scholarly journals Exfoliated transition metal dichalcogenide nanosheets for supercapacitor and sodium ion battery applications

2019 ◽  
Vol 6 (8) ◽  
pp. 190437 ◽  
Author(s):  
Santanu Mukherjee ◽  
Jonathan Turnley ◽  
Elisabeth Mansfield ◽  
Jason Holm ◽  
Davi Soares ◽  
...  

Growing concerns regarding the safety, flammability and hazards posed by Li-ion systems have led to research on alternative rechargeable metal-ion electrochemical storage technologies. Among the most notable of these are Na-ion supercapacitors and batteries, motivated, in part, by the similar electrochemistry of Li and Na ions. However, sodium ion batteries (SIBs) come with their own set of issues, especially the large size of the Na + ion, its relatively sluggish kinetics and low energy densities. This makes the development of novel materials and appropriate electrode architecture of absolute significance. Transition metal dichalcogenides (TMDs) have attracted a lot of attention in this regard due to their relative ease of exfoliation, diverse morphologies and architectures with superior electronic properties. Here, we study the electrochemical performance of Mo-based two-dimensional (2D) layered TMDs (e.g. MoS 2 , MoSe 2 and MoTe 2 ), exfoliated in a superacid, for battery and supercapacitor applications. The exfoliated TMD flakes were interfaced with reduced graphene oxide (rGO) to be used as composite electrodes. Electron microscopy, elemental mapping and Raman spectra were used to analyse the exfoliated material and confirm the formation of 2D TMD/rGO layer morphology. For supercapacitor applications in aqueous electrolyte, the sulfide-based TMD (MoS 2 ) exhibited the best performance, providing an areal capacitance of 60.25 mF cm −2 . For SIB applications, TMD electrodes exhibited significantly higher charge capacities than the neat rGO electrode. The initial desodiation capacities for the composite electrodes are 468.84 mAh g −1 (1687.82 C g −1 ), 399.10 mAh g −1 (1436.76 C g −1 ) and 387.36 mAh g −1 (1394.49 C g −1 ) for MoS 2 , MoSe 2 and MoTe 2 , respectively. Also, the MoS 2 and MoSe 2 composite electrodes provided a coulombic efficiency of near 100 % after a few initial cycles.

2021 ◽  
Vol 3 (1) ◽  
pp. 272-278
Author(s):  
Pilar G. Vianna ◽  
Aline dos S. Almeida ◽  
Rodrigo M. Gerosa ◽  
Dario A. Bahamon ◽  
Christiano J. S. de Matos

The scheme illustrates a monolayer transition-metal dichalcogenide on an epsilon-near-zero substrate. The substrate near-zero dielectric constant is used as the enhancement mechanism to maximize the SHG nonlinear effect on monolayer 2D materials.


Nanoscale ◽  
2021 ◽  
Author(s):  
Albert Bruix ◽  
Jeppe Vang Lauritsen ◽  
Bjork Hammer

Nanomaterials based on MoS2 and related transition metal dichalcogenides are remarkably versatile; MoS2 nanoparticles are proven catalysts for processes such as hydrodesulphurization and the hydrogen evolution reaction, and transition metal...


Author(s):  
Wenqian Han ◽  
Guannan Guo ◽  
Yan Xia ◽  
Jing Ning ◽  
Yuwei Deng ◽  
...  

Transition metal dichalcogenides (TMDs) are promising anode materials for sodium-ion batteries (SIBs), but suffer from low rate capability and poor cycling stability. Here, we describe our efforts in designing a...


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Förste ◽  
Nikita V. Tepliakov ◽  
Stanislav Yu. Kruchinin ◽  
Jessica Lindlau ◽  
Victor Funk ◽  
...  

Abstract The optical properties of monolayer and bilayer transition metal dichalcogenide semiconductors are governed by excitons in different spin and valley configurations, providing versatile aspects for van der Waals heterostructures and devices. Here, we present experimental and theoretical studies of exciton energy splittings in external magnetic field in neutral and charged WSe2 monolayer and bilayer crystals embedded in a field effect device for active doping control. We develop theoretical methods to calculate the exciton g-factors from first principles for all possible spin-valley configurations of excitons in monolayer and bilayer WSe2 including valley-indirect excitons. Our theoretical and experimental findings shed light on some of the characteristic photoluminescence peaks observed for monolayer and bilayer WSe2. In more general terms, the theoretical aspects of our work provide additional means for the characterization of single and few-layer transition metal dichalcogenides, as well as their heterostructures, in the presence of external magnetic fields.


RSC Advances ◽  
2016 ◽  
Vol 6 (60) ◽  
pp. 54874-54879 ◽  
Author(s):  
Wenhui Wang ◽  
Zhongti Sun ◽  
Wenshuai Zhang ◽  
Quanping Fan ◽  
Qi Sun ◽  
...  

Recently, two-dimensional (2D) layered transition metal dichalcogenides (LTMDs) have attracted great scientific interest for ion battery applications.


Nanoscale ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 201-209 ◽  
Author(s):  
Songsong Zhou ◽  
Jinliang Ning ◽  
Jianwei Sun ◽  
David J. Srolovitz

Using alloying and/or twisting between layers to achieve the type I direct bandgaps vertical heterojunction in transition metal dichalcogenide family of MX2 (M = {Mo, W}, X = {S, Se}).


Nanoscale ◽  
2018 ◽  
Vol 10 (35) ◽  
pp. 16365-16397 ◽  
Author(s):  
Vipul Agarwal ◽  
Kaushik Chatterjee

Nanosheets of transition metal dichalcogenide (TMDs), the graphene-like two-dimensional (2D) materials, exhibit a unique combination of properties and have attracted enormous research interest for a wide range of applications including catalysis, functional electronics, solid lubrication, photovoltaics, energy materials and most recently in biomedical applications.


2018 ◽  
Vol 9 ◽  
pp. 780-788 ◽  
Author(s):  
Haitao Chen ◽  
Mingkai Liu ◽  
Lei Xu ◽  
Dragomir N Neshev

Background: Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) with intrinsically crystal inversion-symmetry breaking have shown many advanced optical properties. In particular, the valley polarization in 2D TMDCs that can be addressed optically has inspired new physical phenomena and great potential applications in valleytronics. Results: Here, we propose a TMDC–nanoantenna system that could effectively enhance and direct emission from the two valleys in TMDCs into diametrically opposite directions. By mimicking the emission from each valley of the monolayer of WSe2 as a chiral point-dipole emitter, we demonstrate numerically that the emission from different valleys is directed into opposite directions when coupling to a double-bar plasmonic nanoantenna. The directionality derives from the interference between the dipole and quadrupole modes excited in the two bars, respectively. Thus, we could tune the emission direction from the proposed TMDC–nanoantenna system by tuning the pumping without changing the antenna structure. Furthermore, we discuss the general principles and the opportunities to improve the average performance of the nanoantenna structure. Conclusion: The scheme we propose here can potentially serve as an important component for valley-based applications, such as non-volatile information storage and processing.


2018 ◽  
Vol 47 (15) ◽  
pp. 5602-5613 ◽  
Author(s):  
Xinyi Chia ◽  
Martin Pumera

Here, we explore the electrochemical and catalytic trends across the extensive library of layered transition metal dichalcogenides beyond MoS2.


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