Cold Rolling Texture in Ordered CuZn Alloy

The texture of 80% cold rolling CuZn ordered alloy was investigated. The development of rolling texturein 50%Cu-50%Zn(at.) alloy has been characterized by a inhomogenous {111} fiber texture with strong {111} <112>component, which is significantly different from the conventional Cu-Zn alloys. The main characters of cold rollingtextures in ordered CuZn alloy are obviously similar to that in IF steel with bcc structure or ordered Fe3A1-basedalloys with imperfect B2 structure. From the rolling texture obtained by experiments and simulations,it can be estimated that main deformation mechanism are characterized by the activation of slip systems with <111> Burgersvector in CuZn ordered alloy.

Structural and chemical transformations of CuZn alloy nanoparticles under reactive redox atmospheres:An in situ TEM study

Alloying metals to form intermetallics has been proven effective in tuning the chemical properties of metal-based catalysts.However,intermetallic alloys can undergo structural and chemical transformations under reactive conditions,leading to changes in their catalytic function.Elucidating and understanding these transformations are crucial for establishing relevant structureperformance relationships and for the rational design of alloy-based catalysts.In this work,we used CuZn alloy nanoparticles(NPs)as a model material system and employed in situ transmission electron microscopy(TEM)to investigate the structural and chemical changes of CuZn NPs under H_(2),O_(2)and their mixture.Our results show how CuZn NPs undergo sequential transformations in the gas mixture at elevated temperatures,starting with gradual leaching and segregation of Zn,followed by oxidation at the NP surface.The remaining copper at the core of particles can then engage in dynamic behavior,eventually freeing itself from the zinc oxide shell.The structural dynamics arises from an oscillatory phase transition between Cu and Cu_(2)O and is correlated with the catalytic water formation,as confirmed by in situ mass spectrometry(MS).Under pure H_(2)or O_(2)atmosphere,we observe different structural evolution pathways and final chemical states of CuZn NPs compared to those in the gas mixture.These results clearly demonstrate that the chemical state of alloy NPs can vary considerably under reactive redox atmospheres,particularly for those containing elements with distinct redox properties,necessitating the use of in situ or detailed ex situ characterizations to gain relevant insights into the states of intermetallic alloy-based catalysts and structure-activity relationships.

Two-dimensional CuO nanosheets-induced MOF composites and derivatives for dendrite-free zinc-ion batteries

Uncontrollable dendrite growth and side reactions resulting in short operating life and low Coulombic efficiency have severely hindered the further development of aqueous zinc-ion batteries(AZIBs).In this work,we designed to grow zeolitic imidazolate framework-8(ZIF-8)uniformly on CuO nanosheets(NSs)and prepared carbon-coated CuZn alloy NSs(CuZn@C NSs)by calcination under H_(2)/Ar atmosphere.As reflected by extended X-ray absorption fine structure(EXAFS),density functional theory(DFT),in-situ Raman,the Cu–Zn and Zn–N bonds present in CuZn@C NSs act as zincophilic sites to uniformly absorb Zn ions and inhibit the formation of Zn dendrites.At the same time,CuZn@C NSs hinder the direct contact between zinc anode and electrolyte,preventing the occurrence of side reactions.More impressively,the symmetric cells constructed with CuZn@C NSs anodes exhibited excellent zinc plating/exfoliation performance and long life cycle at different current densities with low voltage hysteresis.In addition,low polarization,high capacity retention,long cycle life over 1000 cycles at 5 A∙g^(−1) were achieved when CuZn@C NSs were used as anodes for CuZn@C/V_(2)O_(5)full cells.