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Memarian, N., Farahi, E., Tobeiha, N., You, S. & Concina, I. (2024). Understanding Graphitic Carbon Nitride as Photocatalyst: A Case Study on Thermal Engineering of Physical and Chemical Features. Physica Status Solidi (a) applications and materials science, Article ID 2300844.
Öppna denna publikation i ny flik eller fönster >>Understanding Graphitic Carbon Nitride as Photocatalyst: A Case Study on Thermal Engineering of Physical and Chemical Features
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2024 (Engelska)Ingår i: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, artikel-id 2300844Artikel i tidskrift (Refereegranskat) Epub ahead of print
Abstract [en]

Rationalizing material features according to the adopted synthetic strategy, aiming then to tune them on demand, is among the most relevant purposes of investigation in materials science. Herein, the systematic analysis of the dependence of graphitic carbon nitride (g-C3N4) physical characteristics on the decomposition temperature of urea, rationalizing the impact of synthetic temperature on several characteristics of the materials (degree of N–H condensation, carbon vs nitrogen content, structural parameters, photoluminescence lifetime, surface area, pores volume), is discussed. g-C3N4 nanostructures are fabricated by thermal decomposition of urea at different temperatures under ambient atmosphere, obtaining an almost ideal stoichiometry (C/N = 0.72) when setting the temperature at 600 °C. The samples show structural, textural, compositional, and optical differences directly depending on the fabrication temperature: specific surface area, pore volume and size, intralayer distance, and speed of radiative recombination of photogenerated charges are proportionally enhanced by increasing the synthesis temperature. The role played by all the physicochemical features of the prepared samples in promoting the catalytic degradation of Rhodamine B is investigated, highlighting their synergistic role in enhancing the catalytic efficiency. Significant differences in the dye degradation are recorded when using either UV or solar simulated light, demonstrating that Rhodamine B photosensitization rules the process.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2024
Nyckelord
g-C3N4, intralayer distance, photocatalysis, photoluminescence lifetime, urea thermal decomposition
Nationell ämneskategori
Fysikalisk kemi Materialkemi
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-104513 (URN)10.1002/pssa.202300844 (DOI)2-s2.0-85185129668 (Scopus ID)
Anmärkning

Full text license: CC BY-NC-ND

Tillgänglig från: 2024-03-07 Skapad: 2024-03-07 Senast uppdaterad: 2024-03-07
Khasevani, S. G., Nikjoo, D., Chaxel, C., Umeki, K., Sarmad, S., Mikkola, J.-P. & Concina, I. (2023). Empowering Adsorption and Photocatalytic Degradation of Ciprofloxacin on BiOI Composites: A Material-by-Design Investigation. ACS Omega, 8(46), 44044-44056
Öppna denna publikation i ny flik eller fönster >>Empowering Adsorption and Photocatalytic Degradation of Ciprofloxacin on BiOI Composites: A Material-by-Design Investigation
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2023 (Engelska)Ingår i: ACS Omega, E-ISSN 2470-1343, Vol. 8, nr 46, s. 44044-44056Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Binary and ternary composites of BiOI with NH2-MIL-101(Fe) and a functionalized biochar were synthesized through an in situ approach, aimed at spurring the activity of the semiconductor as a photocatalyst for the removal of ciprofloxacin (CIP) from water. Experimental outcomes showed a drastic enhancement of the adsorption and the equilibrium (which increased from 39.31 mg g–1 of bare BiOI to 76.39 mg g–1 of the best ternary composite in 2 h time), while the kinetics of the process was not significantly changed. The photocatalytic performance was also significantly enhanced, and the complete removal of 10 ppm of CIP in 3 h reaction time was recorded under simulated solar light irradiation for the best catalyst of the investigated batch. Catalytic reactions supported by different materials obeyed different reaction orders, indicating the existence of different mechanisms. The use of scavengers for superoxide anion radicals, holes, and hydroxyl radicals showed that although all these species are involved in CIP photodegradation, the latter play the most crucial role, as also confirmed by carrying out the reaction at increasing pH conditions. A clear correlation between the reduction of BiOI crystallite sizes in the composites, as compared to the bare material, and the material performance as both adsorbers and photocatalyst was identified. 

Ort, förlag, år, upplaga, sidor
American Chemical Society (ACS), 2023
Nationell ämneskategori
Fysikalisk kemi Materialkemi
Forskningsämne
Energiteknik; Experimentell fysik; Avfallsteknik
Identifikatorer
urn:nbn:se:ltu:diva-103204 (URN)10.1021/acsomega.3c06243 (DOI)001108005100001 ()2-s2.0-85178352921 (Scopus ID)
Forskningsfinansiär
Kempestiftelserna, SMK-1974Knut och Alice Wallenbergs StiftelseBio4Energy
Anmärkning

Validerad;2023;Nivå 2;2023-12-11 (joosat);

License full text: CC BY

Tillgänglig från: 2023-12-11 Skapad: 2023-12-11 Senast uppdaterad: 2024-03-07Bibliografiskt granskad
Solomon, G., Lecca, M., Bisetto, M., Gilzad Kohan, M., Concina, I., Natile, M. M. & Vomiero, A. (2023). Engineering Cu2O Nanowire Surfaces for Photoelectrochemical Hydrogen Evolution Reaction. ACS Applied Energy Materials, 6(2), 832-840
Öppna denna publikation i ny flik eller fönster >>Engineering Cu2O Nanowire Surfaces for Photoelectrochemical Hydrogen Evolution Reaction
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2023 (Engelska)Ingår i: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 6, nr 2, s. 832-840Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Cu2O is a narrow band gap material serving as an important candidate for photoelectrochemical hydrogen evolution reaction. However, the main challenge that hinders its practical exploitation is its poor photostability, due to its oxidation into CuO by photoexcited holes. Here, we thoroughly minimize the photo-oxidation of Cu2O nanowires by growing a thin layer of the TiO2 protective layer and an amorphous layer of the VOx cocatalyst using magnetron sputtering and atomic layer deposition, respectively. After optimization of the protective and the cocatalyst layers, the photoelectrode exhibits a current density of −2.46 mA/cm2 under simulated sunlight (100 mW/cm2) at 0.3 V versus reversible hydrogen electrode, and its performance is stable for an extended illumination time. The chemical stability and the good performance of the engineered photoelectrode demonstrate the potential of using earth-abundant materials as a light-harvesting device for solar hydrogen production.

Ort, förlag, år, upplaga, sidor
American Chemical Society, 2023
Nyckelord
atomic layer deposition, Cu2O photoelectrode, magnetron deposition, photoelectrochemical hydrogen evolution, water splitting
Nationell ämneskategori
Materialkemi
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-95364 (URN)10.1021/acsaem.2c03122 (DOI)000908364800001 ()2-s2.0-85146159928 (Scopus ID)
Forskningsfinansiär
KempestiftelsernaLuleå tekniska universitetKnut och Alice Wallenbergs Stiftelse
Anmärkning

Validerad;2023;Nivå 2;2023-01-23 (joosat);

Funder: ICMATE-CNR (B93C22000630006); Swedish Foundations

Tillgänglig från: 2023-01-23 Skapad: 2023-01-23 Senast uppdaterad: 2023-01-23Bibliografiskt granskad
Solomon, G., Gilzad Kohan, M., Mazzaro, R., Jugovac, M., Moras, P., Morandi, V., . . . Vomiero, A. (2023). MoS2 Nanosheets Uniformly Anchored on NiMoO4 Nanorods, a Highly Active Hierarchical Nanostructure Catalyst for Oxygen Evolution Reaction and Pseudo-Capacitors. Advanced sustainable systems, 7(2), Article ID 2200410.
Öppna denna publikation i ny flik eller fönster >>MoS2 Nanosheets Uniformly Anchored on NiMoO4 Nanorods, a Highly Active Hierarchical Nanostructure Catalyst for Oxygen Evolution Reaction and Pseudo-Capacitors
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2023 (Engelska)Ingår i: Advanced sustainable systems, E-ISSN 2366-7486, Vol. 7, nr 2, artikel-id 2200410Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Hierarchical nanostructures have attracted considerable research attention due to their applications in the catalysis field. Herein, we design a versatile hierarchical nanostructure composed of NiMoO4 nanorods surrounded by active MoS2 nanosheets on an interconnected nickel foam substrate. The as-prepared nanostructure exhibits excellent oxygen evolution reaction performance, producing a current density of 10 mA cm−2 at an overpotential of 90 mV, in comparison with 220 mV necessary to reach a similar current density for NiMoO4. This behavior originates from the structural/morphological properties of the MoS2 nanosheets, which present numerous surface-active sites and allow good contact with the electrolyte. Besides, the structures can effectively store charges, due to their unique branched network providing accessible active surface area, which facilitates intermediates adsorptions. Particularly, NiMoO4/MoS2 shows a charge capacity of 358 mAhg−1 at a current of 0.5 A g−1 (230 mAhg−1 for NiMoO4), thus suggesting promising applications for charge-storing devices.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2023
Nyckelord
electrocatalysts, hierarchical nanostructures, hydrous catalysts, magnetron sputtering, oxygen evolution reaction, pseudo capacitors, water splitting
Nationell ämneskategori
Energiteknik Materialkemi
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-88421 (URN)10.1002/adsu.202200410 (DOI)000894620200001 ()2-s2.0-85144090100 (Scopus ID)
Forskningsfinansiär
Knut och Alice Wallenbergs StiftelseEU, Horisont 2020, 654002Luleå tekniska universitetKempestiftelserna
Anmärkning

Validerad;2023;Nivå 2;2023-03-03 (hanlid);

Funder: European Commission Graphene Flagship Core3 (881603); EUROFEL-ROADMAP ESFRI;

This article has previously appeared as a manuscript in a thesis.

Tillgänglig från: 2021-12-15 Skapad: 2021-12-15 Senast uppdaterad: 2024-03-27Bibliografiskt granskad
Banari, M., Memarian, N., Concina, I. & Vomiero, A. (2023). UV photodetector study based on Ce: ZnO nanostructures with different concentration of Ce dopant. Optical materials (Amsterdam), 146, Article ID 114576.
Öppna denna publikation i ny flik eller fönster >>UV photodetector study based on Ce: ZnO nanostructures with different concentration of Ce dopant
2023 (Engelska)Ingår i: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 146, artikel-id 114576Artikel i tidskrift (Refereegranskat) Published
Ort, förlag, år, upplaga, sidor
Elsevier, 2023
Nationell ämneskategori
Annan fysik
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-102656 (URN)10.1016/j.optmat.2023.114576 (DOI)
Anmärkning

Validerad;2023;Nivå 2;2023-11-22 (joosat);

Tillgänglig från: 2023-11-22 Skapad: 2023-11-22 Senast uppdaterad: 2023-11-22Bibliografiskt granskad
Gilzad Kohan, M., Dobryden, I., Forchheimer, D., Concina, I. & Vomiero, A. (2022). In-depth photocarrier dynamics in a barrier variable iron-oxide and vertically aligned reduced-graphene oxide composite. NPJ 2D MATERIALS AND APPLICATIONS, 6(1), Article ID 57.
Öppna denna publikation i ny flik eller fönster >>In-depth photocarrier dynamics in a barrier variable iron-oxide and vertically aligned reduced-graphene oxide composite
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2022 (Engelska)Ingår i: NPJ 2D MATERIALS AND APPLICATIONS, E-ISSN 2397-7132, Vol. 6, nr 1, artikel-id 57Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A key requirement for semiconductors operating in light-harvesting devices, is to efficiently convert the absorbed photons to electronic excitations while accommodating low loss pathways for the photogenerated carrier’s transport. The quality of this process corresponds to different relaxation phenomena, yet primarily it corresponds to minimized thermalization of photoexcited carriers and maximum transfer of electron-hole pairs in the bulk of semiconductor. However, several semiconductors, while providing a suitable platform for light-harvesting applications, pose intrinsic low carrier diffusion length of photoexcited carriers. Here we report a system based on a vertical network of reduced graphene oxide (rGO) embedded in a thin-film structure of iron oxide semiconductor, intended to exploit fast electron transport in rGO to increase the photoexcited carrier transfer from the bulk of the semiconductor to rGO and then to the external circuit. Using intermodulation conductive force microscopy, we locally monitored the fluctuation of current output, which is the prime indication of successful charge transfer from photoexcited semiconductor to rGO and efficient charge collection from the bulk of the semiconductor. We reveal the fundamental properties of vertical rGO and semiconductor junction in light-harvesting systems that enable the design of new promising materials for broad-band optical applications.

Ort, förlag, år, upplaga, sidor
Springer Nature, 2022
Nationell ämneskategori
Fysikalisk kemi
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-93220 (URN)10.1038/s41699-022-00333-5 (DOI)000849458700001 ()2-s2.0-85137588426 (Scopus ID)
Forskningsfinansiär
Luleå tekniska universitetKempestiftelsernaEU, Horisont 2020, 65400Knut och Alice Wallenbergs StiftelseVinnova
Anmärkning

Validerad;2022;Nivå 2;2022-09-27 (joosat);

Funder: Swedish Foundations Consolidator Fellowship

Tillgänglig från: 2022-09-27 Skapad: 2022-09-27 Senast uppdaterad: 2022-09-27Bibliografiskt granskad
Khasevani, S. G., Nikjoo, D., Ojwang, D. O., Nodari, L., Sarmad, S., Mikkola, J.-P., . . . Concina, I. (2022). The beauty of being complex: Prussian blue analogues as selective catalysts and photocatalysts in the degradation of ciprofloxacin. Journal of Catalysis, 410, 307-319
Öppna denna publikation i ny flik eller fönster >>The beauty of being complex: Prussian blue analogues as selective catalysts and photocatalysts in the degradation of ciprofloxacin
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2022 (Engelska)Ingår i: Journal of Catalysis, ISSN 0021-9517, E-ISSN 1090-2694, Vol. 410, s. 307-319Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

We investigate the performance of four Prussian blue analogues (PBAs) as catalysts for the selective degradation of ciprofloxacin in water, under both dark and illumination conditions. We show that no light is actually needed to induce a selective degradation of the molecular target, while light irradiation spurs the process, without, however, resulting in the commonly reported photolysis-supported breaking down. We present a systematic characterization of the PBAs aiming at interpreting the catalytic outcomes in the light of a classic coordination chemistry analysis, empowered by the most recent findings in literature. We show that varying the transition metal binding the N atom of the cyanide bridge is key to promote photoinduced charge generation and transfer, which effectively disrupts the molecular target. The analysis of the materials before and after the irradiation with solar simulated light results in a change of the lattice parameters, indicating the possibility of a light-induced spin cross-over.

Ort, förlag, år, upplaga, sidor
Elsevier, 2022
Nyckelord
Prussian blue analogues, Ciprofloxacin degradation, Photocatalysis, Auto-catalytic reactions, Mössbauer spectroscopy
Nationell ämneskategori
Materialkemi Fysikalisk kemi
Forskningsämne
Materialteknik; Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-90488 (URN)10.1016/j.jcat.2022.04.029 (DOI)000799277700002 ()2-s2.0-85129740965 (Scopus ID)
Forskningsfinansiär
Kempestiftelserna, (SMK-1947)ÅForsk (Ångpanneföreningens Forskningsstiftelse), (18-459)Energimyndigheten, (45517-1)
Anmärkning

Validerad;2022;Nivå 2;2022-05-11 (sofila)

Tillgänglig från: 2022-05-02 Skapad: 2022-05-02 Senast uppdaterad: 2022-06-20Bibliografiskt granskad
Solomon, G., Landström, A., Rotta Loria, S., Bolli, E., Mezzetti, A., Facibeni, A., . . . Concina, I. (2022). Tunable physics through coordination chemistry: formation on oxide surface of Ti and Al chelates with 3-hydroxyflavone capable of electron injection and light emission. Dalton Transactions, 51(48), 18489-18501
Öppna denna publikation i ny flik eller fönster >>Tunable physics through coordination chemistry: formation on oxide surface of Ti and Al chelates with 3-hydroxyflavone capable of electron injection and light emission
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2022 (Engelska)Ingår i: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 51, nr 48, s. 18489-18501Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The optoelectronic features of 3-hydroxyflavone (3HF) self-assembled on the surface of an n-type semiconducting metal oxide (TiO2) and an insulator (Al2O3) are herein investigated. 3HF molecules use the coordinatively unsaturated metal ions present on the oxide surface to form metal complexes, which exhibit different behaviors upon light irradiation, depending on the nature of the metal ion. Specifically, we show that the photoluminescence of the surface species can be modulated according to the chemical properties of the complex (i.e. the binding metal ion), resulting in solid-state emitters in a high quantum yield (about 15%). Furthermore, photoinduced charge injection can be promoted or inhibited, providing a multifunctional hybrid system.

Ort, förlag, år, upplaga, sidor
Royal Society of Chemistry, 2022
Nationell ämneskategori
Fysikalisk kemi Materialkemi
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-94377 (URN)10.1039/d2dt02195a (DOI)000890056000001 ()36421057 (PubMedID)2-s2.0-85143358695 (Scopus ID)
Anmärkning

Validerad;2023;Nivå 2;2023-02-10 (joosat);

Licens fulltext: CC BY License

Tillgänglig från: 2022-11-30 Skapad: 2022-11-30 Senast uppdaterad: 2023-02-24Bibliografiskt granskad
Solomon, G., Gilzad Kohan, M., Vagin, M., Rigoni, F., Mazzaro, R., Natile, M. M., . . . Vomiero, A. (2021). Decorating vertically aligned MoS2 nanoflakes with silver nanoparticles for inducing a bifunctional electrocatalyst towards oxygen evolution and oxygen reduction reaction. Nano Energy, 81, Article ID 105664.
Öppna denna publikation i ny flik eller fönster >>Decorating vertically aligned MoS2 nanoflakes with silver nanoparticles for inducing a bifunctional electrocatalyst towards oxygen evolution and oxygen reduction reaction
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2021 (Engelska)Ingår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 81, artikel-id 105664Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Catalysts capable of improving the performance of oxygen evolution reaction (OER) and oxygen reduction reactions (ORR) are essential for the advancement of renewable energy technologies. Herein, Ag-decorated vertically aligned MoS2 nanoflakes are developed via magnetron co-sputtering and investigated as electrocatalyst towards OER and ORR. Due to the presence of silver, the catalyst shows more than 1.5 times an increase in the roughness-normalized rate of OER, featuring a very low Tafel slope (58.6 mv dec−1), thus suggesting that the catalyst surface favors the thermodynamics of hydroxyl radical (OH•) adsorption with the deprotonation steps being the rate-determining steps. The improved performance is attributed to the strong interactions between OOH intermediates and the Ag surface which reduces the activation energy. Rotating ring disk electrode (RRDE) analysis shows that the net disk currents on the Ag-MoS2 sample are two times higher at 0.65 V compared to MoS2, demonstrating the co-catalysis effect of silver doping. Based on the rate constant values, Ag-MoS2 proceeds through a mixed 4 electron and a 2 + 2 serial route reduction mechanism, in which the ionized hydrogen peroxide is formed as a mobile intermediate. The presence of silver decreases the electron transfer number and increases the peroxide yield due to the interplay of a 2 + 2 electron reduction pathway. A 2.5–6 times faster conversion rate of peroxide to OH- observed due to the presence of silver, indicating its effective cocatalyst nature. This strategy can help in designing a highly active bifunctional catalyst that has great potential as a viable alternative to precious-metal-based catalysts.Graphica

Ort, förlag, år, upplaga, sidor
Elsevier, 2021
Nyckelord
Oxygen evolution reaction (OER), Oxygen reduction reaction (ORR), Electrocatalys, tBifunctional catalyst, Magnetron co-sputtering
Nationell ämneskategori
Annan fysik
Forskningsämne
Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-82322 (URN)10.1016/j.nanoen.2020.105664 (DOI)000620327900002 ()2-s2.0-85098781620 (Scopus ID)
Forskningsfinansiär
Vinnova, 2015-01513Knut och Alice Wallenbergs StiftelseEU, Horisont 2020, 654002, 785219KempestiftelsernaLuleå tekniska universitetVetenskapsrådet, 2019-05577
Anmärkning

Validerad;2021;Nivå 2;2021-01-12 (alebob);

Finansiär: MIUR-PON TARANTO (ARS01_00637)

Tillgänglig från: 2021-01-12 Skapad: 2021-01-12 Senast uppdaterad: 2022-01-14Bibliografiskt granskad
Thomas, B., George, G., Landström, A., Concina, I., Geng, S., Vomiero, A., . . . Oksman, K. (2021). Electrochemical Properties of Biobased Carbon Aerogels Decorated with Graphene Dots Synthesized from Biochar. ACS Applied Electronic Materials, 3(11), 4699-4710
Öppna denna publikation i ny flik eller fönster >>Electrochemical Properties of Biobased Carbon Aerogels Decorated with Graphene Dots Synthesized from Biochar
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2021 (Engelska)Ingår i: ACS Applied Electronic Materials, E-ISSN 2637-6113, Vol. 3, nr 11, s. 4699-4710Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Carbon aerogels prepared from low-cost renewable resources are promising electrode materials for future energy storage applications. However, their electrochemical properties must be significantly improved to match the commercially used high-carbon petroleum products. This paper presents a facile method for the green synthesis of carbon aerogels (CAs) from lignocellulosic materials and graphene dots (GDs) from commercially available biochar. The produced carbon aerogels exhibited a hierarchical porous structure, which facilitates energy storage by forming an electrical double-layer capacitance. Surprisingly, the electrochemical analyses of the GD-doped carbon aerogels revealed that in comparison to pristine carbon aerogels, the surface doping of GDs enhanced the electrochemical performance of carbon aerogels, which can be attributed to the combined effect from both double-layer capacitance and pseudocapacitance. Herein, we designed and demonstrated the efficacy of a supercapacitor device using our green carbon electrode as a sustainable option. These green carbon aerogels have opened a window for their practical use in designing sustainable energy storage devices. 

Ort, förlag, år, upplaga, sidor
American Chemical Society (ACS), 2021
Nyckelord
graphene dots, cellulose nanofibers, kraft lignin, carbon aerogels, electrochemical properties
Nationell ämneskategori
Materialkemi
Forskningsämne
Trä och bionanokompositer; Experimentell fysik
Identifikatorer
urn:nbn:se:ltu:diva-87706 (URN)10.1021/acsaelm.1c00487 (DOI)000756989100004 ()2-s2.0-85118673944 (Scopus ID)
Anmärkning

Validerad;2021;Nivå 2;2021-11-30 (johcin)

Tillgänglig från: 2021-11-01 Skapad: 2021-11-01 Senast uppdaterad: 2023-09-05Bibliografiskt granskad
Organisationer
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0003-1785-7177

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