Solar-driven atmospheric water harvesting (AWH) presents a sustainable approach for freshwater production with sunlight as the sole energy input. To address challenges posed by diurnal moisture variations and diffusiv...
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Novel self-assembled architectures have received a growing amount of attention and have significant potential for application in catalysis/electrocatalysis. Herein, we take advantage of the unique coordination and sel...
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Novel self-assembled architectures have received a growing amount of attention and have significant potential for application in catalysis/electrocatalysis. Herein, we take advantage of the unique coordination and self-assembly properties of arginine for the preparation of dendritic PtCu bimetallic nanoassemblies with tunable chemical composition and structure. Strong interactions between the arginine molecules are key in driving the self-assembly of primary nanocrystals. In addition, the strong coordination interactions between arginine and metal ions is responsible for the formation of Pt-Cu alloys. We also investigated the electrocatalytic activity of various dendritic PtCu bimetallic nanoassemblies towards the methanol oxidation reaction. PtBCUl nanoassemblies exhibited excellent electrocatalytic activity and stability in comparison with other PtCu bimetallic nanoassemblies （PtlCu3, PtlCu~） and commercial Pt black, due to their unique dendritic structures and the synergistic effect between the Pt and Cu atoms.
Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic *** supercapacitors(...
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Stretchable energy storage devices,maintaining the capability of steady operation under large mechanical strain,have become increasing more important with the development of stretchable electronic *** supercapacitors(SSCs),with high power density,modest energy density,and superior mechanical properties are regarded as one of the most promising power supplies to stretchable electronic *** polymers,such as polyaniline(PANI),polypyrrole(PPy),polythiophene(PTh)and poly(3,4-ehtylenedioxythiophene)(PEDOT),are among the well-studied electroactive materials for the construction of SSCs because of their high specific theoretical capacity,excellent electrochemical activity,light weight,and high *** effort has been devoted to developing stretchable,conductive polymer-based SSCs with different device structures,such as sandwich-type and fiber-shaped type *** review summarizes the material and structural design for con ductive polymer-based SSCs and discusses the challenge and importa nt di recti ons in this emergi ng field.
The austenite-to-martensite transformation expansion during quenching of steels from intercritical temperatures results in plastic deformation of a region of ferrite near each martensite particle. The localized ferrit...
The austenite-to-martensite transformation expansion during quenching of steels from intercritical temperatures results in plastic deformation of a region of ferrite near each martensite particle. The localized ferrite plastic strain lowers slightly the overall ductility of the ferrite and, hence, the dual-phase steel. The extent to which this occurs was investigated theoretically by determining the extent of the ferrite plastic zone, the average dislocation density within that zone, the effective overall increase in ferrite dislocation density and an associated strain ε dm . The value ε dm , when incorporated into a previous derivation of composite true uniform strain, was found to decrease the ductility of dual-phase steels. The magnitude of this decrease was largest for martensite volume fractions between 0.3 and 0.5 and was determined to be less than 0.02. La dilatation à la transformation de l'austénite en martensite au cours de la trempe des aciers à partir de températures intercritiques conduit à la déformation plastique d'une région de ferrite au voisinage de chaque particule de martensite. La déformation plastique localisée de la ferrite abaisse légèrement la ductilité générale de la ferrite et donc de l'acier diphasé. Nous avons étudié théoriquement dans quelle mesure ceci se produisait en déterminant la grandeur de la zone plastique ferritique, la densité moyenne de dislocations dans cette zone, l'accroissement effectif total de la densité de dislocations dans la ferrite et une déformation associée ε dm . La valeur de ε dm , introduite dans un calcul anténeein de la déformation uniforme vraie d'un composite, abaissait la ductilité des aciers diphasés. Cette diminution était maximale pour des fractions volumiques de martensite comprises entre 0,3 et 0,5 et elle était inférieure à 0,02. Die Umwandlung von Austenit in Martensit führt während des Abschreckens eines Stahles von interkritischen Temperaturen zu Dehnungen, durch die der Ferrit im bereich der mart
CONSPECTUS:Safe and adequate water is a global challenge due to the growing population and pollution in the wake of natural *** to clean water is a cornerstone for the further development of our modern ***-powered des...
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CONSPECTUS:Safe and adequate water is a global challenge due to the growing population and pollution in the wake of natural *** to clean water is a cornerstone for the further development of our modern ***-powered desalination and water purification have attracted much research attention due to the high solar-to-thermal conversion efficiency and ease of implementation in multiple scales,from compact,stand-alone devices for individual households to large,centralized dimensions for ***,the generation of water vapor at low temperatures below the boiling point is usually a slow process under natural *** production rate of clean water relies on the efficiencies of solar energy conversion and utilization,which can be enhanced in two directions:systems optimization and materials *** from bottom heating and volumetric heating,interfacial evaporation has been adopted recently to systematically reduce energy loss by localizing heat near the evaporation surface using photothermal ***,carbonaceous materials,narrow bandgap semiconductors,and polymers with different structures were designed to achieve thermal management and water *** this Account,we highlight the recent progress of hydrogels as a highly tunable material platform for solar-powered desalination and water *** begin by introducing how gelation chemistry endows hydrogels with desirable properties and multiscale tunability from molecular to macroscopic ***,we review three major strategies to promote efficient solar-to-vapor conversion in terms of reducing water evaporation enthalpy,optimizing heat distribution,and tailoring the evaporation ***,by selecting polymeric backbones with hydratable functional groups,the water state in hydrogels can be regulated to facilitate intermediate water,which has a lower evaporation enthalpy compared to that of the bulk *** polymer−water interaction can be
Catalysts for the oxygen reduction reaction （ORR） play an important role in fuel cells. Alternative non-precious metal catalysts with comparable ORR activity to Pt-based catalysts are highly desirable for the develo...
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Catalysts for the oxygen reduction reaction （ORR） play an important role in fuel cells. Alternative non-precious metal catalysts with comparable ORR activity to Pt-based catalysts are highly desirable for the development of fuel cells. In this work, we report for the first time a spinel MnC0204/C ORR catalyst consisting of uniform MnC0204 nanoparticles cross-linked with two-dimensional （2D） porous carbon nanosheets （abbreviated as porous MnC0204/C nanosheets）, in which glucose is used as the carbon source and NaC1 as the template. The obtained porous MnCo204/C nanosheets present the combined properties of an interconnected porous architecture and a large surface area （175.3 m2-g-1）, as well as good electrical conductivity （1.15 x 102 ***-1）. Thus, the as-prepared MnC0204/C nanosheets efficiently facilitate electrolyte diffusion and offer an expedite transport path for reactants and electrons during the ORR. As a result, the as-prepared porous MnC0204/C nanosheet catalyst exhibits enhanced ORR activity with a higher onset potential and current density than those of its counterparts, including pure MnC0204, carbon nanosheets, and Vulcan XC-72R carbon. More importantly, the porous MnC0204/C nanosheets exhibit a com- parable electrocatalytic activity but superior stability and tolerance toward methanol crossover effects than a high-performance Pt/C catalyst in alkaline medium. The synthetic strategy outlined here can be extended to other non- precious metal catalysts for application in electrochemical energy conversion.
With the rising demand for fast-charging technology in electric vehicles and portable devices,significant efforts have been devoted to the development of energy storage and conversion ***,remarkable progress has been ...
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With the rising demand for fast-charging technology in electric vehicles and portable devices,significant efforts have been devoted to the development of energy storage and conversion ***,remarkable progress has been made in the field of various energy storage and conversion devices,i.e.,lithium-ion batteries(LIBs),lithium-metal batteries(LMBs),lithium-sulfur batteries(LSBs),sodium-ion batteries(SIBs),sodium-metal batteries(SMBs),magnesium-ion batteries(MIBs),zinc-ion batteries(ZIBs),electrochemical capacitors(ECs),the corresponding electrode materials have always been the focus and difficulty to further improve the electrochemical performance of the devices.
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