Redox polymers are a class of high-capacity, low-cost electrode materials for electrochemical energy storage, butthe mechanisms governing their cycling stability are not well understood. Here we investigate the effect...
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Redox polymers are a class of high-capacity, low-cost electrode materials for electrochemical energy storage, butthe mechanisms governing their cycling stability are not well understood. Here we investigate the effect of anionson the longevity of a p-dopable polymer through comparing two aqueous zinc-based electrolytes. Galvanostaticcycling studies reveal the polymer has better capacity retention in the presence of triflate anions than that withsulfate anions. Based on electrode microstructural analysis and evolution profiles of the cell stacking pressure, theorigin of capacity decay is ascribed to mechanical fractures induced by volume change of the polymer activematerials during repeated cycling. The volume change of the polymer with the triflate anion is 61% less than thatwith the sulfate anion, resulting in fewer cracks in the electrodes. The difference is related to the different anionsolvation structures—the triflate anion has fewer solvated water molecules compared with the sulfate anion,leading to smaller volume expansion. This work highlights that anions with low solvation degree are preferablefor long-term cycling.
Northern Thailand is home to several Arabica coffee-growing regions, including Mae-kampong, Teentok, Mae-lord, and Monngo Valleys, whose coffees are featured throughout this study. These coffees have distinct aromas a...
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Carbon-based materials with tunable properties have emerged as promising candidates to replace Pt-based catalysts for accelerating oxygen reduction reaction(ORR)in fuel cells or metal-air *** this work,we constructed ...
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Carbon-based materials with tunable properties have emerged as promising candidates to replace Pt-based catalysts for accelerating oxygen reduction reaction(ORR)in fuel cells or metal-air *** this work,we constructed a carbon hybrid which consists of one-dimensional(1D)carbon nanotubes and flake-like carbons by pyrolysis of leaf-like metal-organic *** optimal hybrid electrocatalyst of Fe_(7%)-L-CNT-900 possesses the desired features for ORR,including active Fe species,high degree of graphitization,large specific surface area,and hierarchical porous ***,Fe_(7%)-L-CNT900 performs a high electrocatalytic activity for ORR with a half-wave potential of 0.88 V,which is comparable to that of Pt/C(20 wt.%).This strategy provides an insight into the investigation of highly efficient and low-cost composite electrocatalyst for oxygen reduction reaction.
Next-generation nanoelectronic, energy, and quantum technologies require increasingly stringent thermal, optical, mechanical, and electrical properties of component materials, often surpassing the limits of widely use...
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Next-generation nanoelectronic, energy, and quantum technologies require increasingly stringent thermal, optical, mechanical, and electrical properties of component materials, often surpassing the limits of widely used materials such as silicon. Diamond, an ultrawide bandgap semiconductor, is a promising material for these applications because of its very high stiffness, thermal conductivity, and electron mobility. However, incorporating diamond into devices that require high-quality metal-diamond interfaces is challenging. In this work, we use a suite of electron microscopy measurements to reveal an ultrathin amorphous carbon layer that emerges at metal-diamond interfaces after electron beam lithography. Using extreme ultraviolet scatterometry, we nondestructively determine lower bounds on the layer's Young's modulus and thermal conductivity, which at >230GPa and >1.1 W/(mK) are indicative of a diamondlike form of amorphous carbon with high sp3 bonding. However, extreme ultraviolet coherent diffractive imaging reflectometry and energy-dispersive x-ray spectroscopy measurements indicate a low and likely inhomogeneous density in the range of 1–2g/cm3. The low density of such a stiff and conductive layer could indicate that it contains nanometer-scale voids or atomic-scale vacancies. The appearance of this unusual layer illustrates the nanofabrication challenges for diamond and highlights the need for better techniques to characterize surfaces and interfaces in nanoscale devices.
By coupling well-designed moderate-refractive-index Mie resonators to monolayer semiconductors, we have demonstrated efficient modulation of two-dimensional excitons in multiple dimensions: far-field excitonic radiati...
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We have developed an optical feedback control system with synchronous control of active particles to study collective motion in nature. Fish-like vortex is observed within a circular confined geometry based on the par...
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Optothermal manipulation of particles at fluid interfaces was studied with a film of gold nanoparticles assembled at aqueous/oil interfaces. The unique optothermal behaviors of particles and fluid interfaces under opt...
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The realization of two-dimensional multiferroics offers significant potential for nanoscale device functionality. However, type-I two-dimensional multiferroics with strong magnetoelectric coupling, enabling electric f...
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The realization of two-dimensional multiferroics offers significant potential for nanoscale device functionality. However, type-I two-dimensional multiferroics with strong magnetoelectric coupling, enabling electric field control of spin, remain scarce. In this study, using density functional theory and Monte Carlo simulations, we predict that the niobium phthalocyanine covalent organic framework (NbPc COF) monolayer exhibits type-I multiferroic behavior, with a ferroelectric transition occurring above room temperature. Remarkably, the strong magnetoelectric coupling in NbPc COF monolayer arises from the same origin of magnetism and ferroelectricity. Our findings offer flexible pathways for the design and development of organic nanoscale multiferroic devices with broad applications.
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