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Fernandes, Daniel L. A.
Alternative names
Publications (10 of 25) Show all publications
Wang, J., Xu, C., Nilsson, A. M., Fernandes, D. L. A. & Niklasson, G. A. (2019). A novel phase function describing light scattering of layers containing colloidal nanospheres. Nanoscale, 11(15), 7404-7413
Open this publication in new window or tab >>A novel phase function describing light scattering of layers containing colloidal nanospheres
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2019 (English)In: Nanoscale, ISSN 2040-3364, E-ISSN 2040-3372, Vol. 11, no 15, p. 7404-7413Article in journal (Refereed) Published
Abstract [en]

Light scattering from small particles exhibit unique angular scattering distributions, which are strongly dependent on the radius to wavelength ratio as well as the refractive index contrast between the particles and the surrounding medium. As the concentration of the particles increases, multiple scattering becomes important. This complicates the description of the angular scattering patterns, and in many cases one has to resort to empirical phase functions. We have measured the angle dependence of light scattering from a polymer layer containing sub-micron metallic and dielectric particles. The samples exhibited strongly forward and backward peaked scattering patterns, which were fitted to a number of empirical approximative phase functions. We found that a novel two-term Reynolds-McCormick (TTRM) phase function gave the best fit to the experimental data in all cases. The feasibility of the TTRM approach was further validated by good agreement with numerical simulations of Mie single scattering phase functions at various wavelengths and sizes, ranging from the Rayleigh scattering regime to the geometrical optics regime. Hence, the widely adaptable TTRM approach is able to describe angular scattering distributions of different kinds of nanospheres and nanocomposites, both in the single scattering and multiple scattering regimes.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-383188 (URN)10.1039/c9nr01707k (DOI)000465315900034 ()30938744 (PubMedID)
Funder
Swedish Research Council, 2016-03713
Available from: 2019-07-25 Created: 2019-07-25 Last updated: 2019-07-25Bibliographically approved
Pavliuk, M. V., Alvarez, S. G., Hattori, Y., Messing, M. E., Czapla-Masztafiak, J., Szlachetko, J., . . . Sá, J. (2019). Hydrated Electron Generation by Excitation of Copper Localized Surface Plasmon Resonance. Journal of Physical Chemistry Letters, 10(8), 1743-1749
Open this publication in new window or tab >>Hydrated Electron Generation by Excitation of Copper Localized Surface Plasmon Resonance
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2019 (English)In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 10, no 8, p. 1743-1749Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Physical Chemistry Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-383191 (URN)10.1021/acs.jpclett.9b00792 (DOI)000465507700014 ()30920838 (PubMedID)
Funder
Swedish Research CouncilStiftelsen Olle Engkvist Byggmästare
Note

De två första författarna delar förstaförfattarskapet.

Available from: 2019-07-24 Created: 2019-07-24 Last updated: 2019-07-24Bibliographically approved
Wang, J., Xu, C., Nilsson, A. M., Fernandes, D. L. A., Strömberg, M., Wang, J. & Niklasson, G. (2018). General Method for Determining Light Scattering and Absorption of Nanoparticle Composites. Advanced Optical Materials, 6(4), Article ID 1801315.
Open this publication in new window or tab >>General Method for Determining Light Scattering and Absorption of Nanoparticle Composites
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2018 (English)In: Advanced Optical Materials, ISSN 2162-7568, E-ISSN 2195-1071, Vol. 6, no 4, article id 1801315Article in journal (Refereed) Published
Abstract [en]

Scattering and absorption from nanoparticles are of major importance in optical research as well as in a range of applications. The Kubelka–Munk two-flux radiative transfer model gives a simple description of light scattering in nanoparticle composite materials, but inversion of experimental transmittance and reflectance data to obtain backscattering and absorption coefficients remains challenging. Here, a general method for evaluating these parameters from transmittance and reflectance spectra, combined with spectral angle resolved light scattering measurements is developed. The angular dependence is approximatedby an extension of the empirical Reynolds–McCormick phase function, which is fitted to the experimental angle resolved light scattering data. This approach is verified by measurements on three typical nanoparticle/polymer composites containing plasmonic Au, ferromagnetic Fe3O4, and dielectric TiO2 particles. An approximation to the angular scattering pattern is further demonstrated, which can be applied to obtain the optical parameters using only reflectance and transmittance data, in cases where angle-resolved measurements are not available. These results can be extended to a wide range of isotropic, anisotropic, and multiple scattering systems, and will be highly useful in the fields of light scattering coatings/metamaterials, UV-shielding films, displays, absorption/scattering layers in solar cells and biological scatterers.

Place, publisher, year, edition, pages
Wiley-VCH Verlagsgesellschaft, 2018
National Category
Other Physics Topics Condensed Matter Physics
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-370103 (URN)10.1002/adom.201801315 (DOI)000459020300005 ()
Funder
Swedish Research Council, 2016-03713Swedish Research Council Formas, 221-2012-444
Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2019-08-01Bibliographically approved
Hattori, Y., Abdellah, M., Rocha, I., Pavliuk, M. V., Fernandes, D. L. A. & Sá, J. (2018). Light-induced ultrafast proton-coupled electron transfer responsible for H-2 evolution on silver plasmonics. Materials Today, 21(6), 590-593
Open this publication in new window or tab >>Light-induced ultrafast proton-coupled electron transfer responsible for H-2 evolution on silver plasmonics
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2018 (English)In: Materials Today, ISSN 1369-7021, E-ISSN 1873-4103, Vol. 21, no 6, p. 590-593Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
ELSEVIER SCI LTD, 2018
National Category
Physical Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-362849 (URN)10.1016/j.mattod.2018.05.002 (DOI)000441765700016 ()
Funder
Swedish Research Council, 2015-03764Stiftelsen Olle Engkvist Byggmästare, 2016/367
Available from: 2018-10-15 Created: 2018-10-15 Last updated: 2018-10-18Bibliographically approved
Czapla-Masztafiak, J., Kubas, A., Kayser, Y., Fernandes, D. L. A., Kwiatek, W. M., Lipiec, E., . . . Sa, J. (2018). Mechanism of hydrolysis of a platinum(IV) complex discovered by atomic telemetry. Journal of Inorganic Biochemistry, 187, 56-61
Open this publication in new window or tab >>Mechanism of hydrolysis of a platinum(IV) complex discovered by atomic telemetry
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2018 (English)In: Journal of Inorganic Biochemistry, ISSN 0162-0134, E-ISSN 1873-3344, Vol. 187, p. 56-61Article in journal (Refereed) Published
Abstract [en]

Herein we report on the hydrolysis mechanism of [Pt{N(p-HC6F4)CH2}(2)(NC5H5)(2)(OH)(2)], a platinum(IV) complex that exhibits anti-cancer properties. Atomic telemetry, an in situ technique based on electron structure sensitive X-ray spectroscopy, revealed that hydrolysis preceded any reduction of the metal center. The obtained results are complemented with F-19 NMR measurements and theoretical calculations and support the observation that this Pt-II complex does not reduce spontaneously to Ptll in HEPES buffer solution at pH 7.4 and after 24 h incubation. These results are of importance for the design of novel Pt-based coordination complexes as well as understanding their behavior under physiological conditions.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE INC, 2018
Keywords
Atomic telemetry, Hydrolysis mechanism, In situ measurement, Anti-cancer Pt complex
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:uu:diva-362089 (URN)10.1016/j.jinorgbio.2018.07.012 (DOI)000442715000006 ()30055396 (PubMedID)
Available from: 2018-10-03 Created: 2018-10-03 Last updated: 2018-10-03Bibliographically approved
Imani, R., Qiu, Z., Younesi, R., Pazoki, M., Fernandes, D. L. A., Mitev, P. D., . . . Tian, H. (2018). Unravelling in-situ formation of highly active mixed metal oxide CuInO2 nanoparticles during CO2 electroreduction. Nano Energy, 49, 40-50
Open this publication in new window or tab >>Unravelling in-situ formation of highly active mixed metal oxide CuInO2 nanoparticles during CO2 electroreduction
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2018 (English)In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 49, p. 40-50Article in journal (Refereed) Published
Abstract [en]

Technologies and catalysts for converting carbon dioxide (CO2) to immobile products are of high interest to minimize greenhouse effects. Copper(I) is a promising catalytic active state of copper but hampered by the inherent instability in comparison to copper(II) or copper(0). Here, we report a stabilization of the catalytic active state of copper(I) by the formation of a mixed metal oxide CuInO2 nanoparticle during the CO2 electroreduction. Our result shows the incorporation of nanoporous Sn:In2O3 interlayer to Cu2O pre-catalyst system lead to the formation of CuInO2 nanoparticles with remarkably higher activity for CO2 electroreduction at lower overpotential in comparison to the conventional Cu nanoparticles derived from sole Cu2O. Operando Raman spectroelectrochemistry is employed to in-situ monitor the process of nanoparticles formation during the electrocatalytic process. The experimental data are collaborated with DFT calculations to provide insight into the electro-formation of the type of Cu-based mixed metal oxide catalyst during the CO2 electroreduction, where a formation mechanism via copper ion diffusion across the substrate is suggested.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE BV, 2018
Keywords
Cuprous oxide, Copper indium oxide, CO2 electroreduction, Operando Raman spectroelectrochemistry, Density functional theory
National Category
Physical Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-358275 (URN)10.1016/j.nanoen.2018.04.013 (DOI)000434829500006 ()
Funder
Stiftelsen Olle Engkvist ByggmästareGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of TechnologyJ. Gust. Richert stiftelseSwedish National Infrastructure for Computing (SNIC), 2017-1-57Swedish National Infrastructure for Computing (SNIC), 2016-10-23
Available from: 2018-08-30 Created: 2018-08-30 Last updated: 2019-03-29Bibliographically approved
Miles, J., Fernandes, D., Young, A., Bond, C. M., Crane, S. W., Ghafur, O., . . . Greenwood, J. B. (2017). A new technique for probing chirality via photoelectron circular dichroism. Analytica Chimica Acta, 984, 134-139
Open this publication in new window or tab >>A new technique for probing chirality via photoelectron circular dichroism
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2017 (English)In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 984, p. 134-139Article in journal (Refereed) Published
Abstract [en]

We present a proof-of-principle approach for discriminating chiral enantiomers based on the phenomenon of multiphoton photoelectron circular dichroism. A novel stereo detection setup was used to measure the number of photoelectrons emitted from chiral molecules in directions parallel or antiparallel to the propagation of the ionising femtosecond laser pulses. In this study, we show how these asymmetries in the ketones camphor and fenchone depend upon the ellipticity of the laser pulses and the enantiomeric excess of the sample. By using a high repetition rate femtosecond laser, enantiomer excesses with uncertainties at the few-percent level could be measured in close to real-time. As the instrument is compact, and commercial turnkey femtosecond lasers are readily available, the development of a stand-alone chiral analysis instrument for a range of applications is now possible.

Place, publisher, year, edition, pages
Amsterdam: ELSEVIER SCIENCE BV, 2017
Keywords
Chirality, Enantiomer excess, Photoelectron spectroscopy, Time-of-flight mass spectrometry, Femtosecond laser ionization
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:uu:diva-330538 (URN)10.1016/j.aca.2017.06.051 (DOI)000408360600011 ()
Available from: 2017-10-04 Created: 2017-10-04 Last updated: 2017-10-04
Pati, P. B., Damas, G., Tian, L., Fernandes, D. L. A., Zhang, L., Bayrak Pehlivan, I., . . . Tian, H. (2017). An experimental and theoretical study of an efficient polymer nano-photocatalyst for hydrogen evolution. Energy & Environmental Science, 10(6), 1372-1376
Open this publication in new window or tab >>An experimental and theoretical study of an efficient polymer nano-photocatalyst for hydrogen evolution
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2017 (English)In: Energy & Environmental Science, ISSN 1754-5692, E-ISSN 1754-5706, Vol. 10, no 6, p. 1372-1376Article in journal (Refereed) Published
Abstract [en]

In this work, we report a highly efficient organic polymer nano-photocatalyst for light driven proton reduction. The system renders an initial rate of hydrogen evolution up to 50 +/- 0.5 mmol g(-1) h(-1), which is the fastest rate among all other reported organic photocatalysts. We also experimentally and theoretically prove that the nitrogen centre of the benzothiadiazole unit plays a crucial role in the photocatalysis and that the Pdots structure holds a close to ideal geometry to enhance the photocatalysis.

Keywords
CATALYSTS; H-2; SYSTEM; ENVIRONMENTAL SCIENCES; CELLS; CONJUGATED POLYMERS; ENERGY & FUELS; ARTIFICIAL PHOTOSYNTHESIS; WATER; ENGINEERING, CHEMICAL; GENERATION; CHEMISTRY, MULTIDISCIPLINARY; VISIBLE-LIGHT
National Category
Polymer Chemistry Engineering and Technology
Identifiers
urn:nbn:se:uu:diva-332949 (URN)10.1039/c7ee00751e (DOI)000403320300009 ()
Funder
Knut and Alice Wallenberg FoundationSwedish Energy AgencyÅForsk (Ångpanneföreningen's Foundation for Research and Development)Stiftelsen Olle Engkvist ByggmästareStandUp
Available from: 2017-11-02 Created: 2017-11-02 Last updated: 2018-09-06Bibliographically approved
Sá, J., Fernandes, D. L. A., Pavliuk, M. V. & Szlachetko, J. (2017). Controlling dark catalysis with quasi half-cycle terahertz pulses. Catalysis Science & Technology, 7(5), 1050-1054
Open this publication in new window or tab >>Controlling dark catalysis with quasi half-cycle terahertz pulses
2017 (English)In: Catalysis Science & Technology, ISSN 2044-4753, E-ISSN 2044-4761, Vol. 7, no 5, p. 1050-1054Article in journal (Refereed) Published
Abstract [en]

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.

National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-320254 (URN)10.1039/c6cy02651f (DOI)000396137800004 ()
Note

Correction in: CATALYSIS SCIENCE & TECHNOLOGY, Volume: 9, Issue: 2, Pages: 517-517, DOI: 10.1039/c8cy90096e

Available from: 2017-04-19 Created: 2017-04-19 Last updated: 2019-02-25Bibliographically approved
Czapla-Masztafiak, J., Nogueira, J. J., Lipiec, E., Kwiatek, W. M., Wood, B. R., Deacon, G. B., . . . Sá, J. (2017). Direct Determination of Metal Complexes' Interaction with DNA by Atomic Telemetry and Multiscale Molecular Dynamics. Journal of Physical Chemistry Letters, 8(4), 805-811
Open this publication in new window or tab >>Direct Determination of Metal Complexes' Interaction with DNA by Atomic Telemetry and Multiscale Molecular Dynamics
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2017 (English)In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 8, no 4, p. 805-811Article in journal (Refereed) Published
Abstract [en]

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.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2017
National Category
Physical Chemistry Medicinal Chemistry
Identifiers
urn:nbn:se:uu:diva-319563 (URN)10.1021/acs.jpclett.7b00070 (DOI)000394484100016 ()28151686 (PubMedID)
Funder
Australian Research Council, FT120100926
Available from: 2017-04-06 Created: 2017-04-06 Last updated: 2018-01-13Bibliographically approved
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