Tantalum disulphide belongs to the group of transition metal dichalcogenides (TMDs) and has attracted attention for its unique structural, electronic, and catalytic properties. Herein, we report the edge properties of single‐layer 2H‐TaS₂ studied by using density functional theory calculations, because the knowledge of the edge morphology, stability, and surface energy is essential for the determination of nanoparticle shapes and understanding the nature of catalytically active sites. We calculate the grand canonical potential of TaS₂ clusters having various edge morphologies to evaluate the edge energies of the Ta‐edge and S‐edge terminated surfaces. Under S‐rich conditions, the most likely shape of TaS₂ is a deformed hexagon dominated by the Ta‐edge covered by S monomers, while the triangular shape is preferred under S‐poor conditions. Exposed edges of the single‐layer TaS₂ are susceptible to oxidation in air because both oxygen adsorption and substitution at the edge are strongly exothermic, −0.96 and −2.20 eV for single O atom, respectively. The XPS calculation shows that specific initial steps of oxidative process (adsorption, vacancy creation, substitution) are unlikely to be distinguished in the XPS spectra due to small shift of respective binding energies, but initial edge oxidation of TaS₂ should be observable by an asymmetry of the Ta 4f doublet towards higher binding energies.

中文翻译：

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单层2H-TaS2的原子尺度边缘形态，稳定性和氧化

二硫化钽属于过渡金属二硫化碳（TMDs）组，并因其独特的结构，电子和催化性能而受到关注。在此，我们报告使用密度泛函理论计算研究的单层2H-TaS ₂的边缘性质，因为边缘形态，稳定性和表面能的知识对于确定纳米颗粒的形状和理解催化性质至关重要。活动站点。我们计算具有各种边缘形态的TaS ₂簇的正则势，以评估Ta-edge和S-edge终止表面的边缘能量。在富S条件下，TaS ₂最可能的形状是一个变形的六边形，以被S单体覆盖的Ta-edge为主，而在S-poor条件下，三角形是首选。单层TaS _2的暴露边缘易于在空气中氧化，因为边缘处的氧吸附和取代都是强烈放热的，单个O原子分别为-0.96和-2.20 eV。XPS计算表明，由于各个结合能的微小变化，在XPS光谱中不太可能区分氧化过程的特定初始步骤（吸附，空位形成，取代），但是TaS _2的初始边缘氧化应该可以通过不对称观察到。 Ta 4f的二重态趋向于更高的结合能。