Electronic Properties and Chemical Reactivity of TiS2 Nanoflakes

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• 作者：Clotilde S. Cucinotta ; Kapildeb Dolui ; Henrik Pettersson ; Quentin M. Ramasse ; Edmund Long ; Sean E. O鈥橞rian ; Valeria Nicolosi ; Stefano Sanvito
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：July 9, 2015
• 年：2015
• 卷：119
• 期：27
• 页码：15707-15715
• 全文大小：431K
• ISSN：1932-7455

文摘

Transition metal dichalcogenides have a laminar structure, with strongly covalently bonded layers weakly interacting through van der Waals forces. They are of special interest also because of their unique properties once exfoliated in nanoflakes. We analyze the microstructure of oxidized TiS₂ nanoflakes with atomically resolved scanning transmission electron microscopy and propose a comprehensive model for their reactivity by means of first-principles simulations. In particular we find that reaction to water proceeds from the edges of the flake, while it is thermodynamically possible but kinetically hindered in the middle, unless it is initiated by the presence of a surface vacancy. Importantly O substitution for S allows fine-tuning control of the flake bandgap, paving the way for the use of TiS_2-xO_x alloys as surface catalysts and photovoltaic materials.