scholarly journals Two-Dimensional Indium Selenide for Sulphur Vapour Sensing Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1396 ◽  
Author(s):  
Daniel Andres-Penares ◽  
Rodolfo Canet-Albiach ◽  
Jaume Noguera-Gomez ◽  
Juan P. Martínez-Pastor ◽  
Rafael Abargues ◽  
...  
Keyword(s):  
Surface Passivation ◽  
Volume Diffusion ◽  
Volume Ratio ◽  
Vapour Phase ◽  
Two Dimensional ◽  
Proof Of Concept ◽  
Sensing Applications ◽  
Before And After ◽  
Surface Localization ◽  
2D Nanosheets

Surface-to-volume ratio in two-dimensional (2D) materials highlights among their characteristics as an inherent and intrinsic advantage taking into account their strong sensitivity to surface effects. For this reason, we have proposed in this work micromechanically exfoliated 2D nanosheets of InSe as an optical vapour sensor. As a proof of concept, we used 2-mercaptoethanol as the chemical analyte in vapour phase to monitor the change of the InSe photoluminescence (PL) before and after exposure to the analyte. For short vapour exposure times (at low analyte concentration), we found a PL enhancement of InSe nanosheets attributed to the surface localization of Se defects. For long vapour exposure times (or higher concentrations) a PL reduction is observed, probably due to the diffusion of molecules within the nanosheet. These results confirm the capability of 2D InSe as a photoluminescent sensor of vapours, because of its sensitivity to surface passivation or volume diffusion of molecules.

scholarly journals Effects of Acetone Vapor on the Exciton Band Photoluminescence Emission from Single- and Few-Layer WS2 on Template-Stripped Gold

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1913 ◽  
Author(s):  
Samantha Matthews ◽  
Chuan Zhao ◽  
Hao Zeng ◽  
Frank V. Bright
Keyword(s):  
Chemical Sensing ◽  
2D Materials ◽  
Volume Ratio ◽  
Exciton Band ◽  
Two Dimensional ◽  
Acetone Vapor ◽  
Force Microscopy ◽  
Sensing Applications ◽  
Atomic Force ◽  
Pl Emission

Two-dimensional (2D) materials are being used widely for chemical sensing applications due to their large surface-to-volume ratio and photoluminescence (PL) emission and emission exciton band tunability. To better understand how the analyte affects the PL response for a model 2D platform, we used atomic force microscopy (AFM) and co-localized photoluminescence (PL) and Raman mapping to characterize tungsten disulfide (WS2) flakes on template-stripped gold (TSG) under acetone challenge. We determined the PL-based response from single- and few-layer WS2 arises from three excitons (neutral, A0; biexciton, AA; and the trion, A−). The A0 exciton PL emission is the most strongly quenched by acetone whereas the A− PL emission exhibits an enhancement. We find the PL behavior is also WS2 layer number dependent.

scholarly journals Two-Dimensional Nanomaterials for Gas Sensing Applications: The Role of Theoretical Calculations

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 851 ◽  
Author(s):  
Yamei Zeng ◽  
Shiwei Lin ◽  
Ding Gu ◽  
Xiaogan Li
Keyword(s):  
Electric Fields ◽  
Gas Sensing ◽  
Theoretical Calculations ◽  
High Surface ◽  
Volume Ratio ◽  
Two Dimensional ◽  
Sensing Properties ◽  
Sensing Applications ◽  
Gas Sensing Properties ◽  
2D Nanomaterials

Two-dimensional (2D) nanomaterials have attracted a large amount of attention regarding gas sensing applications, because of their high surface-to-volume ratio and unique chemical or physical gas adsorption capabilities. As an important research method, theoretical calculations have been massively applied in predicting the potentially excellent gas sensing properties of these 2D nanomaterials. In this review, we discuss the contributions of theoretical calculations in the study of the gas sensing properties of 2D nanomaterials. Firstly, we elaborate on the gas sensing mechanisms of 2D layered nanomaterials, such as the traditional charge transfer mechanism, and a standard for distinguishing between physical and chemical adsorption, from the perspective of theoretical calculations. Then, we describe how to conduct a theoretical analysis to explain or predict the gas sensing properties of 2D nanomaterials. Thirdly, we discuss three important methods that have been applied in order to improve the gas sensing properties, that is, defect functionalization (vacancy, edge, grain boundary, and doping), heterojunctions, and electric fields. Among these strategies, theoretical calculations play a very important role in explaining the mechanisms underlying the enhanced gas sensing properties. Finally, we summarize both the advantages and limitations of the theoretical calculations, and present perspectives for further research on the 2D nanomaterials-based gas sensors.

scholarly journals Two-dimensional iodine-monofluoride epitaxy on WSe2

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yung-Chang Lin ◽  
Sungwoo Lee ◽  
Yueh-Chiang Yang ◽  
Po-Wen Chiu ◽  
Gun-Do Lee ◽  
...  
Keyword(s):  
Density Functional ◽  
Surface Passivation ◽  
Hexagonal Lattice ◽  
Chemical Vapor ◽  
Growth Promoter ◽  
Two Dimensional ◽  
Epitaxial Relationship ◽  
Chemical Vapor Deposition Growth ◽  
Scanning Transmission ◽  
Great Possibility

AbstractInterhalogen compounds (IHCs) are extremely reactive molecules used for halogenation, catalyst, selective etchant, and surface modification. Most of the IHCs are unstable at room temperature especially for the iodine-monofluoride (IF) whose structure is still unknown. Here we demonstrate an unambiguous observation of two-dimensional (2D) IF bilayer grown on the surface of WSe2 by using scanning transmission electron microscopy and electron energy loss spectroscopy. The bilayer IF shows a clear hexagonal lattice and robust epitaxial relationship with the WSe2 substrate. Despite the IF is known to sublimate at −14 °C and has never found as a solid form in the ambient condition, but surprisingly it is found stabilized on a suitable substrate and the stabilized structure is supported by a density functional theory. This 2D form of IHC is actually a byproduct during a chemical vapor deposition growth of WSe2 in the presence of alkali metal halides as a growth promoter and requires immediate surface passivation to sustain. This work points out a great possibility to produce 2D structures that are unexpected to be crystallized or cannot be obtained by a simple exfoliation but can be grown only on a certain substrate.

scholarly journals One-pot Bottom-up Synthesis of 2D Graphene Derivative: Application in Biomolecular Recognition and Nanozyme Activity

2021 ◽  
Author(s):  
Subrata Pandit ◽  
Mrinmoy De
Keyword(s):  
Growth Control ◽  
Biomolecular Recognition ◽  
Two Dimensional ◽  
One Pot ◽  
Bottom Up ◽  
2D Nanosheets

The synthesis of two-dimensional (2D) nanosheets such as graphene and their derivatives through bottom-up approach has many advantages such as growth control and functionalization, but it is always challenging to...

scholarly journals Understanding the structure and dynamics of hydrogenases by ultrafast and two-dimensional infrared spectroscopy

2019 ◽  
Vol 10 (39) ◽  
pp. 8981-8989 ◽  
Author(s):  
Marius Horch ◽  
Janna Schoknecht ◽  
Solomon L. D. Wrathall ◽  
Gregory M. Greetham ◽  
Oliver Lenz ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Two Dimensional ◽  
Proof Of Concept ◽  
Concept Study ◽  
Structure And Dynamics ◽  
Two Dimensional Infrared Spectroscopy

A proof-of-concept study on a catalytic [NiFe] intermediate reveals structural and dynamical details of hydrogenases by ultrafast and two-dimensional infrared spectroscopies.

Quantum transport, electronic properties and molecular adsorptions in graphene

2021 ◽  
Vol 35 (08) ◽  
pp. 2130001
Author(s):  
Yoshitaka Fujimoto
Keyword(s):  
Electronic Properties ◽  
Quantum Transport ◽  
Density Functional ◽  
Field Effect Transistors ◽  
Electronic Conductivity ◽  
Volume Ratio ◽  
Functional Study ◽  
Sensor Applications ◽  
Sensing Applications ◽  
High Electronic Conductivity

Molecular sensor applications are used in different fields including environmental monitoring and medical diagnosis. Graphene, a single atomic layer consisting of the hexagonally arranged carbon material, is one of the most promising materials for ideal channels in field-effect transistors to be used as electronic sensing applications owing to its lightweight, mechanical robustness, high electronic conductivity and large surface-to-volume ratio. This paper provides a review of molecular adsorptions, electronic properties and quantum transport of graphene based on the first-principles density-functional study. The adsorption properties of environmentally polluting or toxic molecules and electronic transport of graphene are revealed. The possibility of detecting these molecules selectively is also discussed for designing the graphene-based sensor applications.

A Novel Micromechanical Resonator Using Two-Dimensional Phononic Crystal Slab

2011 ◽  
Vol 254 ◽  
pp. 195-198
Author(s):  
Nan Wang ◽  
Fu Li Hsiao ◽  
Moorthi Palaniapan ◽  
Ming Lin Julius Tsai ◽  
Jeffrey B.W. Soon ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Phononic Crystal ◽  
Acoustic Resonance ◽  
Two Dimensional ◽  
Free Standing ◽  
Sensing Applications ◽  
Aln Film ◽  
Digital Transducers ◽  
Square Array ◽  
Quality Factor Q

Two-dimensional (2-D) Silicon phononic crystal (PnC) slab of a square array of cylindrical air holes in a 10μm thick free-standing silicon plate with line defects is characterized as a cavity-mode PnC resonator. Piezoelectric aluminum nitride (AlN) film is deployed as the inter-digital transducers (IDT) to transmit and detect acoustic waves, thus making the whole microfabrication process CMOS-compatible. Both the band structure of the PnC and the transmission spectrum of the proposed PnC resonator are analyzed and optimized using finite element method (FEM). The measured quality factor (Q factor) of the microfabricated PnC resonator is over 1,000 at its resonant frequency of 152.46MHz. The proposed PnC resonator shows promising acoustic resonance characteristics for RF communications and sensing applications.

A reversible thermo-responsive 2D Zn(ii) coordination polymer as a potential self-referenced luminescent thermometer

2020 ◽  
Vol 8 (7) ◽  
pp. 2525-2532 ◽  
Author(s):  
Lincy Tom ◽  
M. R. P. Kurup
Keyword(s):  
Coordination Polymer ◽  
Temperature Sensing ◽  
Two Dimensional ◽  
Sensing Applications

A two dimensional Zn(ii) coordination polymer with exceptional reversible luminescence thermochromic behavior has been synthesized for temperature sensing applications.

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