1,721,006 research outputs found

    Hierarchical Bi2WO6 embedded nanoporous thin films as photoanodes for PEC water splitting

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    To reach climate goals and reduce global warming, a critical challenge is to decarbonize the energy network and switch to renewable energy sources. However, the intermittent nature of renewable energy raises the need for sustainable methods to store large amounts of renewable energy. Photoelectrochemical (PEC) water splitting offers a promising solution to convert and store renewable energy as hydrogen. This work focuses on a nanoporous Bi2WO6 thin film as a stable, large bandgap protective photoanode for PEC water splitting. We synthesized Bi2WO6 microspheres and nanoflakes using a well-established hydrothermal method and produced nanoporous Bi2WO6 thin films using a citrato-complex aqueous solution-gel method. These films were modified by embedding them with Bi2WO6 microspheres or nanoflakes. Photoelectrochemical characterization shows comparable performance for all thin film types, with an onset potential of 0.2 V vs. RHE, a current density of 0.31 mA/cm2 at 1.23 V vs. RHE under 1.5 sun illumination, and stable operation for 1 hour. This performance is competitive with or superior to existing literature for nanoporous Bi2WO6 thin films. This paper demonstrates that the citratocomplex aqueous solution-gel method is a viable approach for fabricating high-quality nanoporous Bi2WO6 thin films for PEC applications, enhancing particle integration and surface attachment.This research was supported by the BE-HyFE project funded by the Federal Energy Transition Fund by FPS Economy (Belgium), as well as by Vlaamse Veerkracht. The authors also thank, PhD Candidates Ms. Nele Debusschere and Ms. Naomi Billiet for performing the XRD measurements, Dr. Ing. Saskia Hoekx for STEM analysis, Dr. Pieter Levecque for the discussions and guidance early on in the project, and Prof. Dr. Ir. Koen Vandewal for the advice on UV–VIS analysis of the thin films

    Synergy or Antagonism? Exploring the Interplay of SnO2 and an N‑OMC Carbon Capture Medium for the Electrochemical CO2 Reduction toward Formate

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    Closing the anthropogenic carbon cycle by means of the sustainable electrochemical CO2 reduction (eCO(2)R) toward formate (FA) is a promising strategy for CO2 abatement, clearing the path toward a carbon neutral future. Currently, three possible reaction pathways have been identified for the eCO(2)R toward FA, all of which are initiated by the adsorption of CO2 on the electrocatalyst's surface. Therefore, a possible strategy to enhance the availability of CO2 near the active sites is to combine an active electrocatalyst material (here, SnO2) with a known carbon capture medium (here, nitrogen-doped ordered mesoporous carbon (N-OMC)). SnO2 was introduced in situ during the N-OMC synthesis, yielding SnO2-N-OMCs. We approached the state of the art for Sn-based N-doped carbon electrocatalysts in terms of performance under industrially relevant currents with an average FEFA of 59% for SnO2-N-OMC (6) and 61% for SnO2-N-OMC (2). Moreover, the SnO2-N-OMC electrocatalysts require a low overpotential, courtesy of the N-OMC support, compared to the state of the art, for the selective conversion of CO2 toward FA at the industrially relevant current density of 100 mA cm(-2). Additionally, the 24 h stability of the best performing SnO2-N-OMC electrocatalysts is explored, and pulverization/agglomeration and in situ SnO2 reduction are identified as major degradation pathways, allowing future research to be steered more accurately toward more stable Sn-based electrocatalysts for the eCO(2)R toward FA. An optimal combination of both the SnO2 species and the N-OMC carbon capture medium could result in a synergistic effect, especially when utilization of the N-OMC support material is optimized to morphologically stabilize the SnO2 active species.K.V.D. received financial support through a PhD fellowship strategic basic research (1S83320N) from the Research Foundation Flanders (FWO). Additionally, this project received funding in the framework of the Catalisti cluster SBO project CO2PERATE (“All renewable CCU based on formic acid integrated in an industrial micro-grid”), with financial support of VLAIO (Flemish Agency for Innovation and Entrepreneurship) (UA & VITO). Furthermore, this research was supported by the Interreg 2 Seas-program 2014− 2020, cofunded by the European Regional Development Fund under subsidy contract no. E2C 2S03-019 (UA & VITO). D.B. and D.P. acknowledge the support from European Union’s Horizon 2020 MSCA-ITN programme under grant agreement no. 955650 (CATCHY). S.H. is financially supported through a PhD fellowship strategic basic research (1S42623N) from the Research Foundation Flanders (FWO). R.J. received financial support of the federal Energy Transition Fund by FPS Economy. T.A. acknowledges funding from the University of Antwerp Research fund (BOF). We acknowledge Prof. Tom Hauffman and Kitty Baert from the Electrochemical and Surface Engineering research group (SURF) at the VUB (Vrije Universiteit Brussel) for the XPS measurements, Prof. Christophe Vande Velde from the Intelligence in Processes, Advanced Catalysts and Solvents (iPRACS, UAntwerp) research group for the XRD analysis, and Prof. Pegie Cool, Prof. Vera Meynen, and Radu-George Ciocarlan from the Laboratory of Adsorption and Catalysis (LADCA, UAntwerp) for the nitrogen physisorption and Raman spectroscopy measurements

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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