Large area growth of vertically aligned luminescent MoS2 nanosheets as potential candidate for catalysis and bio-sensing

 

Mustapha Jouiad

Materials Science & Engineering, Masdar Institute of Science and technology

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ABSTRACT:

 

MX2 (M = Mo, W, etc., X = S, Se, etc.) belongs to the transition metal dichalcogenide (TMD) family, which has a layered structure. These TMD materials show properties ranging from metallic, semiconducting to superconducting [1]. The interaction between the atoms within the plane is covalent and stronger than the interaction between the atoms residing on different planes, which is of Van Der Waals interaction type and it is relatively weak. Due to these anisotropic interactions along and between the planes, the electronic, physical, and chemical properties are also anisotropic, which give rise to interesting mechanical, electrical, electro-chemical, optical and catalytic properties. MoS2 has been a focus of study for various applications, such as hydrodesulphurization catalysis, hydrogen evolution reaction, lithium batteries, photocatalysis, sensors and field emission. MoS2 possesses good electrical conductivity and can emit light, opening possible applications such as photodetectors and optoelectronic devices [2,3]. It can also be integrated with other two-dimensional, flexible, and transparent materials.

Owing to its excellent properties and great application potential, extensive research has been carried out to develop various methods to synthesize nanosized MoS2. Along with the high crystalline quality, specific morphology, and application performance, high yield and easy fabrication are also the main factors to be considered for developing a methodology to obtain nanoscale materials. Chemical vapor deposition (CVD) technique has shown promise to generate high-quality MoS2 layers with a scalable size, controllable thickness, and excellent electronic properties.

The present work involves the growth of MoS2 NSs by rapid sulfurization of sputter coated thick Mo (10–300 nm) films using ambient pressure – CVD. Also the use of sputter-coated films is rather more economical compared to that of the e-beam deposited Mo films reported previously and low pressure CVD. This is an important step towards realization of the large-scale production of MoS2 NSs. We have used several characterization techniques, in order to gain greater insight into the growth and characteristics of the as-grown NSs. By extensive analytical measurements the in-depth growth of NSs was studied. We have confirmed that high-crystalline quality, vertically aligned straight

MoS2 NSs having properties such as visible light emission and hydrophobicity can be successfully synthesized. Based on our experimental results, a brief growth mechanism will be also discussed. These as-grown MoS2 NSs endowed with multiple qualities would be highly useful in the development of interesting and innovative application opportunities in the fields of catalysis, nano-optoelectronic, gas-sensing and bio-sensing device applications.

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References:

 

[1] J. A. Wilson and A. D. Yoffe, Adv. Phys., 1969, 18, 193–335.

[2] J. Pak et al., Nanoscale, 2015, 7, 18780–18788.

[3] L. Britnell et al., Science, 2013, 340, 1311–1314.