1
|
Singh S, Varghese AM, Reinalda D, Karanikolos GN. Graphene - based membranes for carbon dioxide separation. J CO2 UTIL 2021. [DOI: 10.1016/j.jcou.2021.101544] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
2
|
Chen J, Ryu GH, Zhang Q, Wen Y, Tai KL, Lu Y, Warner JH. Spatially Controlled Fabrication and Mechanisms of Atomically Thin Nanowell Patterns in Bilayer WS 2 Using in Situ High Temperature Electron Microscopy. ACS NANO 2019; 13:14486-14499. [PMID: 31794193 DOI: 10.1021/acsnano.9b08220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We show controlled production of atomically thin nanowells in bilayer WS2 using an in situ heating holder combined with a focused electron beam in a scanning transmission electron microscope (STEM). We systematically study the formation and evolvement mechanism involved in removing a single layer of WS2 within a bilayer region with 2 nm accuracy in location and without punching through to the other layer to create a hole. Best results are found when using a high temperature of 800 °C, because it enables thermally activated atomic migration and eliminates the interference from surface carbon contamination. We demonstrate precise control over spatial distributions with 5 nm accuracy of patterning and the width of nanowells adjustable by dose-dependent parameters. The mechanism of removing a monolayer of WS2 within a bilayer region is different than removing equivalent sections in a monolayer film due to the van der Waals interaction of the underlying remaining layer in the bilayer system that stabilizes the excess W atom stoichiometry within the edges of the nanowell structure and facilitates expansion. This study offers insights for the nanoengineering of nanowells in two-dimensional (2D) transitional metal dichalcogenides (TMDs), which could hold potential as selective traps to localize 2D reactions in molecules and ions, underpinning the broader utilization of 2D material membranes.
Collapse
Affiliation(s)
- Jun Chen
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Gyeong Hee Ryu
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Qianyang Zhang
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yi Wen
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Kuo-Lun Tai
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Yang Lu
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| | - Jamie H Warner
- Department of Materials , University of Oxford , Parks Road , Oxford OX1 3PH , United Kingdom
| |
Collapse
|
3
|
Roh JS, Choi TH, Lee TH, Yoon HW, Kim J, Kim HW, Park HB. Understanding Gas Transport Behavior through Few-Layer Graphene Oxide Membranes Controlled by Tortuosity and Interlayer Spacing. J Phys Chem Lett 2019; 10:7725-7731. [PMID: 31794229 DOI: 10.1021/acs.jpclett.9b03082] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Here, we elucidate the gas transport behavior through few-layer graphene oxide membranes (FGOMs) that have a systematically controlled diffusion pathway, including tortuosity and channel width. The obtained unusual gas permeation order (especially, CH4 > O2 > N2) of the FGOM provides strong evidence that gas molecules can indeed penetrate through the empty voids created by horizontally assembled GO, which allows selective gas transport features. These unique transport features of the FGOM originate from its continuously connected channel structure, which is an analogue of an ultrapermeable glassy polymer with extremely large free volumes in dense films. Furthermore, variation of the channel width in the range of 0.50-0.55 nm leads to notable changes in the gas permeance orders related to CH4, indicating that there is a transition region for switching the gas transport mechanism between a molecular sieving character and the solution-diffusion model.
Collapse
Affiliation(s)
- Ji Soo Roh
- Department of Energy Engineering , Hanyang University , Seoul 04763 , Korea
| | - Tae Hwan Choi
- Department of Energy Engineering , Hanyang University , Seoul 04763 , Korea
| | - Tae Hoon Lee
- Department of Energy Engineering , Hanyang University , Seoul 04763 , Korea
| | - Hee Wook Yoon
- Department of Energy Engineering , Hanyang University , Seoul 04763 , Korea
| | - Juyoung Kim
- Department of Advanced Materials Engineering , Kangwon National University , Samcheock 25931 , Korea
| | - Hyo Won Kim
- Department of Energy Engineering , Hanyang University , Seoul 04763 , Korea
- Department of Advanced Materials Engineering , Kangwon National University , Samcheock 25931 , Korea
| | - Ho Bum Park
- Department of Energy Engineering , Hanyang University , Seoul 04763 , Korea
| |
Collapse
|
4
|
Graphene-Based Membranes for CO2/CH4 Separation: Key Challenges and Perspectives. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9142784] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Increasing demand to strengthen energy security has increased the importance of natural gas sweetening and biogas upgrading processes. Membrane-based separation of carbon dioxide (CO2) and methane (CH4) is a relatively newer technology, which offers several competitive advantages, such as higher energy-efficiency and cost-effectiveness, over conventional technologies. Recently, the use of graphene-based materials to elevate the performance of polymeric membranes have attracted immense attention. Herein, we do not seek to provide the reader with a comprehensive review of this topic but rather highlight the key challenges and our perspectives going ahead. We approach the topic by evaluating three mainstream membrane designs using graphene-based materials: (1) nanoporous single-layer graphene, (2) few- to multi-layered graphene-based stacked laminates, and (3) mixed-matrix membranes. At present, each design faces different challenges, including low scalability, high production cost, limited performance enhancement, and the lack of robust techno-economic review and systematic membrane design optimization. To help address these challenges, we have mapped out a technology landscape of the current graphene-based membrane research based on the separation performance enhancement, commercial viability, and production cost. Accordingly, we contend that future efforts devoted to advancing graphene-based membranes must be matched by progress in these strategic areas so as to realize practical and commercially relevant graphene-based membranes for CO2/CH4 separation and beyond.
Collapse
|
5
|
White DL, Burkert SC, Hwang SI, Star A. Holey Graphene Metal Nanoparticle Composites via Crystalline Polymer Templated Etching. NANO LETTERS 2019; 19:2824-2831. [PMID: 30958007 DOI: 10.1021/acs.nanolett.8b04755] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
While graphene has sparked enormous research interest since its isolation in 2004, there has also been an interest in developing graphene composite materials that leverage graphene's extraordinary physical properties toward new technologies. Oxidative analogues such as graphene oxide and reduced graphene oxide retain many of the same properties of graphene. While these materials contain many functional moieties, defect formation through current oxidation methods is random which, despite reductive treatments, can never fully recover the properties of the starting material. In the interest of bridging the divide between these two sets of materials for composite materials, here we show a methodology utilizing 2-D covalent organic frameworks as templates for hole formation in graphene through plasma etching. The holes formed act as edge-only chemical handles while retaining a contiguous sp2 structure. Holey graphene structures generated act as autoreduction sites for small noble metal nanoparticles which return many of graphene's original electrical properties that can be used for functional composites. Composite materials here show 103 enhancement of the Raman signal of the underlying holey graphene as well as excellent calculated limits of detection in gas sensing of H2S (3 ppb) and H2 (10 ppm).
Collapse
Affiliation(s)
- David L White
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Seth C Burkert
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Sean I Hwang
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| | - Alexander Star
- Department of Chemistry , University of Pittsburgh , Pittsburgh , Pennsylvania 15260 , United States
| |
Collapse
|
6
|
Segmentation of scanning tunneling microscopy images using variational methods and empirical wavelets. Pattern Anal Appl 2019. [DOI: 10.1007/s10044-019-00824-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
7
|
|
8
|
Three-Dimensional Au/Holey-Graphene as Efficient Electrochemical Interface for Simultaneous Determination of Ascorbic Acid, Dopamine and Uric Acid. MICROMACHINES 2019; 10:mi10020084. [PMID: 30682841 PMCID: PMC6413087 DOI: 10.3390/mi10020084] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 01/18/2019] [Accepted: 01/20/2019] [Indexed: 11/23/2022]
Abstract
The quantification of ascorbic acid (AA), dopamine (DA), and uric acid (UA) has been an important area of research, as these molecules’ determination directly corresponds to the diagnosis and control of diseases of nerve and brain physiology. In our research, graphene oxide (GO) with nano pores deposited with gold nanoparticles were self-assembled to form three-dimensional (3D) Au/holey-graphene oxide (Au/HGO) composite structures. The as-prepared 3DAu/HGO composite structures were characterized for their structures by X-ray diffraction, Raman spectrum, scanning electron microscopy, and transmission electron microscopy coupled with cyclic voltammograms. Finally, the proposed 3DAu/HGO displayed high sensitivity, excellent electron transport properties, and selectivity for the simultaneous electrochemical determination of AA, DA and UA with linear response ranges of 1.0–500 μM, 0.01–50 μM and 0.05–50 μM respectively. This finding paves the way for graphene applications as a biosensor for detecting three analytes in human serum.
Collapse
|
9
|
Polymerization driven monomer passage through monolayer chemical vapour deposition graphene. Nat Commun 2018; 9:4051. [PMID: 30282989 PMCID: PMC6170411 DOI: 10.1038/s41467-018-06599-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 09/14/2018] [Indexed: 01/19/2023] Open
Abstract
Mass transport through graphene is receiving increasing attention due to the potential for molecular sieving. Experimental studies are mostly limited to the translocation of protons, ions, and water molecules, and results for larger molecules through graphene are rare. Here, we perform controlled radical polymerization with surface-anchored self-assembled initiator monolayer in a monomer solution with single-layer graphene separating the initiator from the monomer. We demonstrate that neutral monomers are able to pass through the graphene (via native defects) and increase the graphene defects ratio (Raman ID/IG) from ca. 0.09 to 0.22. The translocations of anionic and cationic monomers through graphene are significantly slower due to chemical interactions of monomers with the graphene defects. Interestingly, if micropatterned initiator-monolayers are used, the translocations of anionic monomers apparently cut the graphene sheet into congruent microscopic structures. The varied interactions between monomers and graphene defects are further investigated by quantum molecular dynamics simulations.
Collapse
|
10
|
Chuah CY, Goh K, Yang Y, Gong H, Li W, Karahan HE, Guiver MD, Wang R, Bae TH. Harnessing Filler Materials for Enhancing Biogas Separation Membranes. Chem Rev 2018; 118:8655-8769. [DOI: 10.1021/acs.chemrev.8b00091] [Citation(s) in RCA: 174] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Chong Yang Chuah
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Kunli Goh
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Yanqin Yang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Heqing Gong
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - Wen Li
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
| | - H. Enis Karahan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| | - Michael D. Guiver
- State Key Laboratory of Engines, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China
| | - Rong Wang
- Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
- School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 649798, Singapore
| | - Tae-Hyun Bae
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459, Singapore
- Singapore Membrane Technology Center, Nanyang Environment and Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore
| |
Collapse
|
11
|
Xin W, Severino J, De Rosa IM, Yu D, Mckay J, Ye P, Yin X, Yang JM, Carlson L, Kodambaka S. One-Step Synthesis of Tunable-Size Gold Nanoplates on Graphene Multilayers. NANO LETTERS 2018; 18:1875-1881. [PMID: 29406754 DOI: 10.1021/acs.nanolett.7b05173] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Au nanoplates (quasi-two-dimensional single crystals) are most commonly synthesized using a mixture of Au precursors via approaches involving multiple processing steps and the use of seed crystals. Here, we report the synthesis of truncated-hexagonal {111}-oriented micrometer-scale Au nanoplates on graphene multilayers using only potassium tetrabromoaurate (KAuBr4) as the precursor. We demonstrate that the nanoplate sizes can be controllably varied from tens of nanometers up to a few micrometers by introducing desired concentrations of chloroauric acid (HAuCl4) to KAuBr4 and their thicknesses from ∼13 to ∼46 nm with the synthesis time. Through a series of experiments carried out as a function of synthesis time and precursor composition [mixtures of HAuCl4 and KAuBr4, KBr, or ionic liquid 1-butyl-3-methylimidazolium bromide ([Bmim]Br)], we identify the optimal HAuCl4 and KAuBr4 concentrations and synthesis times that yield the largest and the thinnest size nanoplates. We show that the nanoplates are kinetically limited morphologies resulting from preferential growth of {111} facets facilitated by bromide ions in KAuBr4 solutions; we suggest that the presence of chloride ions enhances the rate of Au deposition and the relative concentration of chloride and bromide ions determines the shape anisotropy of resulting crystals. Our results provide new insights into the kinetics of nanoplate formation and show that a single precursor containing both Au and Br is sufficient to crystallize nanoplates on graphitic layers, which serve as reducing agent while enabling the nucleation and growth of Au nanoplates. We suggest that a similar approach may be used for the synthesis of nanoplates of other metals on weakly interacting van der Waals layers for, potentially, a variety of new applications.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Xunqian Yin
- School of Materials Science and Engineering , Shandong University of Science and Technology , 579 Qianwangang Road, Economic & Technological Development Zones , Qingdao , Shandong 26650 , China
| | | | | | | |
Collapse
|
12
|
Davaji B, Cho HD, Malakoutian M, Lee JK, Panin G, Kang TW, Lee CH. A patterned single layer graphene resistance temperature sensor. Sci Rep 2017; 7:8811. [PMID: 28821773 PMCID: PMC5562788 DOI: 10.1038/s41598-017-08967-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 07/20/2017] [Indexed: 11/09/2022] Open
Abstract
Micro-fabricated single-layer graphenes (SLGs) on a silicon dioxide (SiO2)/Si substrate, a silicon nitride (SiN) membrane, and a suspended architecture are presented for their use as temperature sensors. These graphene temperature sensors act as resistance temperature detectors, showing a quadratic dependence of resistance on the temperature in a range between 283 K and 303 K. The observed resistance change of the graphene temperature sensors are explained by the temperature dependent electron mobility relationship (~T-4) and electron-phonon scattering. By analyzing the transient response of the SLG temperature sensors on different substrates, it is found that the graphene sensor on the SiN membrane shows the highest sensitivity due to low thermal mass, while the sensor on SiO2/Si reveals the lowest one. Also, the graphene on the SiN membrane reveals not only the fastest response, but also better mechanical stability compared to the suspended graphene sensor. Therefore, the presented results show that the temperature sensors based on SLG with an extremely low thermal mass can be used in various applications requiring high sensitivity and fast operation.
Collapse
Affiliation(s)
- Benyamin Davaji
- Department of Electrical and Computer Engineering, Marquette University, Milwaukee, WI, USA.,School of Electrical and Computer Engineering, Cornell University, Ithaca, NY, USA
| | - Hak Dong Cho
- Department of Physics, Quantum-Functional Semiconductor Research Center, Nano Information Technology Academy, Dongguk University, Seoul, Korea
| | - Mohamadali Malakoutian
- Department of Electrical and Computer Engineering, Marquette University, Milwaukee, WI, USA
| | - Jong-Kwon Lee
- Department of Nanostructure Technology, National Nanofab Center, Daejeon, Korea
| | - Gennady Panin
- Department of Physics, Quantum-Functional Semiconductor Research Center, Nano Information Technology Academy, Dongguk University, Seoul, Korea.,Institute for Microelectronics Technology and High Purity Materials, RAS, 142432, Chernogolovka, Moscow district, Russia
| | - Tae Won Kang
- Department of Physics, Quantum-Functional Semiconductor Research Center, Nano Information Technology Academy, Dongguk University, Seoul, Korea.
| | - Chung Hoon Lee
- Department of Electrical and Computer Engineering, Marquette University, Milwaukee, WI, USA.
| |
Collapse
|
13
|
Wang L, Boutilier MSH, Kidambi PR, Jang D, Hadjiconstantinou NG, Karnik R. Fundamental transport mechanisms, fabrication and potential applications of nanoporous atomically thin membranes. NATURE NANOTECHNOLOGY 2017; 12:509-522. [PMID: 28584292 DOI: 10.1038/nnano.2017.72] [Citation(s) in RCA: 370] [Impact Index Per Article: 52.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 03/20/2017] [Indexed: 05/22/2023]
Abstract
Graphene and other two-dimensional materials offer a new approach to controlling mass transport at the nanoscale. These materials can sustain nanoscale pores in their rigid lattices and due to their minimum possible material thickness, high mechanical strength and chemical robustness, they could be used to address persistent challenges in membrane separations. Here we discuss theoretical and experimental developments in the emerging field of nanoporous atomically thin membranes, focusing on the fundamental mechanisms of gas- and liquid-phase transport, membrane fabrication techniques and advances towards practical application. We highlight potential functional characteristics of the membranes and discuss applications where they are expected to offer advantages. Finally, we outline the major scientific questions and technological challenges that need to be addressed to bridge the gap from theoretical simulations and proof-of-concept experiments to real-world applications.
Collapse
Affiliation(s)
- Luda Wang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Michael S H Boutilier
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Piran R Kidambi
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Doojoon Jang
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Nicolas G Hadjiconstantinou
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | - Rohit Karnik
- Department of Mechanical Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| |
Collapse
|
14
|
Wang S, Li H, Sawada H, Allen CS, Kirkland AI, Grossman JC, Warner JH. Atomic structure and formation mechanism of sub-nanometer pores in 2D monolayer MoS 2. NANOSCALE 2017; 9:6417-6426. [PMID: 28463370 DOI: 10.1039/c7nr01127j] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We use electron-beam nanofabrication to create sub-nanometer (sub-nm) pores in 2D monolayer MoS2 with fine control over the pore size down to 0.6 nm, corresponding to the loss of a single Mo atom and surrounding S atoms. The sub-nm pores are created in situ with 1 nm spatial precision in the MoS2 lattice by control of the angstrom sized probe in an aberration corrected scanning transmission electron microscope with real time tracking of the pore creation. Dynamics of the sub-nm pore creation are captured at the atomic scale and reveal the mechanism of nanopore formation at accelerating voltages of 60 and 80 kV to be due to displacing a Mo atom from the lattice site onto the surface of the MoS2. This process is enabled by the destabilization of the Mo bonding from localized electron beam induced S atom loss. DFT calculations confirm the energetic advantage of having the ejected Mo atom attach on the sheet surface rather than being expelled into vacuum, and indicate sensitivity of the nanopore potential as a function of the adsorption position of the ejected Mo atom. These results provide detailed atomic level insights into the initial process of single Mo loss that underpins the nucleation of a nanopore and explains the formation mechanism of sub-nm pores in MoS2.
Collapse
Affiliation(s)
- Shanshan Wang
- Department of Materials, University of Oxford, Parks Road, Oxford, OX1 3PH, UK.
| | | | | | | | | | | | | |
Collapse
|
15
|
Krishnakumar R, Swathi RS. Tunable Azacrown-Embedded Graphene Nanomeshes for Ion Sensing and Separation. ACS APPLIED MATERIALS & INTERFACES 2017; 9:999-1010. [PMID: 27997113 DOI: 10.1021/acsami.6b10528] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Remarkable selectivity with which crown ethers served as macrocyclic hosts for various guest species has led to numerous investigations on structure-specific interactions. Successful fabrication of graphene nanomeshes has opened up a plethora of avenues for sensing and separation applications. Embedding crown ether backbones in graphene frameworks can therefore be an interesting strategy for exploring the advantages offered by crown ether backbones, yet having the properties of graphene-based materials. Motivated by the recent success in fabrication of crown ether-based graphene nanopores, herein we investigate their performance toward ion sensing and separation using electronic structure methods. The effect of topology and electronic properties of the nanopore are probed by considering a series of oxygen-based and nitrogen-based graphene crown ethers (crown-n; n = 1-6). Our computations have revealed the excellent alkali ion binding properties of azacrown-based graphene nanomeshes over conventional oxygen crown-based graphene nanomeshes and normal crown ethers. Selectivity in ion transmission through the nanomeshes is demonstrated by employing graphene crown ethers [crown-n (n = 4-6)]. To the best of our knowledge, this article is the first report on azacrown-based graphene nanomeshes and their possible applications in ion sensing and separation, an aspect that we hope will be demonstrated in experiments soon.
Collapse
Affiliation(s)
- Rohini Krishnakumar
- School of Chemistry, Indian Institute of Science Education and Research , Thiruvananthapuram, Kerala 695016, India
| | - Rotti Srinivasamurthy Swathi
- School of Chemistry, Indian Institute of Science Education and Research , Thiruvananthapuram, Kerala 695016, India
| |
Collapse
|
16
|
Andrews AM, Liao WS, Weiss PS. Double-Sided Opportunities Using Chemical Lift-Off Lithography. Acc Chem Res 2016; 49:1449-57. [PMID: 27064348 DOI: 10.1021/acs.accounts.6b00034] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We discuss the origins, motivation, invention, development, applications, and future of chemical lift-off lithography, in which a specified pattern of a self-assembled monolayer is removed, i.e., lifted off, using a reactive, patterned stamp that is brought into contact with the monolayer. For Au substrates, this process produces a supported, patterned monolayer of Au on the stamp in addition to the negative pattern in the original molecular monolayer. Both the patterned molecular monolayer on the original substrate and the patterned supported metal monolayer on the stamp are useful as materials and for further applications in sensing and other areas. Chemical lift-off lithography effectively lowers the barriers to and costs of high-resolution, large-area nanopatterning. On the patterned monolayer side, features in the single-nanometer range can be produced across large (square millimeter or larger) areas. Patterns smaller than the original stamp feature sizes can be produced by controlling the degree of contact between the stamp and the lifted-off monolayer. We note that this process is different than conventional lift-off processes in lithography in that chemical lift-off lithography removes material, whereas conventional lift-off is a positive-tone patterning method. Chemical lift-off lithography is in some ways similar to microtransfer printing. Chemical lift-off lithography has critical advantages in the preparation of biocapture surfaces because the molecules left behind are exploited to space and to orient functional(ized) molecules. On the supported metal monolayer side, a new two-dimensional material has been produced. The useful important chemical properties of Au (vis-à-vis functionalization with thiols) are retained, but the electronic and optical properties of bulk Au or even Au nanoparticles are not. These metal monolayers do not quench excitation and may be useful in optical measurements, particularly in combination with selective binding due to attached molecular recognition elements. In contrast to materials such as graphene that have bonding confined to two dimensions, these metal monolayers can be straightforwardly patterned-by patterning the stamp, the initial monolayer, or the initial substrate. Well-developed thiol-Au and related chemistries can be used on the supported monolayers. As there is little quenching and photoabsorption, spectroscopic imaging methods can be used on these functionalized materials. We anticipate that the properties of the metal monolayers can be tuned by varying the chemical, physical, and electronic connections made by and to the supporting molecular layers. That is, the amount of charge in the layer can be determined by controlling the density of S-Au (or other) connections and the molecular backbone and functionality, which determine the strength with which the chemical contact withdraws charge from the metal. This process should work for other coinage-metal substrates and additional systems where the binding of the outermost layers to the substrate is weaker than the molecule-substrate attachment.
Collapse
Affiliation(s)
- Anne M. Andrews
- California
NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, Los
Angeles, California 90095, United States
- Department
of Psychiatry, Hatos Center for Neuropharmacology, and Semel Institute
for Neuroscience and Human Behavior, University of California, Los Angeles, Los
Angeles, California 90095, United States
| | - Wei-Ssu Liao
- Department
of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Paul S. Weiss
- California
NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095, United States
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, Los
Angeles, California 90095, United States
- Department
of Materials Science and Engineering, University of California, Los Angeles, Los
Angeles, California 90095, United States
| |
Collapse
|
17
|
Xu C, He X, Wang C, Chen X, Yuan R, Dai W. Introduction of holes into graphene sheets to further enhance graphene–TiO2 photocatalysis activities. RSC Adv 2016. [DOI: 10.1039/c6ra17603h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Introduction of holes into graphene sheets can more efficiently enhance the photoactivity of semiconductors than that of traditional graphene-involved ones.
Collapse
Affiliation(s)
- Chao Xu
- Research Institute of Photocatalysis
- State Key Laboratory of Photocatalysis on Energy and Environment
- Fuzhou University
- Fuzhou 350002
- P. R. China
| | - Xiaoping He
- Research Institute of Photocatalysis
- State Key Laboratory of Photocatalysis on Energy and Environment
- Fuzhou University
- Fuzhou 350002
- P. R. China
| | - Chen Wang
- Research Institute of Photocatalysis
- State Key Laboratory of Photocatalysis on Energy and Environment
- Fuzhou University
- Fuzhou 350002
- P. R. China
| | - Xun Chen
- Research Institute of Photocatalysis
- State Key Laboratory of Photocatalysis on Energy and Environment
- Fuzhou University
- Fuzhou 350002
- P. R. China
| | - Rusheng Yuan
- Research Institute of Photocatalysis
- State Key Laboratory of Photocatalysis on Energy and Environment
- Fuzhou University
- Fuzhou 350002
- P. R. China
| | - Wenxin Dai
- Research Institute of Photocatalysis
- State Key Laboratory of Photocatalysis on Energy and Environment
- Fuzhou University
- Fuzhou 350002
- P. R. China
| |
Collapse
|
18
|
Eluyemi MS, Eleruja MA, Adedeji AV, Olofinjana B, Fasakin O, Akinwunmi OO, Ilori OO, Famojuro AT, Ayinde SA, Ajayi EOB. Synthesis and Characterization of Graphene Oxide and Reduced Graphene Oxide Thin Films Deposited by Spray Pyrolysis Method. ACTA ACUST UNITED AC 2016. [DOI: 10.4236/graphene.2016.53012] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|