| 1. |
- Baia, L., et al.
(författare)
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TiO2/WO3/Au nanoarchitectures' photocatalytic activity "from degradation intermediates to catalysts' structural peculiarities" Part II: Aerogel based composites - fine details by spectroscopic means
- 2014
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Ingår i: Applied Catalysis B: Environmental. - : Elsevier BV. - 0926-3373. ; 148, s. 589-600
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Tidskriftsartikel (refereegranskat)abstract
- The "build-up" methodology of a composite photocatalyst is a critical issue regarding the showed photocatalytic performance, including the formation of intermediates. To investigate this issue TiO2/WO3/Au aerogel composites were obtained by sal-gel method and subsequent photoreduction (Au) with UV or visible light. The obtained composites' photocatalytic activity and intermediate formation profiles were evaluated using phenol as a model pollutant. XPS/UPS, XAFS and DRS were used to uncover local coordination, surface chemistry (of the different types of atoms (Ti, W, O and Au) and the band-structure (band-gap, possible electron transitions) of the obtained nanomaterials. The intermediates' evolution profile and structural peculiarities were successfully correlated and it was shown that each minor structural (bulk or surface) change has a significant impact on the photocatalytic activity and intermediate formation dynamics. (c) 2013 Elsevier B.V. All rights reserved.
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| 2. |
- Kecsenovity, E., et al.
(författare)
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Decoration of ultra-long carbon nanotubes with Cu2O nanocrystals: A hybrid platform for enhanced photoelectrochemical CO2 reduction
- 2016
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 4, s. 3139-3147
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Tidskriftsartikel (refereegranskat)abstract
- Photoelectrochemical reduction of CO2 to form useful chemicals is an increasingly studied avenue for harnessing and storing solar energy. In the quest for efficient and stable photocathode materials, nanostructured hybrid assemblies are eminently attractive candidates, because they exhibit multiple favorable properties that cannot be expected from a single material. One possible direction is to combine p-type inorganic semiconductors with highly conductive large surface area electrodes such as carbon nanotube networks. In this work, the controlled synthesis and photoelectrochemical behavior of CNT/Cu2O films was reported for the first time for CO2 reduction applications. A carefully designed, multiple-step electrodeposition protocol was developed that ensured homogeneous coating of CNTs with Cu2O nanocrystals. The hybrid materials were characterized by electron microscopy, X-ray diffraction, Raman spectroscopy, electrochemical impedance spectroscopy, and photoelectrochemical methods. The hybrid films had five-fold higher electrical conductivity compared to their pure Cu2O counterparts. This enhanced charge transport property resulted in a drastic increase in the photocurrents measured for CO2 reduction. In addition to this superior performance, long term photoelectrolysis measurements proved that the CNT/Cu2O hybrids were more stable than the oxide alone. These observations, together with the established structure/property relationships, may contribute to the rational design of nanocarbon/inorganic semiconductor hybrid photocathodes for deployment in photoelectrochemical cells.
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| 3. |
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| 4. |
- Szabó, T., et al.
(författare)
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Charge stabilization by reaction center protein immobilized to carbon nanotubes functionalized by amine groups and poly(3-thiophene acetic acid) conducting polymer
- 2012
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Ingår i: Physica status solidi. B, Basic research. - : Wiley-VCH Verlagsgesellschaft. - 0370-1972 .- 1521-3951. ; 249:12, s. 2386-2389
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Tidskriftsartikel (refereegranskat)abstract
- A large number of studies have indicated recently that photosynthetic reaction center proteins (RC) bind successfully to nanostructures and their functional activity is largely retained. The major goal of current research is to find the most efficient systems and conditions for the photoelectric energy conversion and for the stability of this bio-nanocomposite. In our studies, we immobilized the RC protein on multiwalled carbon nanotubes (MWNT) through specific chemical binding to amine functional groups and through conducting polymer (poly(3-thiophene acetic acid), PTAA). Both structural (TEM, AFM) and functional (absorption change and conductivity) measurements has shown that RCs could be bound effectively to functionalized CNTs. The kinetics of the light induced absorption change indicated that RCs were still active in the composite and there was an interaction between the protein cofactors and the CNTs. The light generated photocurrent was measured in an electrochemical cell with transparent CNT electrode designed specially for this experiment.
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| 5. |
- Szabó, T., et al.
(författare)
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Generating photocurrent by nanocomposites based on photosynthetic reaction centre protein
- 2015
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Ingår i: Physica status solidi. B, Basic research. - : Wiley-VCH Verlagsgesellschaft. - 0370-1972 .- 1521-3951. ; 252:11, s. 2614-2619
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Tidskriftsartikel (refereegranskat)abstract
- An optoelectronic device, which converts light energy to electric potential, was designed and fabricated by using photosynthetic reaction centre (RC) proteins of purple bacterium Rhodobacter sphaeroides R-26, based on the structure and function of the dye sensitised organic solar cells. First, an electrochemical cell with three electrodes was created especially for this measurement. ITO covered by the MWCNT-RC containing sample served as the working electrode and the counter and the reference electrodes were platinum and Ag\AgCl, respectively. Water soluble ubiquinone-0 and ferrocene, in some experiments were used as mediators. In another experiment, the presence of the RCs in the active layer under dried conditions assured tuneable wavelength sensitivity, in general in the visible, but specially, in the near infrared (700-1000 nm) spectral range. The lifetime of the primary charge separation is in the ps time scale and that of the charge stabilisation can be modulated (at least theoretically) between ps and seconds. A successful combination of RC protein with a light energy converter device in spectroelectrochemical cell (wet conditions in buffered electrolyte) and in dried multilayer structure will be presented here.
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