Two-dimensional (2D) materials have aroused considerable research interest owing to their potential applications in nanoelectronics and optoelectronics. Thermodynamic stability of 2D structures inevitably affects the performance and power consumption of the fabricated nanodevices. Black arsenic (b-As), as a cousin of black phosphorus, has presented extremely high anisotropy in physical properties. However, systematic research on structural stability of b-As is still lacking. Herein, we demonstrated the detailed analysis on structural metastability of the natural b-As, and determined its existence conditions in terms of two essential thermodynamic variables, hydrostatic pressure and temperature. Our results confirmed that b-As can survive only below 0.7 GPa, and then irreversibly transforms to gray arsenic, consistent with our theoretical calculations. Furthermore, a thermal annealing strategy was developed to precisely control the thickness of the b-As flake, and it sublimates at 300 °C. These results could pave the way for 2D b-As in many promising applications.
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http://dx.doi.org/10.1021/acs.jpclett.3c02214 | DOI Listing |
Adv Mater
January 2025
MOE Key Laboratory for UV Light-Emitting Materials and Technology, Department of Physics, Northeast Normal University, Changchun, 130024, P. R. China.
Avoiding severe structural distortion, irreversible phase transition, and realizing the stabilized multielectron redox are vital for promoting the development of high-performance NASICON-type cathode materials for sodium-ion batteries (SIBs). Herein, a high-entropy NaVFeTiMnCr(PO) (HE-NaTMP) cathode material is prepared by ultrafast high-temperature shock, which inhibits the possibility of phase separation and achieves reversible and stable multielectron transfer of 2.4/2.
View Article and Find Full Text PDFNat Commun
January 2025
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, China.
Renewable energy-driven electrocatalytic nitrate reduction reaction presents a low-carbon and sustainable route for ammonia synthesis under mild conditions. Yet, the practical application of this process is currently hindered by unsatisfactory electrocatalytic activity and long-term stability. Herein we achieve high-rate ammonia electrosynthesis using a stable amorphous/crystalline dual-phase Cu catalyst.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
Single-atom catalysts have attracted a significant amount of attention due to their exceptional atomic utilization and high efficiency in a range of catalytic reactions. However, these systems often face thermodynamic instability, leading to agglomeration under the operational conditions. In this study, we investigate the interactions of 12 types of catalytic atoms (Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, Au, and Bi) on three crystalline phases (1T, 1T', and 2H) of six transition metal dichalcogenide layers (MoS, MoSe, MoTe, WS, WSe, and WTe) using first-principles calculations.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011.
From molecular dynamics (MD) simulations of melt-quenching and thermal aging procedures in pure Ag, Cu, Ag-Cu binary alloys, and Cu-Zr binary alloys, we have identified two distinct amorphous phases for a metastable undercooled liquid: the homogeneous L-phase with low shear rigidity and the heterogenous G-phase with much higher shear rigidity and a heterogeneity length scale Λ. Here, we examine two-phase equilibration studies showing that the G-phase melts to form the L-phase above ~1,000 K, which then transforms to form the crystal (X) phase; however, below the melting point of the G-Phase (~990 K), the X- and G-phases do not transform into each other. We suggest the presence of a G-phase is likely responsible for embrittlement often observed in metallic glasses.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, University of Pennsylvania, 231 S 34th St, Philadelphia, Pennsylvania 19104, United States.
Molecular Zr phosphides are extremely rare, with no examples containing a one-coordinated and terminal triple-bonded phosphorus atom. We report here an isolable and relatively stable Zr phosphide complex, [(PN)Zr≡P{μ-Na(OEt)}] (), stemming from a cyclometalated Zr-hydride, [(PN)(PN')Zr(H)] (), and NaPH. Complex is prepared from two- or one-electron reductions of precursors [(PN)ZrCl] () or metastable Zr[(PN)ZrCl], respectively.
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