1,720,983 research outputs found
Enhancing glucose oxidation: exploring 3D Pt nanowire frameworks for electrochemical studies
No full textHere, we report the use of highly reproducible free-standing 3D Pt nanowire frameworks (3D Pt NFs) to investigate the electrochemical oxidation of glucose. To create this unique Pt NFs, we utilize a lipidic bicontinuous cubic phase as a template. The resulting Pt NFs exhibits a unique 3D single diamond morphology with Fd3m symmetry. This intricate structure provides a large surface area and high electrocatalytic efficiency, making it more sensitive to glucose detection. Small Angle X-ray Scattering and Transmission electron microscopy investigations provided valuable insights into the nanoarchitecture of 3D Pt NFs. It highlights the interconnected nature of the nanowires and showcases the potential for optimized electrochemical performance. Very high current densities are registered for the glucose oxidation reactions at 3D Pt NFs during cyclic voltammetry investigations. This knowledge aids in the design and development of advanced electrocatalytic systems, fuel cells, biosensors, and other devices that leverage the unique characteristics of the 3D Pt framework. Graphical abstract: This study explores 3D Pt NFs for electrochemical glucose oxidation. Using a phytantriol template with two non-intersecting aqueous channels (A), Pt is electrodeposited in one channel (B), resulting in the formation of 3D Pt NFs after template washing (C). This approach demonstrates the potential for efficient glucose oxidation in the structured nanowire frameworks. (Figure presented.)</p
Electrodeposition of thermoelectric materials
No full textThermoelectric (TE) materials produce electrical energy when exposed to a thermal gradient and so have unsurprisingly gathered increasing interest as a promising tool in the route to reduced carbon energy emissions. However, many synthetic routes currently involve high-temperatures, oxygen-free environments and harsh chemical reagents. Electrochemistry offers an attractive alternate synthetic route for similar materials at greatly reduced temperatures, without the need for strong chemical reductants. This review looks at recent developments in the electrodeposition of TE materials, highlighting promising materials and techniques. It also outlines key challenges that must be addressed in order to advance the readiness of this technology for wider implementation.</p
Controlled fabrication of highly ordered platinum nanostructures using pulsed electrodeposition
No full textPulsed potential (PP) electrodeposition was utilized for the first time to fabricate three-dimensional (3D) platinum (Pt) nanostructures within phytantriol-based double diamond cubic templates, both with or without 20 % w/w Brij-56 as a pore swelling agent. Unlike conventional direct potential (DP) deposition, the PP approach yielded Pt nanostructures with markedly enhanced uniformity and superior lattice ordering. Small Angle X-ray Scattering (SAXS) revealed that PP-grown structures exhibited sharp, well-defined Bragg peaks corresponding to lattice parameters of 134.2 ± 2.1 Å without Brij-56 and 236.7 ± 2.5 Å with 20 % w/w Brij-56, whereas DP-grown structures showed broader, less distinct peaks with smaller lattice parameter (130.7 ± 1.9 Å and 197.1 ± 2.8 Å, respectively). Notably, In-situ SAXS measurements provided real-time insights into the evolution of 3D Pt nanostructures, enabling direct monitoring of orientational and lateral ordering within the templated phases. High resolution SEM further confirmed the superior quality of PP-grown structures, revealing highly ordered 3D nanowire network with uniform pore sizes of 89.5 ± 1.3 (without Brij-56) and 102.0 ± 0.7 Å (with 20 % w/w Brij-56). Overall, these findings highlight the effectiveness of PP electrodeposition in mitigating structural inhomogeneities, establishing it as a powerful strategy for fabricating well-ordered 3D Pt nanostructures.</p
A novel binary composite of CuCoNi-MOF/MoO3 with exceptional capacitance as electrode material for supercapacitors
No full textMetal-organic framework (MOF), a new type of electrode material with a porous structure, has shown promise as a good choice for supercapacitors in the next generation of energy storage devices. These research endeavors initiated the development of a doping technique and the creation of a composite material using solvothermal synthesis. This study involves the successful synthesis of CuCo-MOF and CuCoNi-MOF by introducing Co and Ni metals into the Cu-MOF. The CuCoNi-MOF is then combined with MoO3 to form a novel binary composite known as CuCoNi-MOF/MoO3. These prepared materials are then subjected to several physiochemical and electrochemical characterization techniques. The electrochemical characteristics of the prepared samples are estimated using a three-electrode cell setup. The analysis included cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge (GCD). The examination of the CV reveals that the binary composite CuCoNi-MOF/MoO3 exhibits exceptional capacitance (937.5 Fg−1 at 5 mVs−1) in comparison to the other materials that were synthesized. Moreover, the GCD study reveals that it has a capacity of 1364.69 Fg−1 at 0.5 Ag−1. Furthermore, it retained 91.5 % of its capacity after 5000 cycles demonstrating its exceptional stability. Owing to the exceptional electrochemical properties of CuCoNi-MOF/MoO3, it is employed as the positive electrode and activated carbon (Actsingle bondC) as a negative electrode for device fabrication. The supercapattery (CuCoNi-MOF/MoO3||Act-C) showed an excellent specific capacitance of 218.83 Fg−1 at 1 Ag−1 along with an outstanding energy density of 59.57 Wh.kg−1 and power density of 704.9 W.kg−1. Moreover, the assembled supercapattery device shows remarkable stability of 95.2 % at 10 Ag−1 after 15,000 cycles
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
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