| 1. |
- Buvailo, Halyna I., et al.
(författare)
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Copper-containing hybrid compounds based on extremely rare [V2Mo6O26]6- POM as water oxidation catalysts
- 2019
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Ingår i: Inorganic Chemistry Frontiers. - : Royal Society of Chemistry (RSC). - 2052-1545 .- 2052-1553. ; 6:7, s. 1813-1823
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report two approaches to the synthesis of heterometallic complexes (NH4)(2n)(H(2)en)(n){[Cu(en)(2)][alpha-V2Mo6O26]}center dot 4nH(2)O (1), (NH4)(2){[Cu(dien)(H2O)](2)[alpha-V2Mo6O26]}center dot 5H(2)O (2) and (NH4)(2){[Cu(dien)(H2O)](2)[alpha-V2Mo6O26]}center dot 8H(2)O (3) that have been employed in homogeneous photochemical oxidation of water to dioxygen. In these hybrid metalorganic-inorganic compounds, copper-containing complex fragments are covalently bound to the rare vanadium-disubstituted alpha-octamolybdate cluster. They exhibit variable catalytic activity controlled by the local coordination environment of copper reaching a notably high turnover frequency of 0.24 s(-1) for 3 in combination with a relatively low water oxidation overpotential. The complexes have been also used as precursors for the preparation of mixed oxide phases that have proven to be active heterogeneous water oxidation catalysts.
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| 2. |
- Buvailo, Halyna I., et al.
(författare)
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Hybrid compound based on diethylenetriaminecopper(ii) cations and scarce V-monosubstituted β-octamolybdate as water oxidation catalyst
- 2021
-
Ingår i: RSC Advances. - Cambridge : Royal Society of Chemistry. - 2046-2069. ; 11:51, s. 32119-32125
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report on a new hybrid compound (NH4){[Cu(dien)(H2O)2]2[β-VMo7O26]}·1.5H2O (1), where dien = diethylenetriamine, containing an extremely rare mixed-metal pseudo-octamolybdate cluster. An ex situ EPR spectroscopy provided insights into the formation of paramagnetic species in reaction mixture and in solution of 1. The magneto-structural correlations revealed weak antiferromagnetic exchange interactions between the [Cu(dien)]2+ cations transmitted by intermolecular pathways. The cyclic voltammetry showed the one-electron process associated with the Cu3+/Cu2+ oxidation followed by the multi-electron catalytic wave due to water oxidation with a faradaic yield of 86%. The title compound was thus employed in homogeneous water oxidation catalysis using tris(bipyridine)ruthenium photosensitizer. At pH 8.0, efficiency of the catalytic system attained 0.19 turnovers per second supported by the relatively mild water oxidation overpotential of 0.54 V.
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| 3. |
- Terebilenko, Kateryna V., et al.
(författare)
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Structural transformation of Bi1-x/3V1-xMoxO4 solid solutions for light-driven water oxidationt
- 2016
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Ingår i: Dalton Transactions. - : Royal Society of Chemistry (RSC). - 1477-9226 .- 1477-9234. ; 45:9, s. 3895-3904
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Tidskriftsartikel (refereegranskat)abstract
- The influence of molybdenum content in the solid solutions of Bi1-x/V-3(1-x),MoxO4 (x = 0.05-0.20) on the morphology, band gap, structure and light -driven water oxidation properties has been studied by scanning electron microscopy, X-ray powder diffraction and vibrational spectroscopy (Raman and infrared). To find out the peculiarities of structural changes for bismuth scheelite-related oxides containing both vanadium and molybdenum crystals of Bi0.98V0.93M0.07O4 have been grown from a K-Bi V-Mo-high-temperature melt and characterized by single crystal X-ray diffraction. For the scheelite-related framework both V and Mo were found to occupy the same positions lowering the point group symmetry of tetrahedra from 4/m to 2/m giving monoclinic distortion for solid solutions with x = 0.05----0.10. The most promising photocatalytic performance was obtained for Bi0.96Mo0.1V0.5004, in which the oxygen evolution could reach 21 mu M in 50 s under visible light of LEDs, lambda = 470 +/- 10 nm, and 820.E cm(-2) s(-1). The changes in catalytic properties are shown to be governed by a crystal structure strain with a maximum obtained for the boundary sample between the monoclinic and tetragonal phase.
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| 4. |
- Pavliuk, Mariia V., et al.
(författare)
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Magnetic Manipulation of Spontaneous Emission from Inorganic CsPbBr3 Perovskites Nanocrystals
- 2016
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Ingår i: ADVANCED OPTICAL MATERIALS. - : Wiley. - 2195-1071. ; 4:12, s. 2004-2008
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Tidskriftsartikel (refereegranskat)abstract
- Metal halide perovskites have shown great potential for both light-absorbing and light-emitting devices. It is demonstrated that the presence of a low-magnetic field decreases dramatically the photoluminescence of CsPbBr3. This is found to be due to a decrease in charge separated state lifetime. The effect is fully reversible, and can be exploited for simple and remote modulation of the output of light-emitting devices.
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| 5. |
- Pavliuk, Mariia V., et al.
(författare)
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Structural, magnetic, thermal and visible light-driven water oxidation studies of heterometallic Mn/V complexes
- 2015
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Ingår i: Polyhedron. - : Elsevier BV. - 0277-5387 .- 1873-3719. ; 88, s. 81-89
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Tidskriftsartikel (refereegranskat)abstract
- In this paper a novel synthetic route, being a paradigm of the "direct synthesis" approach, is proposed for the preparation of heterometallic Mn/V compounds by a one-pot reaction. Two synthesized complexes, (NH4)(2)[Mn-2(HGly)(H2O)(10)][V10O28]center dot(HGlY)center dot 2H(2)O (1) and (NR4)(2)[Mn(beta-HAIa)(H2O)(5)](2)[V10O28]center dot 2H(2)O (2) (HGly = glycine, beta-HAla = beta-alanine) have been fully characterized by elemental analysis, single-crystal X-ray diffraction, cyclic voltammetry, magnetic susceptibility, FTIR and EPR spectroscopy. Thermal degradation of these compounds lead to the formation of porous, solid mixed oxides V2O5/MnV2O6 in a ratio of 3:2, which were analyzed by X-ray phase analysis and scanning electron microscopy with energy dispersive X-ray microanalysis (SEM/EDX). Additionally the ability of 1 and 2 to act as oxygen evolving water oxidation catalysts under visible light-driven conditions have been studied in a Clark type cell and by ex situ EPR spectroscopy.
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| 6. |
- Amaro-Gahete, Juan, et al.
(författare)
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Catalytic systems mimicking the [FeFe]-hydrogenase active site for visible-light-driven hydrogen production
- 2021
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Ingår i: Coordination chemistry reviews. - : Elsevier. - 0010-8545 .- 1873-3840. ; 448
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Forskningsöversikt (refereegranskat)abstract
- A global hydrogen economy could ensure environmentally sustainable, safe and cost-efficient renewable energy for the 21st century. Solar hydrogen production through artificial photosynthesis is a key strategy, and the activity of natural hydrogenase metalloenzymes an inspiration for the design of synthetic catalyst systems. [FeFe]-hydrogenase enzymes, present in anaerobic bacteria and green algae, are the most efficient class of biological catalysts for hydrogen evolution. The enzymes operate in an aqueous environment, utilizing electrons that ultimately stem from photosynthesis as the only energy source. Functional synthetic models of the [FeFe]-hydrogenase enzyme active site have garnered intense interest as potential catalysts for the reduction of protons to molecular hydrogen. Herein, we take an extensive journey through the field of biomimetic hydrogenase chemistry for lightdriven hydrogen production. We open with a brief presentation of the structure and redox mechanism of the natural enzyme. Synthetic methodologies, structural characteristics, and hydrogen generation metrics relevant to the synthetic diiron catalysts ([2Fe2S]) are discussed. We first examine multicomponent photocatalysis systems with the [2Fe2S] cluster, followed by photosensitizer-[2Fe2S] dyads and molecular triads. Finally, strategies for the incorporation of [2Fe2S] complexes into supramolecular assemblies, semiconductor supports, and hybrid heterogeneous platforms are laid out. We analyze the individual properties, scope, and limitations of the components present in the photocatalytic reactions. This review illuminates the most useful aspects to rationally design a wide variety of biomimetic catalysts inspired by the diiron subsite of [FeFe]-hydrogenases, and establishes design features shared by the most stable and efficient hydrogen producing photosystems. (C) 2021 The Author(s). Published by Elsevier B.V.
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| 7. |
- Amaro-Gahete, Juan, et al.
(författare)
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Hydroxyl-Decorated Diiron Complex as a [FeFe]-Hydrogenase Active Site Model Complex : Light-Driven Photocatalytic Activity and Heterogenization on Ethylene-Bridged Periodic Mesoporous Organosilica
- 2022
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Ingår i: Catalysts. - : MDPI. - 2073-4344. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- A biomimetic model complex of the [FeFe]-hydrogenase active site (FeFeOH) with an ethylene bridge and a pendant hydroxyl group has been synthesized, characterized and evaluated as catalyst for the light-driven hydrogen production. The interaction of the hydroxyl group present in the complex with 3-isocyanopropyltriethoxysilane provided a carbamate triethoxysilane bearing a diiron dithiolate complex (NCOFeFe), thus becoming a potentially promising candidate for anchoring on heterogeneous supports. As a proof of concept, the NCOFeFe precursor was anchored by a grafting procedure into a periodic mesoporous organosilica with ethane bridges (EthanePMO@NCOFeFe). Both molecular and heterogenized complexes were tested as catalysts for light-driven hydrogen generation in aqueous solutions. The photocatalytic conditions were optimized for the homogenous complex by varying the reaction time, pH, amount of the catalyst or photosensitizer, photon flux, and the type of light source (light-emitting diode (LED) and Xe lamp). It was shown that the molecular FeFeOH diiron complex achieved a decent turnover number (TON) of 70 after 6 h, while NCOFeFe and EthanePMO@NCOFeFe had slightly lower activities showing TONs of 37 and 5 at 6 h, respectively.
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| 8. |
- Buvailo, Halyna, et al.
(författare)
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Facile one-pot synthesis of hybrid compounds based on decavanadate showing water oxidation activity
- 2020
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Ingår i: Inorganic Chemistry Communications. - : Elsevier BV. - 1387-7003 .- 1879-0259. ; 119
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report the synthesis of two hybrid compounds based on decavanadate anion, namely, [Cu(dien)(Hdien)]2[V10O28]·2H2O (1) and (H3dien)2[V10O28]·4H2O (2), where dien = diethylenetriamine, obtained under mild conditions. Both compounds were characterized by elemental, TG/DTA, single crystal and powder X-ray diffraction analyses, IR and EPR spectroscopies. The compound 1 was found to be active as homogeneous photochemical oxidation catalyst of water to dioxygen.
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| 9. |
- Cai, Bin, et al.
(författare)
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Organic Polymer Dots Photocatalyst for CO2 Reduction in Aqueous Solution
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Developing low-cost and efficient photocatalysts to convert CO2 into valuable fuels is desirable to realize a carbon-neutral society. In this work, we report that polymer dots (Pdots) of poly[(9,9′-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-thiadiazole)] (PFBT) without adding any extra co-catalyst can photocatalytic reduction of CO2 into CO in aqueous solution, rendering a CO production rate of 57 μmol g-1 h-1 with a detectable selectivity of up to 100%. 5 cycles of CO2 re-purging experiments show no distinct decline in CO amount and reaction rate, indicating the promising photocatalytic stability of PFBT Pdots in photocatalytic CO2 reduction reaction. Mechanistic study reveals that photo-excited PFBT Pdots are reduced by TEOA first, then the reduced PFBT Pdots can bind CO2 and reduce it into CO via their intrinsic active sites. This work highlights the application of organic Pdots for CO2 reduction in the aqueous solution, which therefore provides a strategy to develop highly efficient and environmental-friendly nanoparticular photocatalysts for CO2 reduction.
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| 10. |
- Cai, Bin, et al.
(författare)
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Organic Polymer Dots Photocatalyze CO2 Reduction in Aqueous Solution
- 2023
-
Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 62:45
-
Tidskriftsartikel (refereegranskat)abstract
- Developing low-cost and efficient photocatalysts to convert CO2 into valuable fuels is desirable to realize a carbon-neutral society. In this work, we report that polymer dots (Pdots) of poly[(9,9 ' -dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-thiadiazole)] (PFBT), without adding any extra co-catalyst, can photocatalyze reduction of CO2 into CO in aqueous solution, rendering a CO production rate of 57 mu mol g(-1) h(-1 )with a detectable selectivity of up to 100 %. After 5 cycles of CO2 re-purging experiments, no distinct decline in CO amount and reaction rate was observed, indicating the promising photocatalytic stability of PFBT Pdots in the photocatalytic CO2 reduction reaction. A mechanistic study reveals that photoexcited PFBT Pdots are reduced by sacrificial donor first, then the reduced PFBT Pdots can bind CO(2 )and reduce it into CO via their intrinsic active sites. This work highlights the application of organic Pdots for CO2 reduction in aqueous solution, which therefore provides a strategy to develop highly efficient and environmentally friendly nanoparticulate photocatalysts for CO2 reduction.
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| 11. |
- Cieslak, Anna M., et al.
(författare)
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Ultra long-lived electron-hole separation within water-soluble colloidal ZnO nanocrystals : Prospective Applications For Solar Energy Production
- 2016
-
Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855. ; 30, s. 187-192
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Tidskriftsartikel (refereegranskat)abstract
- Zinc oxide was one of the first semiconductors used in dye-sensitized solar cells but its instability in aqueous media precludes its use for large-scale applications. Herein, we report on a novel ZnO nanocrystal material derived by an organometallic approach that is simultaneously stable and soluble in water due to its carboxylate oligoethylene glycol shell strongly anchored to the inorganic core by the head groups. The resulting unique inorganic core-organic shell interface also stabilizes the photo-generated hole, leading to a dramatic slowing down of charge recombination, which otherwise is a major hurdle in using nanostructured ZnO.
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| 12. |
- Czapla-Masztafiak, Joanna, et al.
(författare)
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Direct Determination of Metal Complexes' Interaction with DNA by Atomic Telemetry and Multiscale Molecular Dynamics
- 2017
-
Ingår i: The Journal of Physical Chemistry Letters. - : AMER CHEMICAL SOC. - 1948-7185. ; 8:4, s. 805-811
-
Tidskriftsartikel (refereegranskat)abstract
- The lack of molecular mechanistic understanding of the interaction between metal complexes and biomolecules hampers their potential medical use. Herein we present a robust procedure combining resonant X-ray emission spectroscopy and multiscale molecular dynamics simulations, which allows for straightforward elucidation of the precise interaction mechanism at the atomic level. The report unveils an unforeseen hydrolysis process and DNA binding of [Pt{N(p-HC6F4)CH2}(2)py(2)] (Pt103), which showed potential cytotoxic activity in the past. Pt103 preferentially coordinates to adjacent adenine sites, instead of guanine sites as in cisplatin, because of its hydrogen bond ability. Comparison with previous research on cisplatin suggests that selective binding to guanine or adenine may be achieved by controlling the acidity of the compound.
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| 13. |
- Fernandes, Arthur B., et al.
(författare)
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Recoverable and Reusable Polymer Microbead-Supported Metal Nanocatalysts for Redox Chemical Transformations
- 2020
-
Ingår i: ACS APPLIED NANO MATERIALS. - : AMER CHEMICAL SOC. - 2574-0970. ; 3:2, s. 1722-1730
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Tidskriftsartikel (refereegranskat)abstract
- Metal nanoparticles have been widely exploited in catalysis, but their full impact on the environment and human health is still under debate. Here we describe the one-step fabrication of recoverable and reusable polymer microbead-supported metal and metal oxide nanocatalysts for application in batch reactions and flow systems. Au, Ag, and Fe3O4 nanoparticles were prepared directly at the surface of commercial benzylamine-coated spherical polymer beads in water by using low-energy microwave radiation for 5 min. The functionalization of microbead surface with betalamic acid, an antioxidant from plant origin, before irradiation changes the morphology and catalytic properties of the grafted nanoparticles. No leaching of the active phase was observed during the application of these effective and ready-to-use nanocatalysts on the reduction of 4-nitrophenol and oxidation of dihydrorhodamine 123. The supported nanocatalysts were recovered by filtration and/or magnetic separation and reused up to three times without significant drop in catalytic performance. These results can stimulate the controlled and facile synthesis of recoverable microbead-supported magnetic and nonmagnetic nanocatalysts that can be applied under myriad reaction conditions and reused multiple times.
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| 14. |
- Fernandes, Daniel L. A., et al.
(författare)
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Green microfluidic synthesis of monodisperse silver nanoparticles via genetic algorithm optimization
- 2016
-
Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 6:98, s. 95693-95697
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Tidskriftsartikel (refereegranskat)abstract
- A scalable and green procedure for the microfluidic flow synthesis of monodisperse silver nanoparticles is reported. Beetroot extract is used both as a reducing and growth-regulating agent. A multi-objective genetic algorithm was used to automate the optimization of the reaction and reduce sample polydispersity observed in previous reports. The proposed methodology ensures high-quality nanoparticles in a rapidly manner and devoid of human skill or intuition, essential for method standardization and implementation.
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| 15. |
- Fernandes, Daniel L. A., et al.
(författare)
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Novel photo-reactor for fast screening of photo-catalytic systems
- 2017
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Ingår i: Journal of Photochemistry and Photobiology A. - : Elsevier BV. - 1010-6030 .- 1873-2666. ; 335, s. 36-39
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Tidskriftsartikel (refereegranskat)abstract
- Photo-catalysis is an emerging technology for clean energy production, organic synthesis and environmental protection, etc. While there is a hydrogen of systems and schemes to attain these objectives, there is a paucity of photo-reactors capable of determine catalytic abilities in real time with reduce amounts of samples, i.e., fast-screening of catalyst and reaction parameters. Herein, we report a novel photo-reactor for simultaneous online monitoring of gaseous products with quadrupole mass spectrometry and photo-physics with fibre optic UV/Vis with millisecond time resolution on 4 mL cuvettes.
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| 16. |
- Garlisi, Corrado, et al.
(författare)
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N-TiO2/Cu-TiO2 double-layer films : Impact of stacking order on photocatalytic properties
- 2017
-
Ingår i: Journal of Catalysis. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0021-9517 .- 1090-2694. ; 353, s. 116-122
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report for the first time a unique configuration of N-doped and Cu-doped TiO2 bilayer. The activity of TiO2 was improved by combining Cu- and N-doping in a layered thin-film structure. The impact of the stacking order was studied, pointing out how the best arrangement is by far the one with Cu-TiO2 as the top layer. The results reveal a unique and simple way to enhance the photocatalytic response of TiO2 in the visible domain.
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| 17. |
- Hattori, Yocefu, et al.
(författare)
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Light-induced ultrafast proton-coupled electron transfer responsible for H-2 evolution on silver plasmonics
- 2018
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Ingår i: Materials Today. - : ELSEVIER SCI LTD. - 1369-7021 .- 1873-4103. ; 21:6, s. 590-593
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Tidskriftsartikel (refereegranskat)abstract
- Light-driven proton-coupled electron transfer (PCET) reactions on nanoplasmonics would bring temporal control of their reactive pathways, in particular, prolong their charge separation state. Using a silver nano-hybrid plasmonic structure, we observed that optical excitation of Ag-localized surface plasmon instigated electron injection into TiO2 conduction band and oxidation of isopropanol alcoholic functionality. Femtosecond transient infrared absorption studies show that electron transfer from Ag to TiO2 occurs in ca. 650 fs, while IPA molecules near the Ag surface undergo an ultrafast bidirectional PCET step within 400 fs. Our work demonstrates that ultrafast PCET reaction plays a determinant role in prolonging charge separation state, providing an innovative strategy for visible-light photocatalysis with plasmonic nanostructures.
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| 18. |
- Hola, Katerina, et al.
(författare)
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Carbon Dots and [FeFe] Hydrogenase Biohybrid Assemblies for Efficient Light-Driven Hydrogen Evolution
- 2020
-
Ingår i: ACS Catalysis. - : AMER CHEMICAL SOC. - 2155-5435. ; 10:17, s. 9943-9952
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Tidskriftsartikel (refereegranskat)abstract
- Artificial photosynthesis is seen as a path to convert and store solar energy into chemical energy for our society. In this work, highly fluorescent aspartic acid-based carbon dots (CDs) are synthesized and employed as a photosensitizer to drive photocatalytic hydrogen evolution with an [FeFe] hydrogenase (CrHydA1). The direct interaction in CDs from L-aspartic acid (AspCDs)/CrHydA1 self-assembly systems, which is visualized from native gel electrophoresis, has been systematically investigated to understand the electron-transfer dynamics and its impact on photocatalytic efficiency. The study discloses the significant influence of the electrostatic surrounding generated by sacrificial electron donors on the intimate interplay within the oppositely charged subunits of the biohybrid assembly as well as the overall photocatalytic performance. The system reaches an external quantum efficiency of 1.7% at 420 nm and an initial activity of 1.73 mu mol(H-2) mg(-1) (hydrogenase) min(-1) under favorable electrostatic conditions. Owing to the ability of the synthesized AspCDs to operate efficiently under visible light, in contrast to other materials that require UV illumination, the stability of the biohybrid assembly in the presence of a redox mediator extends beyond 1 week.
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| 19. |
- Pavliuk, Mariia V., et al.
(författare)
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Homogeneous Cobalt/Vanadium Complexes as Precursors for Functionalized Mixed Oxides in Visible-Light-Driven Water Oxidation
- 2016
-
Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 9:20, s. 2957-2966
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Tidskriftsartikel (refereegranskat)abstract
- The heterometallic complexes (NH4)2[Co(H2O)6]2[V10O28]·4H2O (1) and (NH4)2[Co(H2O)5(β-HAla)]2[V10O28]·4H2O (2) have been synthesized and used for the preparation of mixed oxides as catalysts for water oxidation. Thermal decomposition of 1 and 2 at relatively low temperatures (<500 °C) leads to the formation of the solid mixed oxides CoV2O6/V2O5 (3) and Co2V2O7/V2O5 (4). The complexes (1, 2) and heterogeneous materials (3, 4) act as catalysts for photoinduced water oxidation. A modification of the thermal decomposition procedure allowed the deposition of mixed metal oxides (MMO) on a mesoporous TiO2 film. The electrodes containing Co/V MMOs in TiO2 films were used for electrocatalytic water oxidation and showed good stability and sustained anodic currents of about 5 mA cm−2 at 1.72 V versus relative hydrogen electrode (RHE). This method of functionalizing TiO2 films with MMOs at relatively low temperatures (<500 °C) can be used to produce other oxides with different functionality for applications in, for example, artificial photosynthesis.
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| 20. |
- Pavliuk, Mariia V., et al.
(författare)
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Hydrated Electron Generation by Excitation of Copper Localized Surface Plasmon Resonance
- 2019
-
Ingår i: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 10:8, s. 1743-1749
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Tidskriftsartikel (refereegranskat)abstract
- Hydrated electrons are important in radiation chemistry and charge transfer reactions, with applications that include chemical damage of DNA, catalysis, and signaling. Conventionally, hydrated electrons are produced by pulsed radiolysis, sonolysis, two-ultraviolet-photon laser excitation of liquid water, or photodetachment of suitable electron donors. Here we report a method for the generation of hydrated electrons via single-visible-photon excitation of localized surface plasmon resonances (LSPRs) of supported sub-3 nm copper nanoparticles in contact with water. Only excitations at the LSPR maximum resulted in the formation of hydrated electrons, suggesting that plasmon excitation plays a crucial role in promoting electron transfer from the nanoparticle into the solution. The reactivity of the hydrated electrons was confirmed via proton reduction and concomitant H-2 evolution in the presence of a Ru/TiO2 catalyst.
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| 21. |
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| 22. |
- Pavliuk, Mariia V., et al.
(författare)
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Hydrogen evolution with CsPbBr3 perovskite nanocrystals under visible light in solution
- 2018
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Ingår i: MATERIALS TODAY COMMUNICATIONS. - : Elsevier BV. - 2352-4928. ; 16, s. 90-96
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Tidskriftsartikel (refereegranskat)abstract
- Direct proton photo-reduction to molecular hydrogen with a lead-halide perovskite photosystem is presented. The concept uses CsPbBr3 nanocrystals and Ru@TiO2 nanoparticles as light harvesters and catalyst, respectively. The photo-system attains charge transfer from donor to acceptor via collision events, established via static and ultrafast spectroscopy. The photo-system exhibits a photon-to-hydrogen efficiency of ca. 0.4%, a respectable efficiency for a system relying on effective collisions for the transference of electrons.
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| 23. |
- Pavliuk, Mariia V., et al.
(författare)
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Hydrogen evolution with nanoengineered ZnO interfaces decorated using a beetroot extract and a hydrogenase mimic
- 2017
-
Ingår i: Sustainable Energy & Fuels. - : Royal Society of Chemistry. - 2398-4902. ; 1, s. 69-73
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report a nano-hybrid photo-system based on abundant elements for H2 production with visible light. The photo-system's proficiency relates to the novel ZnO nanocrystals employed. The ZnO carboxylate oligoethylene glycol shell enhances charge separation and accumulates reactive electrons for the photocatalytic process.
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| 24. |
- Pavliuk, Mariia V., et al.
(författare)
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Nano-hybrid plasmonic photocatalyst for hydrogen production at 20% efficiency
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
-
Tidskriftsartikel (refereegranskat)abstract
- The efficient conversion of light energy into chemical energy is key for sustainable human development. Several photocatalytic systems based on photovoltaic electrolysis have been used to produce hydrogen via water reduction. However, in such devices, light harvesting and proton reduction are carried separately, showing quantum efficiency of about 10–12%. Here, we report a nano-hybrid photocatalytic assembly that enables concomitant reductive hydrogen production and pollutant oxidation with solar-to-fuel efficiencies up to 20%. The modular architecture of this plasmonic material allows the fine-tuning of its photocatalytic properties by simple manipulation of a reduced number of basic components.
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| 25. |
- Pavliuk, Mariia V., et al.
(författare)
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Phenoxazine-based small molecule heterojunction nanoparticles for photocatalytic hydrogen production
- 2023
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Ingår i: Chemical Communications. - : Royal Society of Chemistry. - 1359-7345 .- 1364-548X. ; 59:37, s. 5611-5614
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Tidskriftsartikel (refereegranskat)abstract
- A phenoxazine-based small organic molecular donor POZ-M is designed and synthesized to prepare organic heterojunction nanoparticles (NPs) with a small molecular acceptor ITIC for photocatalytic hydrogen production, giving a reaction rate of up to 63 mmol g−1 h−1. A beneficial molecular design strategy highlights the role of miscibility between POZ-M and ITIC, which is necessary to achieve satisfactory charge separation at the donor/acceptor interface.
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| 26. |
- Pavliuk, Mariia V., et al.
(författare)
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Polymer Dots as Photoactive Membrane Vesicles for [FeFe]-Hydrogenase Self-Assembly and Solar-Driven Hydrogen Evolution
- 2022
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 144:30, s. 13600-13611
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Tidskriftsartikel (refereegranskat)abstract
- A semiartificial photosynthesis approach that utilizes enzymes for solar fuel production relies on efficient photosensitizers that should match the enzyme activity and enable long-term stability. Polymer dots (Pdots) are biocompatible photosensitizers that are stable at pH 7 and have a readily modifiable surface morphology. Therefore, Pdots can be considered potential photosensitizers to drive such enzyme-based systems for solar fuel formation. This work introduces and unveils in detail the interaction within the biohybrid assembly composed of binary Pdots and the HydA1 [FeFe]-hydrogenase from Chlamydomonas reinhardtii. The direct attachment of hydrogenase on the surface of toroid-shaped Pdots was confirmed by agarose gel electrophoresis, cryogenic transmission electron microscopy (Cryo-TEM), and cryogenic electron tomography (Cryo-ET). Ultrafast transient spectroscopic techniques were used to characterize photoinduced excitation and dissociation into charges within Pdots. The study reveals that implementation of a donor–acceptor architecture for heterojunction Pdots leads to efficient subpicosecond charge separation and thus enhances hydrogen evolution (88 460 μmolH2·gH2ase–1·h–1). Adsorption of [FeFe]-hydrogenase onto Pdots resulted in a stable biohybrid assembly, where hydrogen production persisted for days, reaching a TON of 37 500 ± 1290 in the presence of a redox mediator. This work represents an example of a homogeneous biohybrid system combining polymer nanoparticles and an enzyme. Detailed spectroscopic studies provide a mechanistic understanding of light harvesting, charge separation, and transport studied, which is essential for building semiartificial photosynthetic systems with efficiencies beyond natural and artificial systems.
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| 27. |
- Pavliuk, Mariia V., et al.
(författare)
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Preparation, characterization, evaluation and mechanistic study of organic polymer nano-photocatalysts for solar fuel production
- 2022
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Ingår i: Chemical Society Reviews. - : ROYAL SOC CHEMISTRY. - 0306-0012 .- 1460-4744. ; 51:16, s. 6909-6935
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Forskningsöversikt (refereegranskat)abstract
- Production of renewable fuels from solar energy and abundant resourses, such as water and carbon dioxide, via photocatalytic reactions is seen as a promising strategy to adequately address the climate challenge. Photocatalytic systems based on organic polymer nanoparticles (PNPs) are seen as one avenue to transform solar energy into hydrogen and other solar fuels. Semiconducting PNPs are light-harvesting materials with exceptional optical properties, photostability, low cost and low cytotoxity, whose performance surpasses conventional organic dyes and inorganic semiconductors. This review introduces the optimization strategies for the preparation methods of PNP via cocatalyst loading and morphology tuning. We present an analysis on how the preparative methods will impact the physico-chemical properties of these materials, and thus the catalytic activity. A list of experimental techniques is presented for characterization of the physico-chemical properties (optical, morphological, electrochemical and catalytic properties) of PNPs. We provide detailed analysis of PNP photochemistry during photocatalysis with focus on the mechanistic understanding of processes of internal charge generation and transport to the catalyst. This tutorial review provides the reader with the guidelines on current strategies used to optimize PNP performance highlighting the future directions of polymer nano-photocatalysts development.
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| 28. |
- Sá, Jacinto, et al.
(författare)
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Controlling dark catalysis with quasi half-cycle terahertz pulses
- 2017
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Ingår i: Catalysis Science & Technology. - : Royal Society of Chemistry (RSC). - 2044-4753 .- 2044-4761. ; 7:5, s. 1050-1054
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Tidskriftsartikel (refereegranskat)abstract
- This study reports the changes in the platinum electronic structure induced by a strong electric field originated from quasi half-cycle THz pulses, which forces the C-O molecule to dissociate. The changes could be rationalized via a simple analysis of the local density-of-states and easily characterised via high resolution X-ray absorption spectroscopy (HR-XAS). Thus, conferring half-cycle THz pulses the capability of triggering dark catalytic processes required to follow real time catalytic bond rupture or formation, i.e., time-resolved measurements using THz as the pump and HR-XAS as the probe.
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| 29. |
- Senger, Moritz, et al.
(författare)
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Trapping an Oxidized and Protonated Intermediate of the [FeFe]-Hydrogenase Cofactor under Mildly Reducing Conditions
- 2022
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 61:26, s. 10036-10042
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Tidskriftsartikel (refereegranskat)abstract
- The H-cluster is the catalytic cofactor of [FeFe]-hydrogenase, a metalloenzyme that catalyzes the formation of dihydrogen (H-2). The catalytic diiron site of the H-cluster carries two cyanide and three carbon monoxide ligands, making it an excellent target for IR spectroscopy. In previous work, we identified an oxidized and protonated H-cluster species, whose IR signature differs from that of the oxidized resting state (Hox) by a small but distinct shift to higher frequencies. This "blue shift" was explained by a protonation at the [4Fe-4S] subcomplex of the H-cluster. The novel species, denoted HoxH, was preferentially accumulated at low pH and in the presence of the exogenous reductant sodium dithionite (NaDT). When HoxH was reacted with H-2, the hydride state (Hhyd) was formed, a key intermediate of [FeFe]-hydrogenase turnover. A recent publication revisited our protocol for the accumulation of HoxH in wild-type [FeFe]-hydrogenase, concluding that inhibition by NaDT decay products rather than cofactor protonation causes the spectroscopic "blue shift". Here, we demonstrate that HoxH formation does not require the presence of NaDT (or its decay products), but accumulates also with the milder reductants tris(2-carboxyethyl)phosphine, dithiothreitol, or ascorbic acid, in particular at low pH. Our data consistently suggest that HoxH is accumulated when deprotonation of the H-cluster is impaired, thereby preventing the regain of the oxidized resting state Hox in the catalytic cycle.
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| 30. |
- Shylin, Sergii I., et al.
(författare)
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Efficient visible light-driven water oxidation catalysed by an iron(IV) clathrochelate complex
- 2019
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Ingår i: Chemical Communications. - 1359-7345 .- 1364-548X. ; 55:23, s. 3335-3338
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Tidskriftsartikel (refereegranskat)abstract
- A water-stable FeIV clathrochelate complex catalyzes fast and homogeneous photochemical oxidation of water to dioxygen with a turnover frequency of 2.27 s−1 and a maximum turnover number of 365. An FeV intermediate generated under catalytic conditions is trapped and characterised using EPR and Mössbauer spectroscopy.
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| 31. |
- Shylin, Sergii I., et al.
(författare)
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Photoinduced hole transfer from tris(bipyridine)ruthenium dye to a high-valent iron-based water oxidation catalyst
- 2019
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Ingår i: Faraday discussions. - : ROYAL SOC CHEMISTRY. - 1359-6640 .- 1364-5498. ; 215, s. 162-174
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Tidskriftsartikel (refereegranskat)abstract
- An efficient water oxidation system is a prerequisite for developing solar energy conversion devices. Using advanced time-resolved spectroscopy, we study the initial catalytic relevant electron transfer events in the light-driven water oxidation system utilizing [Ru(bpy)(3)](2+) (bpy = 2,2 '-bipyridine) as a light harvester, persulfate as a sacrificial electron acceptor, and a high-valent iron clathrochelate complex as a catalyst. Upon irradiation by visible light, the excited state of the ruthenium dye is quenched by persulfate to afford a [Ru(bpy)(3)](3+)/SO4- pair, showing a cage escape yield up to 75%. This is followed by the subsequent fast hole transfer from [Ru(bpy)(3)](3+) to the Fe-IV catalyst to give the long-lived Fe-V intermediate in aqueous solution. In the presence of excess photosensitizer, this process exhibits pseudo-first order kinetics with respect to the catalyst with a rate constant of 3.2(1) x 10(10) s(-1). Consequently, efficient hole scavenging activity of the high-valent iron complex is proposed to explain its high catalytic performance for water oxidation.
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| 32. |
- Yu, Wen, et al.
(författare)
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Photosynthetic Polymer Dots-Bacteria Biohybrid System Based on Transmembrane Electron Transport for Fixing CO2 into Poly-3-hydroxybutyrate
- 2023
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 15:1, s. 2183-2191
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Tidskriftsartikel (refereegranskat)abstract
- Organic semiconductor–microbial photosynthetic biohybrid systems show great potential in light-driven biosynthesis. In such a system, an organic semiconductor is used to harvest solar energy and generate electrons, which can be further transported to microorganisms with a wide range of metabolic pathways for final biosynthesis. However, the lack of direct electron transport proteins in existing microorganisms hinders the hybrid system of photosynthesis. In this work, we have designed a photosynthetic biohybrid system based on transmembrane electron transport that can effectively deliver the electrons from organic semiconductor across the cell wall to the microbe. Biocompatible organic semiconductor polymer dots (Pdots) are used as photosensitizers to construct a ternary synergistic biochemical factory in collaboration with Ralstonia eutrophaH16 (RH16) and electron shuttle neutral red (NR). Photogenerated electrons from Pdots promote the proportion of nicotinamide adenine dinucleotide phosphate (NADPH) through NR, driving the Calvin cycle of RH16 to convert CO2 into poly-3-hydroxybutyrate (PHB), with a yield of 21.3 ± 3.78 mg/L, almost 3 times higher than that of original RH16. This work provides a concept of an integrated photoactive biological factory based on organic semiconductor polymer dots/bacteria for valuable chemical production only using solar energy as the energy input.
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