| 1. |
- Alammar, Tarek, et al.
(författare)
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The Power of Ionic Liquids : Crystal Facet Engineering of SrTiO3 Nanoparticles for Tailored Photocatalytic Applications
- 2021
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Sonochemical synthesis of nano-sized SrTiO3 carried out at close to room temperature, in ionic liquids (ILs) allows the tuning of particle size and particle morphology, that is, tracht and habitus, as well as particle aggregation via the choice of the ionic liquids (ILs) as the reaction medium. The nanoparticles demonstrate high performance for photocatalytic water splitting and photodecomposition of organic material. To this end bis(trifluoromethanesulfonyl)amide ([Tf2N](-))-based ILs with cations of different properties with respect to specific interactions with the target material are investigated. Isolated, 15 +/- 1 nm sized nano-spheres of SrTiO3 are observed to form in [C(3)mimOH][Tf2N] ([C(3)mimOH](+) = 1-(3-hydroxypropyl)-3-methylimidazolium). Aggregation of small sized nanoparticles are observed to around 250 +/- 100 nm large cube-like formations in [C(4)mim][Tf2N] ([C(4)mim](+) = 1-butyl-3-methylimidazolium), raspberry-like in [C4Py][Tf2N] ([C4Py](+) butylpyridinium), and ball-like in [P-66614][Tf2N] ([P-66614](+) tetradecyltrihexyl phosphonium). Importantly, the different materials show different performance as photocatalysts. SrTiO3 prepared in [C(4)mim][Tf2N] shows the highest photocatalytic activity for H-2 evolution (1115.4 mu mol h(-1)) when using 0.025 wt% Rh as the co-catalyst, whereas the material prepared in [C(3)mimOH][Tf2N] shows the highest activity for the photocatalytic degradation of methylene blue (88%) under UV irradiation. The different photocatalytic activities can be correlated with the different crystal surface facets expressed in the respective nanosized SrTiO3 material, {110} for material obtained from [C(4)mim][Tf2N], and {100} for material from [C(3)mimOH][Tf2N]. First-principles density functional theory (DFT) calculations are used to support the experimental findings.
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| 2. |
- Attias, Noam, et al.
(författare)
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Biofabrication of Nanocellulose–Mycelium Hybrid Materials
- 2021
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Ingår i: Advanced Sustainable Systems. - : Wiley-VCH Verlag. - 2366-7486. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Healthy material alternatives based on renewable resources and sustainable technologies have the potential to disrupt the environmentally damaging production and consumption practices established throughout the modern industrial era. In this study, a mycelium–nanocellulose biocomposite with hybrid properties is produced by the agitated liquid culture of a white-rot fungus (Trametes ochracea) with nanocellulose (NC) comprised as part of the culture media. Mycelial development proceeds via the formation of pellets, where NC is enriched in the pellets and depleted from the surrounding liquid media. Micrometer-scale NC elements become engulfed in mycelium, whereas it is hypothesized that the nanometer-scale fraction becomes integrated within the hyphal cell wall, such that all NC in the system is essentially surface-modified by mycelium. The NC confers mechanical strength to films processed from the biocomposite, whereas the mycelium screens typical cellulose–water interactions, giving fibrous slurries that dewater faster and films that exhibit significantly improved wet resistance in comparison to pure NC films. The mycelium–nanocellulose biocomposites are processable in the ways familiar to papermaking and are suggested for diverse applications, including packaging, filtration, and hygiene products.
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| 3. |
- Lind, Hans, et al.
(författare)
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Hydrogen Evolution Reaction for Vacancy-Ordered i-MXenes and the Impact of Proton Absorption into the Vacancies
- 2021
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Ingår i: Advanced Sustainable Systems. - : Wiley. - 2366-7486. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- A study of the hydrogen evolution reaction (HER) for Mo-, W-, and Nb-based MXenes is presented, where W1.33C MXene with ordered vacancies is chosen for further investigation. The electrochemical measurements show that if the W1.33C MXene is subjected to high cathodic potentials, it greatly improves the activity and onset potential for the HER. The enhancement continues to improve independent of whether the potential is kept fixed at a certain cathodic potential or if the potential is scanned repeatedly. Interestingly, the improvement disappears if the material is subjected to anodic potential. Based on these observations, the hydrogen interaction with the MXene surface as well as in the vacancies is investigated by means of first-principles calculations. These show that the adsorption energy of hydrogen is sensitive to both surface coverage and vacancy occupancy, and that, for certain structures with hydrogen in the vacancies, thermoneutral values of hydrogen adsorption can be obtained. Based on the calculations it is argued that under high cathodic potentials, protons can transfer to the vacancies and stay there in a metastable state as hydrogen atoms, while at anodic potential the process is reversed. The first-principles results provide a rationale for the strongly enhanced HER activity observed experimentally on W1.33C MXene.
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| 4. |
- Ye, Xinchen, et al.
(författare)
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High-Temperature and Chemically Resistant Foams from Sustainable Nanostructured Protein
- 2021
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Ingår i: Advanced sustainable systems. - : Wiley. - 2366-7486. ; , s. 2100063-
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Tidskriftsartikel (refereegranskat)abstract
- Covalently crosslinked protein networks produced from whey protein nanofibrils (PNFs) are demonstrated to be sustainable high-performance foams that show chemical resistance and mechanical strength, stiffness, and toughness on harsh aging at 150 °C. The aged foams are able to retain their properties at 180 °C for as long as 24 h, far exceeding the properties of most classical petroleum-based thermoplastics. The foams are further developed into soft foams by the addition of glycerol as a plasticizer. The improvement in the mechanical performance of the foams with aging, which is equivalent to an increase by one order of magnitude in modulus and yield strength, is confirmed to be associated with (iso)peptide crosslinks. The results open the way for using protein-based foam materials in severe/corrosive environments such as filtration, thermal insulation, and fluid absorption. The protein foams produced are suggested as suitable alternatives to petroleum-based porous polymers.
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