Elastic Properties of 2D Ultrathin Tungsten Nitride Crystals Grown by Chemical Vapor Deposition

Abstract

3D transition metal nitrides are well recognized for their good electrical conductivity, superior mechanical properties and high chemical stability. Recently, 2D transition metal nitrides have been successfully prepared in the form of nanosheets and show potential application in energy storage. However, the synthesis of highly crystalline and well-shaped 2D nitrides layers is still in demand for the investigation of their intrinsic physical properties. Here we report the growth of ultrathin tungsten nitride crystals on SiO 2 /Si substrates by a salt-assisted chemical vapor deposition (CVD) method. High-resolution transmission microscopy verifies the as-grown samples are highly crystalline WN. The stiffness of ultrathin WN is investigated by atomic force microscopy based nanoindentation with the film suspended on circular holes. The 3D Young's modulus of few-layer (4.5 nm thick or more) WN is determined to be 3.9 × 10 2 ± 1.6 × 10 2 GPa, which is comparable with the best experimental reported values in 2D family except graphene and h-BN. The synthesis approach presented in this paper offers possibilities of producing and utilizing other highly crystalline 2D transition-metal nitride crystals.Received: ((will be filled in by the editorial staff))Revised: ((will be filled in by the editorial staff))

Plasmonic Enhanced Reactive Oxygen Species Activation on Low‐Work‐Function Tungsten Nitride for Direct Near‐Infrared Driven Photocatalysis

“…The metallic WN with high free electron density and good conductivity is quite similar to these metallic photocatalysts, and thus the strong plasmonic enhanced NIR absorption and direct NIR‐driven photocatalytic performance are highly expected. [ 9 ] However, to the best of our knowledge, application of WN as NIR‐driven photocatalyst has not caught much attentions yet. Previously, Wang et al.…”

“…The metallic WN with high free electron density and good conductivity is quite similar to these metallic photocatalysts, and thus the strong plasmonic enhanced NIR absorption and direct NIR-driven photocatalytic performance are highly expected. [9] However, to the best of our knowledge, application of WN as NIR-driven photocatalyst has not caught much attentions yet. Previously, Wang et al operate an overall-waterspitting photocatalysis with black WN under 765 nm, which enlighten us to employ real NIR light above 800 nm for the photocatalyis application [10] In this work, the theoretical calculation of DFT and finite element analysis (FEA) are carried out to investigate the electronic structure and optical property of the cubic phase (WN-cub) firstly.…”

Molten Salt-Directed Catalytic Synthesis of 2D Layered Transition-Metal Nitrides for Efficient Hydrogen Evolution

“…On the contrary, mixed salts can significantly reduce the melting point of the metal and metal oxide precursors, and lead to a liquid-gas synthesis. 10,47 Under molten state, the metal precursors melt into monomers, which have higher reaction activity and faster reaction rate. 44 Using this method, we have synthesized a family of 2D layered materials, such as MoN 1.2 , WN 1.5 , and Mo 0.7 W 0.3 N 1.2 .…”

Synthesis of Atomically Thin 1T‐TaSe2 with a Strongly Enhanced Charge‐Density‐Wave Order

“…After examined by Raman spectroscopy, the 1T-TaSe2 layers grown on SiO2/Si substrates were transferred to a Cu grid by a polymethyl-methacrylate (PMMA)-assisted transfer method. [34] Fig. 2f shows the large field view of high-angle annular-dark-field (HAADF)-STEM image of 1T-TaSe2 layers acquired at room temperature.…”