Stanene the New Gas Sensing Wonder Material: Current Status and Future Prospects (original) (raw)

Stanene: Atomically Thick Free- standing Layer of 2D Hexagonal Tin OPEN

Scientific Reports, 2016

Stanene is one of most important of 2D materials due to its potential to demonstrate room temperature topological effects due to opening of spin-orbit gap. In this pursuit we report synthesis and investigation of optical properties of stanene up to few layers, a two-dimensional hexagonal structural analogue of graphene. Atomic scale morphological and elemental characterization using HRTEM equipped with SAED and EDAX detectors confirm the presence of hexagonal lattice of Sn atoms. The position of Raman peak along with the inter-planar 'd' spacing obtained from SAED for prepared samples are in good agreement with that obtained from first principles calculations and confirm that the sheets are not (111) α-Sn sheets. Further, the optical signature calculated using density functional theory at ~191 nm and ~233 nm for low buckled stanene are in qualitative agreement with the measured UV-Vis absorption spectrum. AFM measurements suggest interlayer spacing of ~0.33 nm in good agreement with that reported for epitaxial stanene sheets. No traces of oxygen were observed in the EDAX spectrum suggesting the absence of any oxidized phases. This is also confirmed by Raman measurements by comparing with oxidized stanene sheets. Two dimensional (2D) layered materials have recently gained renewed interest due to their exotic electronic properties along with high specific surface area. The prospects of exploiting these properties in sensing, catalysis, energy storage, protective coatings and electrochromism have witnessed a paradigm shift towards the exploration of these sophisticated 2D materials. The exemplary performance of graphene 1 which is among the first of these elemental 2D materials have initiated a runaway effect in the pursuit of studying alternative 2D materials. Even though graphene has tunable exotic electronic properties 2 , the spin-orbit (SO) coupling is weak 3-5 limiting its applications as spin filters, topological insulators etc. Topological insulators by their very nature force the electrons to travel on the surface at very high speeds thereby finding useful applications in electronic and photonic devices. Exploration of group IV elements using first principles calculations have revealed that the SO coupling increases as the atomic weight of the basis atoms in the honeycomb lattice 6,7. Tin is one of the heaviest elements in this series having strong spin-orbit coupling making it a promising applicant for room temperature topological insulator 8. Thus there is an urgent need to discover novel 2D materials in the post graphene age to overcome its deficiencies. Here we report the synthesis of few-layer stanene (FLS) using ultra-fast laser-material interactions. FLS is analogous to few-layer graphene and can be visualized by replacing carbon atoms by tin on a graphene lattice. Structural characterization performed using high resolution transmission electron microscopy (HRTEM) equipped with energy dispersive X-ray analysis (EDAX) and selected area electron diffraction (SAED) detectors confirm the presence of hexagonal lattice of Sn atoms. EDAX and comparative Raman studies that oxide phases are absent and rules out the possibility of (111) α-Sn sheets. Height profile measured using atomic force micros-copy (AFM) suggests interlayer separation of ~3.3 Å and in good agreement with that of recently reported epitax-ial stanene. Further the UV-Vis spectrum and Raman spectrum are in good agreement with the optical spectra and phonon frequencies calculated using first principles techniques. The structural characterization along with optical signature suggests the synthesis of free standing stanene sheets. Results and Discussions Free standing stanene sheets were synthesized by impinging pulses from a tunable Ti:Saphire ultra-fast femto second laser (140 femto-second pulse width and 80 MHz repetition rate) on to a target in liquid medium. This interaction of femo-second laser pulse due to inverse Bremsstrahlung multiphoton absorption process 9 induce non-equilibrium conditions 10. This we hypothesize initiates the change of phase from tetragonal structure of

Recent advances in graphene based gas sensors

Graphene, a single, one-atom-thick sheet of carbon atoms arranged in a honeycomb lattice and thetwo-dimensional building block for carbon materials, has attracted great interest for a wide range ofapplications. Due to its superior properties such as thermo-electric conduction, surface area and mechan-ical strength, graphene materials have inspired huge interest in sensing of various chemical species. Inthis timely review, we discuss the recent advancement in the field of graphene based gas sensors withemphasis on the use of modified graphene materials. Further, insights of theoretical and experimentalaspects associated with such systems are also discussed with significance on the sensitivity and selectivityof graphene towards various gas molecules. The first section introduces graphene, its synthesis methodsand its physico-chemical properties. The second part focuses on the theoretical approaches that discussthe structural improvisations of graphene for its effective use as gas sensing materials. The third sectiondiscusses the applications of pristine and modified graphene materials in gas sensing applications. Vari-ous graphene modification methods are discussed including using dopants and defects, decoration withmetal/metal oxide nanoparticles, and functionalization with polymers. Finally, a discussion on the futurechallenges and perspectives of this enticing field of graphene sensors for gas detection is provided.

Two-dimensional materials for gas sensors: from first discovery to future possibilities

Surface Innovations, 2018

Semiconductor gas sensors have been developed so far on empirical bases, but now recent innovative materials for advancing gas sensor technology have been made available for further developments. Two-dimensional (2D) materials have gained immense attention since the advent of graphene. This attention inspired researchers to explore a new family of potential 2D materials. The superior structural, mechanical, optical and electrical properties of 2D materials made them attractive for next-generation smart device applications. There are considerable improvements and research studies on graphene, molybdenum disulfide (MoS2), tungsten disulfide (WS2), tin sulfide (SnS2), black phosphorus and other 2D materials in the field of sensing devices. These materials have been reported to be used perfectly for sensing target gases at parts per million and parts per billion levels. A wide variety of mechanisms have been reported as main functions of 2D materials in sensing the target gas in gas sen...

Stanene: Atomically Thick Free- standing Layer of 2D Hexagonal Tin

Stanene is one of most important of 2D materials due to its potential to demonstrate room temperature topological effects due to opening of spin-orbit gap. In this pursuit we report synthesis and investigation of optical properties of stanene up to few layers, a two-dimensional hexagonal structural analogue of graphene. Atomic scale morphological and elemental characterization using HRTEM equipped with SAED and EDAX detectors confirm the presence of hexagonal lattice of Sn atoms. The position of Raman peak along with the inter-planar 'd' spacing obtained from SAED for prepared samples are in good agreement with that obtained from first principles calculations and confirm that the sheets are not (111) α-Sn sheets. Further, the optical signature calculated using density functional theory at ~191 nm and ~233 nm for low buckled stanene are in qualitative agreement with the measured UV-Vis absorption spectrum. AFM measurements suggest interlayer spacing of ~0.33 nm in good agreement with that reported for epitaxial stanene sheets. No traces of oxygen were observed in the EDAX spectrum suggesting the absence of any oxidized phases. This is also confirmed by Raman measurements by comparing with oxidized stanene sheets. Two dimensional (2D) layered materials have recently gained renewed interest due to their exotic electronic properties along with high specific surface area. The prospects of exploiting these properties in sensing, catalysis, energy storage, protective coatings and electrochromism have witnessed a paradigm shift towards the exploration of these sophisticated 2D materials. The exemplary performance of graphene 1 which is among the first of these elemental 2D materials have initiated a runaway effect in the pursuit of studying alternative 2D materials. Even though graphene has tunable exotic electronic properties 2 , the spin-orbit (SO) coupling is weak 3–5 limiting its applications as spin filters, topological insulators etc. Topological insulators by their very nature force the electrons to travel on the surface at very high speeds thereby finding useful applications in electronic and photonic devices. Exploration of group IV elements using first principles calculations have revealed that the SO coupling increases as the atomic weight of the basis atoms in the honeycomb lattice 6,7. Tin is one of the heaviest elements in this series having strong spin-orbit coupling making it a promising applicant for room temperature topological insulator 8. Thus there is an urgent need to discover novel 2D materials in the post graphene age to overcome its deficiencies. Here we report the synthesis of few-layer stanene (FLS) using ultra-fast laser-material interactions. FLS is analogous to few-layer graphene and can be visualized by replacing carbon atoms by tin on a graphene lattice. Structural characterization performed using high resolution transmission electron microscopy (HRTEM) equipped with energy dispersive X-ray analysis (EDAX) and selected area electron diffraction (SAED) detectors confirm the presence of hexagonal lattice of Sn atoms. EDAX and comparative Raman studies that oxide phases are absent and rules out the possibility of (111) α-Sn sheets. Height profile measured using atomic force micros-copy (AFM) suggests interlayer separation of ~3.3 Å and in good agreement with that of recently reported epitax-ial stanene. Further the UV-Vis spectrum and Raman spectrum are in good agreement with the optical spectra and phonon frequencies calculated using first principles techniques. The structural characterization along with optical signature suggests the synthesis of free standing stanene sheets. Results and Discussions Free standing stanene sheets were synthesized by impinging pulses from a tunable Ti:Saphire ultra-fast femto second laser (140 femto-second pulse width and 80 MHz repetition rate) on to a target in liquid medium. This interaction of femo-second laser pulse due to inverse Bremsstrahlung multiphoton absorption process 9 induce non-equilibrium conditions 10. This we hypothesize initiates the change of phase from tetragonal structure of

Gas sensing of a saturated tin/defective graphene device

2014

tralia-The sensitivity and selectivity of defective graphene to gases is enhanced by implanting single metal adatoms into vacancy sites. Knowledge of the behavior of these devices under the incremental adsorption of gas molecules until saturation is essential for determining the sensitivity of the device in realistic situations as well as for evaluating the applicability of the device in molecular capture and storage. We present a DFT study of incremental gas adsorption of CO 2 , NO 2 , SO 2 and H 2 S gases on tin adatom-double vacancy graphene system, in the presence and absence of O 2. Within the NEGF formalism, we analyze the sensitivity and selectivity of the saturated device to the gas species, showing distinctive transport features for each of the gas species.

Graphene and g-C3N4-Based Gas Sensors

Journal of Nanotechnology, 2022

The efficient monitoring of the environment is currently gaining a continuous growing interest in view of finding solutions for the global pollution issues and their associated climate change. In this sense, two-dimensional (2D) materials appear as one of highly attractive routes for the development of efficient sensing devices due, in particular, to the interesting blend of their superlative properties. For instance, graphene (Gr) and graphitic carbon nitride g-C3N4 (g-CN) have specifically attracted great attention in several domains of sensing applications owing to their excellent electronic and physical-chemical properties. Despite the high potential they offer in the development and fabrication of high-performance gas-sensing devices, an exhaustive comparison between Gr and g-CN is not well established yet regarding their electronic properties and their sensing performances such as sensitivity and selectivity. Hence, this work aims at providing a state-of-the-art overview of th...

Recent Advances on Graphene-Based Gas Sensors

Russian Journal of Physical Chemistry A, 2020

Owing to its unprecedented structural, electronic and mechanical properties, graphene, a singleatomic sheet of carbon atoms, is effectively used to detect chemical species. In this work, adsorption of gaseous molecules, mainly toxic (NO 2 , NO, NH 3 , CO, CO 2 , HF, H 2 S, etc.) and volatile organic compounds (VOCs), on graphene and modified graphene (GO, rGO) has been reviewed. The gas sensing ability of graphene is enhanced by doping with heteroatoms, and functionalizing it with many groups, such as hydroxyl, epoxy, etc. Recent advances in detection of gaseous molecules by graphene and modified graphene, coupled with metal and metal oxide nanoparticles, which have high response and better sensitivity than metal and metal oxide NPs because of high surface area and increased electronic charge transfer, have also been reported.

electronics Two-Dimensional Materials for Sensing: Graphene and Beyond

Two-dimensional materials have attracted great scientific attention due to their unusual and fascinating properties for use in electronics, spintronics, photovoltaics, medicine, composites, etc. Graphene, transition metal dichalcogenides such as MoS2, phosphorene, etc., which belong to the family of two-dimensional materials, have shown great promise for gas sensing applications due to their high surface-to-volume ratio, low noise and sensitivity of electronic properties to the changes in the surroundings. Two-dimensional nanostructured semiconducting metal oxide based gas sensors have also been recognized as successful gas detection devices. This review aims to provide the latest advancements in the field of gas sensors based on various two-dimensional materials with the main focus on sensor performance metrics such as sensitivity, specificity, detection limit, response time, and reversibility. Both experimental and theoretical studies on the gas sensing properties of graphene and other two-dimensional materials beyond graphene are also discussed. The article concludes with the current challenges and future prospects for two-dimensional materials in gas sensor applications.

Review Two-Dimensional Materials for Sensing: Graphene and Beyond

2016

Two-Dimensional Materials for Sensing: Graphene and Beyond

Electronics, 2015

Stanene the New Gas Sensing Wonder Material: Current Status and Future Prospects (original) (raw)

Related papers