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Araujo, Carlos Moyses
Alternative names
Publications (10 of 47) Show all publications
Ebadi, M., Marchiori, C., Mindemark, J., Brandell, D. & Araujo, C. M. (2019). Assessing structure and stability of polymer/lithium-metal interfaces from first-principles calculations. Journal of Materials Chemistry A, 7(14), 8394-8404
Open this publication in new window or tab >>Assessing structure and stability of polymer/lithium-metal interfaces from first-principles calculations
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2019 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 14, p. 8394-8404Article in journal (Refereed) Published
Abstract [en]

Solid polymer electrolytes (SPEs) are promising candidates for Li metal battery applications, but the interface between these two categories of materials has so far been studied only to a limited degree. A better understanding of interfacial phenomena, primarily polymer degradation, is essential for improving battery performance. The aim of this study is to get insights into atomistic surface interaction and the early stages of solid electrolyte interphase formation between ionically conductive SPE host polymers and the Li metal electrode. A range of SPE candidates are studied, representative of major host material classes: polyethers, polyalcohols, polyesters, polycarbonates, polyamines and polynitriles. Density functional theory (DFT) calculations are carried out to study the stability and the electronic structure of such polymer/Li interfaces. The adsorption energies indicated a stronger adhesion to Li metal of polymers with ester/carbonate and nitrile functional groups. Together with a higher charge redistribution, a higher reactivity of these polymers is predicted as compared to the other electrolyte hosts. Products such as alkoxides and CO are obtained from the degradation of ester- and carbonate-based polymers by AIMD simulations, in agreement with experimental studies. Analogous to low-molecular-weight organic carbonates, decomposition pathways through C-carbonyl-O-ethereal and C-ethereal-O-ethereal bond cleavage can be assumed, with carbonate-containing fragments being thermodynamically favorable.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-382550 (URN)10.1039/c8ta12147h (DOI)000464414200040 ()
Funder
Swedish Energy Agency, 39036-1Swedish Research Council, 621-2014-5984EU, European Research Council, 771777Carl Tryggers foundation
Available from: 2019-05-10 Created: 2019-05-10 Last updated: 2019-08-05Bibliographically 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
Ebadi, M., Nasser, A., Carboni, M., Younesi, R., Marchiori, C., Brandell, D. & Araujo, C. M. (2019). Insights into the Li-Metal/Organic Carbonate Interfacial Chemistry by Combined First-Principles Theory and X-ray Photoelectron Spectroscopy. The Journal of Physical Chemistry C, 123(1), 347-355
Open this publication in new window or tab >>Insights into the Li-Metal/Organic Carbonate Interfacial Chemistry by Combined First-Principles Theory and X-ray Photoelectron Spectroscopy
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2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 1, p. 347-355Article in journal (Refereed) Published
Abstract [en]

X-ray photoelectron spectroscopy (XPS) is a widely used technique to study surfaces and interfaces. In complex chemical systems, however, interpretation of the XPS results and peak assignments is not straightforward. This is not least true for Li-batteries, where XPS yet remains a standard technique for interface characterization. In this work, a combined density functional theory (DFT) and experimental XPS study is carried out to obtain the C 1s and O 1s core-level binding energies of organic carbonate molecules on the surface of Li metal. Decomposition of organic carbonates is frequently encountered in electrochemical cells employing this electrode, contributing to the build up of a complex solid electrolyte interphase (SEI). The goal in this current study is to identify the XPS fingerprints of the formed compounds, degradation pathways, and thereby the early formation stages of the SEI. The contribution of partial atomic charges on the core-ionized atoms and the electrostatic potential due to the surrounding atoms on the core-level binding energies, which is decisive for interpretation of the XPS spectra, are addressed based on the DFT calculations. The results display strong correlations between these two terms and the binding energies, whereas electrostatic potential is found to be the dominating factor. The organic carbonate molecules, decomposed at the surface of the Li metal, are considered based on two different decomposition pathways. The trends of calculated binding energies for products from ethereal carbon-ethereal oxygen bond cleavage in the organic carbonates are better supported when compared to the experimental XPS results.

Place, publisher, year, edition, pages
AMER CHEMICAL SOC, 2019
National Category
Physical Chemistry Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-375877 (URN)10.1021/acs.jpcc.8b07679 (DOI)000455561100036 ()
Funder
Swedish Energy Agency, 39036-1Swedish Research CouncilStandUpCarl Tryggers foundation
Available from: 2019-02-04 Created: 2019-02-04 Last updated: 2019-08-05Bibliographically approved
Damas, G., Miranda, C., Sgarbi, R., Portela, J., Camilo, M. R. & Araujo, C. M. (2019). On the Mechanism of Carbon Dioxide Reduction on Sn-Based Electrodes: Insights into the Role of Oxide Surfaces. Catalysts, 9(8), Article ID 636.
Open this publication in new window or tab >>On the Mechanism of Carbon Dioxide Reduction on Sn-Based Electrodes: Insights into the Role of Oxide Surfaces
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2019 (English)In: Catalysts, E-ISSN 2073-4344, Vol. 9, no 8, article id 636Article in journal (Refereed) Published
Abstract [en]

The electrochemical reduction of carbon dioxide into carbon monoxide, hydrocarbons and formic acid has offered an interesting alternative for a sustainable energy scenario. In this context, Sn-based electrodes have attracted a great deal of attention because they present low price and toxicity, as well as high faradaic efficiency (FE) for formic acid (or formate) production at relatively low overpotentials. In this work, we investigate the role of tin oxide surfaces on Sn-based electrodes for carbon dioxide reduction into formate by means of experimental and theoretical methods. Cyclic voltammetry measurements of Sn-based electrodes, with different initial degree of oxidation, result in similar onset potentials for the CO2 reduction to formate, ca. −0.8 to −0.9 V vs. reversible hydrogen electrode (RHE), with faradaic efficiencies of about 90–92% at −1.25 V (vs. RHE). These results indicate that under in-situ conditions, the electrode surfaces might converge to very similar structures, with partially reduced or metastable Sn oxides, which serve as active sites for the CO2 reduction. The high faradaic efficiencies of the Sn electrodes brought by the etching/air exposition procedure is ascribed to the formation of a Sn oxide layer with optimized thickness, which is persistent under in situ conditions. Such oxide layer enables the CO2 “activation”, also favoring the electron transfer during the CO2 reduction reaction due to its better electric conductivity. In order to elucidate the reaction mechanism, we have performed density functional theory calculations on different slab models starting from the bulk SnO and Sn6O4(OH)4 compounds with focus on the formation of -OH groups at the water-oxide interface. We have found that the insertion of CO2 into the Sn-OH bond is thermodynamically favorable, leading to the stabilization of the tin-carbonate species, which is subsequently reduced to produce formic acid through a proton-coupled electron transfer process. The calculated potential for CO2 reduction (E = −1.09 V vs. RHE) displays good agreement with the experimental findings and, therefore, support the CO2 insertion onto Sn-oxide as a plausible mechanism for the CO2 reduction in the potential domain where metastable oxides are still present on the Sn surface. These results not only rationalize a number of literature divergent reports but also provide a guideline for the design of efficient CO2 reduction electrocatalysts.

National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-390068 (URN)10.3390/catal9080636 (DOI)
Funder
StandUpSwedish Research CouncilSwedish National Infrastructure for Computing (SNIC)
Available from: 2019-08-05 Created: 2019-08-05 Last updated: 2019-08-16Bibliographically approved
Marchiori, C. F. .., Brandell, D. & Araujo, C. M. (2019). Predicting Structure and Electrochemistry of Dilithium Thiophene-2,5-Dicarboxylate Electrodes by Density Functional Theory and Evolutionary Algorithms. The Journal of Physical Chemistry C, 123(8), 4691-4700
Open this publication in new window or tab >>Predicting Structure and Electrochemistry of Dilithium Thiophene-2,5-Dicarboxylate Electrodes by Density Functional Theory and Evolutionary Algorithms
2019 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 123, no 8, p. 4691-4700Article in journal (Refereed) Published
Abstract [en]

Organic electroactive materials are promising candidates to be TUC used as lithium insertion electrodes in the next generation of environmentally friendly battery technologies. In this work, evolutionary algorithms at interplay with density functional theory calculations have been employed to predict the crystal structure for both delithiated and lithiated phases of dilithium thiophene dicarboxylate (Li2TDC). On the basis of the resulting crystals, electronic structure modifications and voltage profiles for the lithiation process have been calculated. The obtained structure for the delithiated phase showed a well-defined salt layer intercalating the organic components, forming a so-called lithium organic framework (LOF). Upon lithiation, new structures appear which deviate from the LOF as a consequence of the reduction of the S atoms, which coordinate with the additional Li ions. The calculated average potential of similar to 1.00 V vs Li/Li+ is found to be in good agreement with experimental findings. An additional study at the molecular level has also been conducted aiming at gaining insight into the importance of the crystallographic environment on the structural and thermodynamics properties. This strategy is suitable for an initial assessment of the electrochemical process that underlies the lithiation mechanism of electrode materials. Moreover, the employed evolutionary algorithm emerges as a promising tool to predict crystal structures during lithiation, which are otherwise difficult to resolve experimentally.

National Category
Materials Chemistry Other Chemistry Topics
Identifiers
urn:nbn:se:uu:diva-379938 (URN)10.1021/acs.jpcc.8b11341 (DOI)000460365200008 ()
Funder
Swedish Research Council, 621-2014-5984Swedish Research Council Formas, 2016-00838Swedish Energy Agency, 45420-1
Available from: 2019-03-26 Created: 2019-03-26 Last updated: 2019-03-26Bibliographically approved
Zhou, Y., Pondick, J. V., Silva, J. L., Woods, J. M., Hynek, D. J., Matthews, G., . . . Cha, J. J. (2019). Unveiling the Interfacial Effects for Enhanced Hydrogen Evolution Reaction on MoS2/WTe2 Hybrid Structures. Small, 15(19), Article ID 1900078.
Open this publication in new window or tab >>Unveiling the Interfacial Effects for Enhanced Hydrogen Evolution Reaction on MoS2/WTe2 Hybrid Structures
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2019 (English)In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 15, no 19, article id 1900078Article in journal (Refereed) Published
Abstract [en]

Using the MoS2-WTe2 heterostructure as a model system combined with electrochemical microreactors and density function theory calculations, it is shown that heterostructured contacts enhance the hydrogen evolution reaction (HER) activity of monolayer MoS2. Two possible mechanisms are suggested to explain this enhancement: efficient charge injection through large-area heterojunctions between MoS2 and WTe2 and effective screening of mirror charges due to the semimetallic nature of WTe2. The dielectric screening effect is proven minor, probed by measuring the HER activity of monolayer MoS2 on various support substrates with dielectric constants ranging from 4 to 300. Thus, the enhanced HER is attributed to the increased charge injection into MoS2 through large-area heterojunctions. Based on this understanding, a MoS2/WTe2 hybrid catalyst is fabricated with an HER overpotential of -140 mV at 10 mA cm(-2), a Tafel slope of 40 mV dec(-1), and long stability. These results demonstrate the importance of interfacial design in transition metal dichalcogenide HER catalysts. The microreactor platform presents an unambiguous approach to probe interfacial effects in various electrocatalytic reactions.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2019
Keywords
electrochemical microreactors, heterostructures, hydrogen evolution reaction, interfacial effects, MoS2, WTe2 hybrid
National Category
Physical Chemistry Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-390541 (URN)10.1002/smll.201900078 (DOI)000472198100006 ()30957970 (PubMedID)
Funder
Swedish Research CouncilStandUp
Available from: 2019-08-12 Created: 2019-08-12 Last updated: 2019-08-12Bibliographically approved
Triana, C. A., Araujo, C. M., Ahuja, R., Niklasson, G. & Edvinsson, T. (2018). Modeling of Electronic Properties of Amorphous Oxides. In: Wandelt, K. (Ed.), Encyclopedia of Interfacial Chemistry:: Surface Science and Electrochemistry (pp. 319-331). Elsevier
Open this publication in new window or tab >>Modeling of Electronic Properties of Amorphous Oxides
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2018 (English)In: Encyclopedia of Interfacial Chemistry:: Surface Science and Electrochemistry / [ed] Wandelt, K., Elsevier, 2018, p. 319-331Chapter in book (Refereed)
Abstract [en]

Encyclopedia of Interfacial Chemistry: Surface Science and Electrochemistry summarizes current, fundamental knowledge of interfacial chemistry, bringing readers the latest developments in the field. As the chemical and physical properties and processes at solid and liquid interfaces are the scientific basis of so many technologies which enhance our lives and create new opportunities, its important to highlight how these technologies enable the design and optimization of functional materials for heterogeneous and electro-catalysts in food production, pollution control, energy conversion and storage, medical applications requiring biocompatibility, drug delivery, and more. This book provides an interdisciplinary view that lies at the intersection of these fields.

Place, publisher, year, edition, pages
Elsevier, 2018
Series
Encyclopedia of Interfacial Chemistry
National Category
Condensed Matter Physics
Identifiers
urn:nbn:se:uu:diva-369244 (URN)9780128097397 (ISBN)9780128098943 (ISBN)
Available from: 2018-12-11 Created: 2018-12-11 Last updated: 2019-04-10Bibliographically approved
Damas, G., Marchiori, C. F. N. & Araujo, C. M. (2018). On the Design of Donor Acceptor Conjugated Polymers for Photocatalytic Hydrogen Evolution Reaction: First-Principles Theory-Based Assessment. The Journal of Physical Chemistry C, 122(47), 26876-26888
Open this publication in new window or tab >>On the Design of Donor Acceptor Conjugated Polymers for Photocatalytic Hydrogen Evolution Reaction: First-Principles Theory-Based Assessment
2018 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, no 47, p. 26876-26888Article in journal (Refereed) Published
Abstract [en]

A set of fluorene-based polymers with a donor acceptor architecture has been investigated as a potential candidate for photocatalytic hydrogen evolution reaction. A design protocol has been employed based on first -principles theory and focusing on the following properties: (i) broad absorption spectrum to promote a higher number of photogenerated electron hole pairs, (ii) suitable redox potentials, and (iii) appropriate reaction thermodynamics using the hydrogen -binding energy as a descriptor. We have found that the polymers containing a fused -ring acceptor formed by benzo(triazole-thiadiazole) or benzo(triazole-selenodiazole) units display a suitable combination of such properties and stand out as potential candidates. In particular, PFO-DSeBTrT (poly (9,9'-dioctylfluorene)-2,7-diyl-alt-(4,7-bis(thien-2y1)-2-dodecyl-benzo-(1,2c:4,5c')-1,2,3-triazole-2,1,3-selenodiazole)) has an absorption maximum at around 950 nm for the highest occupied molecular orbital lowest unoccupied molecular orbital transition, covering a wider range of solar emission spectrum, and a reduction catalytic power of 0.78 eV. It also displays a calculated hydrogen -binding free energy of Delta G(H) = 0.02 eV, which is lower in absolute value than Furthermore, the results and trends analysis provide guidance for the rational design of novel photo-electrocatalysts. that of Pt (Delta G(H) approximate to -0.10 eV).

National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-372709 (URN)10.1021/acs.jpcc.8b09408 (DOI)000451933400012 ()
Funder
Swedish Research CouncilCarl Tryggers foundation StandUp
Available from: 2019-01-09 Created: 2019-01-09 Last updated: 2019-01-09Bibliographically approved
Zhou, Y., Silva, J. L., Woods, J. M., Pondick, J. V., Feng, Q., Liang, Z., . . . Cha, J. J. (2018). Revealing the Contribution of Individual Factors to Hydrogen Evolution Reaction Catalytic Activity. Advanced Materials, 30(18), Article ID 1706076.
Open this publication in new window or tab >>Revealing the Contribution of Individual Factors to Hydrogen Evolution Reaction Catalytic Activity
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2018 (English)In: Advanced Materials, ISSN 0935-9648, E-ISSN 1521-4095, Vol. 30, no 18, article id 1706076Article in journal (Refereed) Published
Abstract [en]

For the electrochemical hydrogen evolution reaction (HER), the electrical properties of catalysts can play an important role in influencing the overall catalytic activity. This is particularly important for semiconducting HER catalysts such as MoS2, which has been extensively studied over the last decade. Herein, on-chip microreactors on two model catalysts, semiconducting MoS2 and semimetallic WTe2, are employed to extract the effects of individual factors and study their relations with the HER catalytic activity. It is shown that electron injection at the catalyst/current collector interface and intralayer and interlayer charge transport within the catalyst can be more important than thermodynamic energy considerations. For WTe2, the site-dependent activities and the relations of the pure thermodynamics to the overall activity are measured and established, as the microreactors allow precise measurements of the type and area of the catalytic sites. The approach presents opportunities to study electrochemical reactions systematically to help establish rational design principles for future electrocatalysts.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2018
Keywords
2D TMD materials, electrochemical microreactors, hydrogen evolution reaction, individual factors, overall performance
National Category
Physical Chemistry
Identifiers
urn:nbn:se:uu:diva-356393 (URN)10.1002/adma.201706076 (DOI)000431615100009 ()29573299 (PubMedID)
Funder
Swedish Research CouncilStandUp
Available from: 2018-07-25 Created: 2018-07-25 Last updated: 2018-07-25Bibliographically approved
Lanzilotto, V., Silva, J. L., Zhang, T., Stredansky, M., Grazioli, C., Simonov, K., . . . Puglia, C. (2018). Spectroscopic Fingerprints of Intermolecular H-Bonding Interactions in Carbon Nitride Model Compounds. Chemistry - A European Journal, 24(53), 14198-14206
Open this publication in new window or tab >>Spectroscopic Fingerprints of Intermolecular H-Bonding Interactions in Carbon Nitride Model Compounds
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2018 (English)In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, no 53, p. 14198-14206Article in journal (Refereed) Published
Abstract [en]

The effect of intermolecular H-bonding interactions on the local electronic structure of N-containing functional groups (amino group and pyridine-like N) that are characteristic of polymeric carbon nitride materials p-CN(H), a new class of metal-free organophotocatalysts, was investigated. Specifically, the melamine molecule, a building block of p-CN(H), was characterized by X-ray photoelectron (XPS) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. The molecule was studied as a noninteracting system in the gas phase and in the solid state within a H-bonded network. With the support of DFT simulations of the spectra, it was found that the H-bonds mainly affect the N1s level of the amino group, leaving the N1s level of the pyridine-like N mostly unperturbed. This is responsible for a reduction of the chemical shift between the two XPS N1s levels relative to free melamine. Consequently, N K-edge NEXAFS resonances involving the amino N1s level also shift to lower photon energies. Moreover, the solid-state absorption spectra showed significant modification/quenching of resonances related to transitions from the amino N1s level to sigma* orbitals involving the NH2 termini.

Place, publisher, year, edition, pages
WILEY-V C H VERLAG GMBH, 2018
Keywords
density functional calculations, hydrogen bonds, carbon nitrides, photoelectron spectroscopy, X-ray absorption spectroscopy
National Category
Theoretical Chemistry
Identifiers
urn:nbn:se:uu:diva-366732 (URN)10.1002/chem.201802435 (DOI)000445177600028 ()30009392 (PubMedID)
Funder
Carl Tryggers foundation
Available from: 2018-12-11 Created: 2018-12-11 Last updated: 2018-12-11Bibliographically approved
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