni13Bi5 and La9Ni8Sn5 were obtained by arc melting under argon from appropriate amounts of the elements and subsequent annealing at 800 degrees C for 2 weeks. Single-crystal X-ray diffraction reveals that they represent two new structure types: La15Ni13Bi5 crystallizes in the hexagonal space group P62m [hP33, a = 14.995(3), c = 4.3421(10) Å, V = 845.5(4) Å3, Z = 1] and La9Ni8Sn5 in P63/m [hP88, a = 23.870(15), c = 4.433(3) Å, V = 2187(3) Å3, Z = 4]. The crystal structures of both compounds are characterized by hexagonal honeycomb-based motifs formed by Ni and Sn that extend along the c axis. The building motif with its three-blade wind turbine shape is reminiscent of the organic molecule triptycene and is unprecedented in extended solids. First-principles calculations have been performed in order to analyze the electronic structure and provide insight into chemical bonding. They reveal significant electron transfer from La to Ni and the respective p-element, which supports the formation of the polyanionic Ni-p-element network. DFT calculations suggest paramagnetic-like behavior for both compounds, which was confirmed by magnetic measurements.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-514755 (URN)10.1021/acs.inorgchem.3c00502 (DOI)001064319200001 ()37676690 (PubMedID)
Funder
Swedish Research CouncilSwedish Foundation for Strategic Research, EM16-0039
Available from: 2023-10-24 Created: 2023-10-24 Last updated: 2023-10-24Bibliographically approved
Hedlund, D., Rosenqvist Larsen, S., Sahlberg, M., Svedlindh, P. & Shtender, V. (2023). Influence of Mn content on the magnetic properties of the hexagonal Mn (Co,Ge)2 phase. Scripta Materialia, 233, Article ID 115534.
Open this publication in new window or tab >>Influence of Mn content on the magnetic properties of the hexagonal Mn (Co,Ge)2 phase
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2023 (English)In: Scripta Materialia, ISSN 1359-6462, E-ISSN 1872-8456, Vol. 233, article id 115534Article in journal (Refereed) Published
Abstract [en]

Herein, we report on the effect of Mn content on the magnetic properties of the hexagonal Mn(Co,Ge)2 with composition Mn36+xCo49-xGe15.This compound was previously described as Mn2Co3Ge (MgZn2-type structure), but later as Mn(Co,Ge)2 with its own structure type, all samples in this work follow the same superstructure model. Samples were synthesized by induction melting, the crystal structures were evaluated using a combination of X-ray diffraction together with scanning electron microscopy equipped and an energy dispersive X-ray spectroscopy detector. The Curie temperature (TC) is shifted towards lower temperature as the Mn content is increased. On the other hand, the spin reorientation temperature (TSRT) increases and the magnetic moment decreases as the Mn content is increased. The magnetocaloric properties were investigated for the x = 1 alloy, Mn37Co48Ge15. It was found that the isothermal entropy change is 2 J kg−1 K−1 at room temperature for an applied field of 5 T.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Permanent magnets, Intermetallic compound, Synthesis, Magnetocalloric properties, Crystal structure
National Category
Condensed Matter Physics Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-504952 (URN)10.1016/j.scriptamat.2023.115534 (DOI)001001481400001 ()
Funder
Swedish Foundation for Strategic Research, EM16-0039Swedish Research Council, 2019-00207
Available from: 2023-06-19 Created: 2023-06-19 Last updated: 2023-06-19Bibliographically approved
Grilli, D., Smetana, V., Ahmed, S. J., Shtender, V., Pani, M., Manfrinetti, P. & Mudring, A.-V. (2023). Lan(n+1)+xNin(n+5)+ySi(n+1)(n+2)–z: A Symmetric Mirror Homologous Series in the La-Ni-Si System. Inorganic Chemistry, 62(27), 10736-10742
Open this publication in new window or tab >>Lan(n+1)+xNin(n+5)+ySi(n+1)(n+2)–z: A Symmetric Mirror Homologous Series in the La-Ni-Si System
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2023 (English)In: Inorganic Chemistry, ISSN 0020-1669, E-ISSN 1520-510X, Vol. 62, no 27, p. 10736-10742Article in journal (Refereed) Published
Abstract [en]

A homologous series La n(n+1)+x Ni n(n+5)+y Si(n+1)(n+2)-z has beenobserved inthe La-Ni-Si representing a symmetric Ni-rich mirrorto the La(n+1)(n+2)Ni n(n-1)+2Si n(n+1). A series of fourhomologous silicides have been discovered duringsystematic explorations in the central part of the La-Ni-Sisystem at 1000 & DEG;C. All compounds La12.5Ni28.0Si18.3 (n = 3; a = 28.8686(8), c = 4.0737(2) & ANGS;, Z = 3), La22.1Ni39.0Si27.8 (n = 4; a = 20.9340(6), c = 4.1245(2) & ANGS;, Z = 1), La32.9Ni49.8Si39.3 (n = 5; a = 24.946(1), c = 4.1471(5) & ANGS;, Z = 1), and La44.8Ni66.1Si53.4 (n =6; a = 28.995(5), c = 4.158(1) & ANGS;, Z = 1) crystallize in the hexagonal space group P6(3)/m and can be generalizedaccording to La n(n+1)+x Ni n(n+5)+y Si(n+1)(n+2)-z with n = 3-6. Their crystalstructures are based on AlB2-type building blocks, fusedLa-centered Ni6Si6 hexagonal prisms, yieldinglarger oligomeric equilateral domains with the edge size equal to n. The domains extend along the c axisand show checkered ordering of the cationic and anionic parts, whileall their atoms are located on mirror planes. La n(n+1)+x Ni n(n+5)+y Si(n+1)(n+2)-z can beconsidered as a mirror series to the La-rich La(n+1)(n+2)Ni n(n-1)+2Si n(n+1), where an exchange of the formal cationic and anionic sites,i.e., La and Si, occurs. The La-Ni-Si system is thefirst system where two such analogous series have been observed.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
National Category
Inorganic Chemistry
Identifiers
urn:nbn:se:uu:diva-512489 (URN)10.1021/acs.inorgchem.3c01194 (DOI)001018305200001 ()37364160 (PubMedID)
Funder
Swedish Energy Agency, 48699-1
Available from: 2023-09-28 Created: 2023-09-28 Last updated: 2023-09-28Bibliographically approved
Ghorai, S., Cedervall, J., Clulow, R., Huang, S., Ericsson, T., Häggström, L., . . . Svedlindh, P. (2023). Site-specific atomic substitution in a giant magnetocaloric Fe2P-type system. Physical Review B, 107(10), Article ID 104409.
Open this publication in new window or tab >>Site-specific atomic substitution in a giant magnetocaloric Fe2P-type system
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2023 (English)In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 107, no 10, article id 104409Article in journal (Refereed) Published
Abstract [en]

Giant magnetocaloric (GMC) materials constitute a requirement for near room temperature magnetic refrigeration. (Fe,Mn)2(P,Si) is a GMC compound with strong magnetoelastic coupling. The main hindrance towards application of this material is a comparably large temperature hysteresis, which can be reduced by metal site substitution with a nonmagnetic element. However, the (Fe,Mn)2(P,Si) compound has two equally populated metal sites, the tetrahedrally coordinated 3f and the pyramidally coordinated 3g sites. The magnetic and magnetocaloric properties of such compounds are highly sensitive to the site specific occupancy of the magnetic atoms. Here we have attempted to study separately the effect of 3f and 3g site substitution with equal amounts of vanadium. Using formation energy calculations, the site preference of vanadium and its influence on the magnetic phase formation are described. A large difference in the isothermal entropy change (as high as 44\%) with substitution in the 3f and 3g sites is observed. The role of the lattice parameter change with temperature and the strength of the magnetoelastic coupling on the magnetic properties are highlighted.

Place, publisher, year, edition, pages
American Physical Society, 2023
National Category
Condensed Matter Physics Materials Chemistry
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-487262 (URN)10.1103/PhysRevB.107.104409 (DOI)000974419900006 ()
Funder
Swedish Foundation for Strategic Research, EM-16-0039Swedish Research Council, 2019-00645StandUpeSSENCE - An eScience CollaborationSwedish National Infrastructure for Computing (SNIC)
Available from: 2022-10-26 Created: 2022-10-26 Last updated: 2023-05-26Bibliographically approved
Paul-Boncour, V., Beran, P., Hervoches, C. & Shtender, V. (2023). TbMgNi4-xCox-(H,D)2 System. II: Correlation between Structural and Magnetic Properties. ACS Omega, 8(33), 30727-30735
Open this publication in new window or tab >>TbMgNi4-xCox-(H,D)2 System. II: Correlation between Structural and Magnetic Properties
2023 (English)In: ACS Omega, E-ISSN 2470-1343, Vol. 8, no 33, p. 30727-30735Article in journal (Refereed) Published
Abstract [en]

The magnetic properties of TbMgNi4-xCox intermetallic compounds and selected hydrides and deuterides of this system have been studied by various techniques, including magnetic measurements, in situ X-ray and neutron powder diffraction. The intermetallic compounds crystallize in a SnMgCu4-type structure and magnetically order below a Curie temperature (T-C), which increases exponentially with the Co content. This can be due to the ordering of the Co sublattice. On the other hand, the insertion of D or H in TbMgNiCo3 strongly decreases T-C. The X-ray diffraction measurements versus temperature reveal cell volume minima at T-C for the compounds with x = 1-3 without any hints of the structure change. The analysis of the neutron diffraction patterns for the intermetallics with x = 2 and 3 indicates a slightly canted ferrimagnetic structure below T-C. The Tb moments refined at 16 K are 4.1(2) (mu B)/Tb for x = 2, and 6.2(1) mu B/Tb for x = 3, which are smaller than the free ion value (9.5 mu B/Tb). This reduction can be due to the influence of temperature but also reveals the crystal field effect. As Ni and Co occupy statistically the same Wyckoff site, an average Ni/Co moment was refined, leading to 1.7(2) (mu B)/atom for x = 2 and 1.8(1) mu B/atom for x = 3 at 16 K. This moment is slightly canted compared to the Tb moment.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2023
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-511036 (URN)10.1021/acsomega.3c04879 (DOI)001044975700001 ()37636972 (PubMedID)
Available from: 2023-09-06 Created: 2023-09-06 Last updated: 2023-09-06Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0002-8690-9957

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