scholarly journals Vertically oriented MoS2 nanosheets with vast exposed edges for enhanced electrocatalytic hydrogen evolution

2021 ◽  
Vol 245 ◽  
pp. 03019
Author(s):  
Meisheng Han ◽  
Jie Yu
Keyword(s):  
Hydrogen Evolution ◽  
High Performance ◽  
Transition Metal Dichalcogenides ◽  
Structure Of Metal ◽  
Special Area ◽  
Metal Dichalcogenides ◽  
Complex Preparation ◽  
Catalytic Stability ◽  
Electrochemical Water Splitting ◽  
A Current

Molybdenum disulfide (MoS2), a typical two-dimensional transition metal dichalcogenides, is a promising candidate for electrochemical water splitting catalysis due to its ultrahigh special area and highly exposed active edge sites. The main challenges restricted the wider application for MoS2-based nanomaterials are the complex preparation process and the high overpotential. Here, we design a novel and facile sealed vessel to synthesize vertical oriented MoS2 nanosheets electrocatalyst with vast exposed edges. Benefiting from the unique vertically-oriented structural and compositional characteristics, the MoS2 nanosheets with 10-20 layers exhibits superior hydrogen evolution reaction (HER) performance with a small overpotential of 135.2 mV at a current density of 10 mA∙cm-2 and low Tafel slope of 82.5 mV∙dec-1 as well as extraordinary catalytic stability over 5000 cycles. Importantly, the sealed vessel reactor system may open up a versatile and potential synthetic way to construct various morphologies and structure of metal dichalcogenides for high-performance energy storage and conversions devices.

Basal Plane Activation in Monolayer MoTe2 for Hydrogen Evolution Reaction via Phase Boundaries

2020 ◽  
Author(s):  
Yiqing Chen ◽  
Pengfei Ou ◽  
Xiaohan Bie ◽  
Jun Song
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Basal Plane ◽  
High Performance ◽  
Hydrogen Adsorption ◽  
Transition Metal Dichalcogenides ◽  
Stable Phase ◽  
Great Promise ◽  
Phase Boundaries ◽  
Metal Dichalcogenides

<p>Two-dimensional transition metal dichalcogenides (2D TMDCs) have attracted tremendous interest as one prominent material group promising inexpensive <a>electrocatalysts for hydrogen evolution reaction (HER)</a>. In the present study, using <a>monolayer MoTe<sub>2</sub> as a representative, we demonstrated that </a>phase boundaries can provide a viable pathway to activate the basal plane of 2D TMDCs for enhanced HER performance. Comprehensive first-principles calculations have been performed to examine the energetics and structural stabilities of possible 2H/1T’ phase boundary configurations. Three categories of sites, Te, Mo and hollow sites, have been identified in energetically stable phase boundaries, as potential catalytic centers for HER, all indicating enhanced HER activity than the pristine basal lattice. In particular, the hollow sites, a new group of sites induced by phase boundaries, show great promise by exhibiting a Gibbs free energy near the thermoneutral value for hydrogen adsorption, comparable to that of Pt. The mechanisms underlying hydrogen adsorption at phase boundaries were then revealed, shown to be attributed to the unique local hydrogen adsorption geometries and electronic structures at phase boundaries. Our study clarifies the important mechanistic aspects underlying hydrogen activation at phase boundaries, providing valuable theoretical insights towards designing new class of high-performance HER electrocatalysts based on 2D TMDCs.</p>

Basal Plane Activation in Monolayer MoTe2 for Hydrogen Evolution Reaction via Phase Boundaries

2020 ◽  
Author(s):  
Yiqing Chen ◽  
Pengfei Ou ◽  
Xiaohan Bie ◽  
Jun Song
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Basal Plane ◽  
High Performance ◽  
Hydrogen Adsorption ◽  
Transition Metal Dichalcogenides ◽  
Stable Phase ◽  
Great Promise ◽  
Phase Boundaries ◽  
Metal Dichalcogenides

<p>Two-dimensional transition metal dichalcogenides (2D TMDCs) have attracted tremendous interest as one prominent material group promising inexpensive <a>electrocatalysts for hydrogen evolution reaction (HER)</a>. In the present study, using <a>monolayer MoTe<sub>2</sub> as a representative, we demonstrated that </a>phase boundaries can provide a viable pathway to activate the basal plane of 2D TMDCs for enhanced HER performance. Comprehensive first-principles calculations have been performed to examine the energetics and structural stabilities of possible 2H/1T’ phase boundary configurations. Three categories of sites, Te, Mo and hollow sites, have been identified in energetically stable phase boundaries, as potential catalytic centers for HER, all indicating enhanced HER activity than the pristine basal lattice. In particular, the hollow sites, a new group of sites induced by phase boundaries, show great promise by exhibiting a Gibbs free energy near the thermoneutral value for hydrogen adsorption, comparable to that of Pt. The mechanisms underlying hydrogen adsorption at phase boundaries were then revealed, shown to be attributed to the unique local hydrogen adsorption geometries and electronic structures at phase boundaries. Our study clarifies the important mechanistic aspects underlying hydrogen activation at phase boundaries, providing valuable theoretical insights towards designing new class of high-performance HER electrocatalysts based on 2D TMDCs.</p>

scholarly journals Rational strain engineering of single-atom ruthenium on nanoporous MoS2 for highly efficient hydrogen evolution

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kang Jiang ◽  
Min Luo ◽  
Zhixiao Liu ◽  
Ming Peng ◽  
Dechao Chen ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Catalytic Properties ◽  
Transition Metal Dichalcogenides ◽  
Strain Engineering ◽  
Single Atom ◽  
Catalytic Behavior ◽  
Metal Dichalcogenides ◽  
A Current

AbstractMaximizing the catalytic activity of single-atom catalysts is vital for the application of single-atom catalysts in industrial water-alkali electrolyzers, yet the modulation of the catalytic properties of single-atom catalysts remains challenging. Here, we construct strain-tunable sulphur vacancies around single-atom Ru sites for accelerating the alkaline hydrogen evolution reaction of single-atom Ru sites based on a nanoporous MoS2-based Ru single-atom catalyst. By altering the strain of this system, the synergistic effect between sulphur vacancies and Ru sites is amplified, thus changing the catalytic behavior of active sites, namely, the increased reactant density in strained sulphur vacancies and the accelerated hydrogen evolution reaction process on Ru sites. The resulting catalyst delivers an overpotential of 30 mV at a current density of 10 mA cm−2, a Tafel slope of 31 mV dec−1, and a long catalytic lifetime. This work provides an effective strategy to improve the activities of single-atom modified transition metal dichalcogenides catalysts by precise strain engineering.

Highly electroconductive and uniform WS2 film growth by sulfurization of W film using diethyl sulfide

2021 ◽  
Author(s):  
Yoobeen Lee ◽  
Jin Won Jung ◽  
Jin Seok Lee
Keyword(s):  
Transition Metal ◽  
Grain Boundaries ◽  
High Performance ◽  
Film Growth ◽  
Transition Metal Dichalcogenides ◽  
Electronic Systems ◽  
Intrinsic Defects ◽  
Diethyl Sulfide ◽  
Metal Dichalcogenides

The reduction of intrinsic defects, including vacancies and grain boundaries, remains one of the greatest challenges to produce high-performance transition metal dichalcogenides (TMDCs) electronic systems. A deeper comprehension of the...

scholarly journals High-performance flexible nanoscale transistors based on transition metal dichalcogenides

2021 ◽  
Author(s):  
Alwin Daus ◽  
Sam Vaziri ◽  
Victoria Chen ◽  
Çağıl Köroğlu ◽  
Ryan W. Grady ◽  
...  
Keyword(s):  
Transition Metal ◽  
High Performance ◽  
Transition Metal Dichalcogenides ◽  
Metal Dichalcogenides ◽  
Nanoscale Transistors

Size-dependent phase stability in transition metal dichalcogenide nanoparticles controlled by metal substrates

Nanoscale ◽  
2021 ◽  
Author(s):  
Albert Bruix ◽  
Jeppe Vang Lauritsen ◽  
Bjork Hammer
Keyword(s):  
Transition Metal ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Phase Stability ◽  
Transition Metal Dichalcogenides ◽  
Transition Metal Dichalcogenide ◽  
Metal Substrates ◽  
Size Dependent ◽  
Metal Dichalcogenides

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...

scholarly journals Robust trap effect in transition metal dichalcogenides for advanced multifunctional devices

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Lei Yin ◽  
Peng He ◽  
Ruiqing Cheng ◽  
Feng Wang ◽  
Fengmei Wang ◽  
...  
Keyword(s):  
Transition Metal ◽  
High Performance ◽  
Infrared Detector ◽  
Transition Metal Dichalcogenides ◽  
Two Dimensional ◽  
Electric Transport ◽  
Defect Engineering ◽  
Fast Switching ◽  
Metal Dichalcogenides ◽  
Poor Stability

Abstract Defects play a crucial role in determining electric transport properties of two-dimensional transition metal dichalcogenides. In particular, defect-induced deep traps have been demonstrated to possess the ability to capture carriers. However, due to their poor stability and controllability, most studies focus on eliminating this trap effect, and little consideration was devoted to the applications of their inherent capabilities on electronics. Here, we report the realization of robust trap effect, which can capture carriers and store them steadily, in two-dimensional MoS2xSe2(1-x) via synergistic effect of sulphur vacancies and isoelectronic selenium atoms. As a result, infrared detection with very high photoresponsivity (2.4 × 105 A W−1) and photoswitching ratio (~108), as well as nonvolatile infrared memory with high program/erase ratio (~108) and fast switching time, are achieved just based on an individual flake. This demonstration of defect engineering opens up an avenue for achieving high-performance infrared detector and memory.

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