scholarly journals Rolling the WSSe Bilayer into Double-Walled Nanotube for the Enhanced Photocatalytic Water-Splitting Performance

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 705
Author(s):  
Lin Ju ◽  
Jingzhou Qin ◽  
Liran Shi ◽  
Gui Yang ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Water Splitting ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Stable Configuration ◽  
Photocatalytic Water Splitting ◽  
Stacking Pattern ◽  
Metal Dichalcogenides ◽  
Photocatalytic Performances ◽  
Carrier Separation

For the emerging Janus transition metal dichalcogenides (TMD) layered water-splitting photocatalysts, stacking the monolayers to form bilayers has been predicted to be an effective way to improve their photocatalytic performances. To achieve this, the stacking pattern plays an important role. In this work, by means of the density functional theory calculations, we comprehensively estimate energetical stability, light absorption and redox capacity of Janus WSSe bilayer with different stacking patterns. Unfortunately, the Janus WSSe bilayer with the most stable configuration recover the out-of-plane symmetry, which is not in favor of the photocatalytic reactions. However, rolling the Janus WSSe bilayer into double-walled nanotube could stabilize the appropriate stacking pattern with an enhanced instinct dipole moment. Moreover, the suitable band edge positions, high visible light absorbance, outstanding solar-to-hydrogen efficiency (up to 28.48%), and superior carrier separation promise the Janus WSSe double-walled nanotube the potential for the photocatalytic water-splitting application. Our studies not only predict an ideal water-splitting photocatalyst, but also propose an effective way to improve the photocatalytic performances of Janus layered materials.

Transition-metal dichalcogenides/Mg(OH)2 van der Waals heterostructures as promising water-splitting photocatalysts: a first-principles study

2019 ◽  
Vol 21 (4) ◽  
pp. 1791-1796 ◽  
Author(s):  
Yi Luo ◽  
Sake Wang ◽  
Kai Ren ◽  
Jyh-Pin Chou ◽  
Jin Yu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
First Principles ◽  
Van Der Waals ◽  
Transition Metal Dichalcogenides ◽  
Van Der Waals Heterostructures ◽  
Photocatalytic Water Splitting ◽  
First Principles Study ◽  
Metal Dichalcogenides

We found that the MoS2/Mg(OH)2 and WS2/Mg(OH)2 vdW heterostructures are promising for application in photocatalytic water splitting.

Boosting the photocatalytic hydrogen evolution performance of C2N monolayer coupled with MoSi2N4: density-functional theory calculations

2021 ◽  
Author(s):  
Jian Zeng ◽  
Liang Xu ◽  
Youwen Yang ◽  
Xin Luo ◽  
Hongju Li ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Evolution ◽  
Water Splitting ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Two Dimensional ◽  
Functional Theory ◽  
Photocatalytic Hydrogen Evolution ◽  
Photocatalytic Water Splitting ◽  
Separation Rate

Very recently, a vital two-dimensional material MoSi2N4 is successfully synthesized experimentally. However, pure MoSi2N4 has some inherent shortcomings in photocatalytic water splitting to produce hydrogen. especially the low separation rate...

scholarly journals Single-atom doping of MoS2 with manganese enables ultrasensitive detection of dopamine: Experimental and computational approach

2020 ◽  
Vol 6 (32) ◽  
pp. eabc4250 ◽  
Author(s):  
Yu Lei ◽  
Derrick Butler ◽  
Michael C. Lucking ◽  
Fu Zhang ◽  
Tunan Xia ◽  
...  
Keyword(s):  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Single Atom ◽  
Buffer Solution ◽  
Dopamine Detection ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
Metal Doped

Two-dimensional transition metal dichalcogenides (TMDs) emerged as a promising platform to construct sensitive biosensors. We report an ultrasensitive electrochemical dopamine sensor based on manganese-doped MoS2 synthesized via a scalable two-step approach (with Mn ~2.15 atomic %). Selective dopamine detection is achieved with a detection limit of 50 pM in buffer solution, 5 nM in 10% serum, and 50 nM in artificial sweat. Density functional theory calculations and scanning transmission electron microscopy show that two types of Mn defects are dominant: Mn on top of a Mo atom (MntopMo) and Mn substituting a Mo atom (MnMo). At low dopamine concentrations, physisorption on MnMo dominates. At higher concentrations, dopamine chemisorbs on MntopMo, which is consistent with calculations of the dopamine binding energy (2.91 eV for MntopMo versus 0.65 eV for MnMo). Our results demonstrate that metal-doped layered materials, such as TMDs, constitute an emergent platform to construct ultrasensitive and tunable biosensors.

Pristine edge structures of T′′-phase transition metal dichalcogenides (ReSe2, ReS2) atomic layers

Nanoscale ◽  
2020 ◽  
Vol 12 (32) ◽  
pp. 17005-17012
Author(s):  
Xiya Chen ◽  
Bao Lei ◽  
Yong Zhu ◽  
Jiadong Zhou ◽  
Zheng Liu ◽  
...  
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Microscopy Imaging ◽  
Functional Theory ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Metal Dichalcogenides ◽  
T Phase

Atomically sharp pristine edges of ReSe2 atomic layers were identified with scanning transmission electron microscopy imaging and density functional theory calculations.

scholarly journals Uniaxial strain-induced phase transition in the 2D topological semimetal IrTe2

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Christopher W. Nicholson ◽  
Maxime Rumo ◽  
Aki Pulkkinen ◽  
Geoffroy Kremer ◽  
Björn Salzmann ◽  
...  
Keyword(s):  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Gain Control ◽  
Density Functional Theory Calculations ◽  
Uniaxial Strain ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Topological Semimetal ◽  
Topological States ◽  
Metal Dichalcogenides

AbstractStrain is ubiquitous in solid-state materials, but despite its fundamental importance and technological relevance, leveraging externally applied strain to gain control over material properties is still in its infancy. In particular, strain control over the diverse phase transitions and topological states in two-dimensional transition metal dichalcogenides remains an open challenge. Here, we exploit uniaxial strain to stabilize the long-debated structural ground state of the 2D topological semimetal IrTe2, which is hidden in unstrained samples. Combined angle-resolved photoemission spectroscopy and scanning tunneling microscopy data reveal the strain-stabilized phase has a 6 × 1 periodicity and undergoes a Lifshitz transition, granting unprecedented spectroscopic access to previously inaccessible type-II topological Dirac states that dominate the modified inter-layer hopping. Supported by density functional theory calculations, we show that strain induces an Ir to Te charge transfer resulting in strongly weakened inter-layer Te bonds and a reshaped energetic landscape favoring the 6×1 phase. Our results highlight the potential to exploit strain-engineered properties in layered materials, particularly in the context of tuning inter-layer behavior.

scholarly journals A rationally designed two-dimensional MoSe2/Ti2CO2 heterojunction for photocatalytic overall water splitting: simultaneously suppressing electron–hole recombination and photocorrosion

2021 ◽  
Author(s):  
Cen-Feng Fu ◽  
Xingxing Li ◽  
Jinlong Yang
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Rational Design ◽  
Transition Metal Dichalcogenides ◽  
Two Dimensional ◽  
Electron Hole ◽  
Photocatalytic Water Splitting ◽  
Overall Water Splitting ◽  
Metal Dichalcogenides ◽  
Hole Recombination

The two challenges of electron–hole recombination and photocorrosion for two-dimensional transition metal dichalcogenides in the application of photocatalytic water splitting are simultaneously suppressed by rational design of heterojunctions.

Probing the active sites of newly predicted stable Janus scandium dichalcogenides for photocatalytic water-splitting

2019 ◽  
Vol 9 (18) ◽  
pp. 4981-4989 ◽  
Author(s):  
Xiaoyong Yang ◽  
Amitava Banerjee ◽  
Rajeev Ahuja
Keyword(s):  
Transition Metal ◽  
Water Splitting ◽  
Precious Metal ◽  
Active Sites ◽  
Transition Metal Dichalcogenides ◽  
Photocatalytic Water Splitting ◽  
Metal Dichalcogenides

The Janus structures of transition metal dichalcogenides with intrinsic dipoles have recently drawn attention as efficient candidates in the class of non-precious metal photocatalysts for water splitting.

scholarly journals Imaging and identification of point defects in PtTe2

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Kuanysh Zhussupbekov ◽  
Lida Ansari ◽  
John B. McManus ◽  
Ainur Zhussupbekova ◽  
Igor V. Shvets ◽  
...  
Keyword(s):  
Point Defects ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Density Functional Theory Calculations ◽  
Charge Carrier Mobility ◽  
Scanning Tunneling Spectroscopy ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Recombination Rates ◽  
And Performance

AbstractThe properties and performance of two-dimensional (2D) materials can be greatly affected by point defects. PtTe2, a 2D material that belongs to the group 10 transition metal dichalcogenides, is a type-II Dirac semimetal, which has gained a lot of attention recently due to its potential for applications in catalysis, photonics, and spintronics. Here, we provide an experimental and theoretical investigation of point defects on and near the surface of PtTe2. Using scanning tunneling microscopy and scanning tunneling spectroscopy (STS) measurements, in combination with first-principle calculations, we identify and characterize five common surface and subsurface point defects. The influence of these defects on the electronic structure of PtTe2 is explored in detail through grid STS measurements and complementary density functional theory calculations. We believe these findings will be of significance to future efforts to engineer point defects in PtTe2, which is an interesting and enticing approach to tune the charge-carrier mobility and electron–hole recombination rates, as well as the site reactivity for catalysis.

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