1
|
Yadav S, Gajar B, Aloysius RP, Sahoo S. Interplay between superconducting fluctuations and weak localization in disordered TiN thin films. NANOSCALE 2024. [PMID: 39417772 DOI: 10.1039/d4nr02639j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2024]
Abstract
The interplay between superconducting fluctuations (SFs) and weak localization (WL) has been probed by temperature dependent resistance [R(T)] and magnetoresistance (MR) measurements in two-dimensional disordered superconducting TiN thin films. Within a narrow range of temperature above transition temperature (Tc), the coexistence of SF-mediated positive MR and WL-led negative MR in different ranges of magnetic fields and a crossover from positive MR to negative MR with an increase in temperature are reported herein. The crossover temperature coincides with a characteristic temperature (Tmax) at which a resistance peak appears in the zero-field R(T). The resistance peak and associated magnetoresistance anomalies are addressed using quantum corrections to conductivity (QCC) theory. We show that WL can be accounted for the observed negative MR. By introducing individual coefficients to both SFs and WL contributions, the dominance of one over the other is monitored with respect to temperature. It is observed that just above Tc, SFs dominate; with an increase in temperature, the contributions from both become comparable; and finally, at Tmax, WL takes over completely. The presented approach may be adopted to compare various quantum contributions in two-dimensional superconductors, particularly in the regime where both SFs and WL are pronounced.
Collapse
Affiliation(s)
- Sachin Yadav
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Bikash Gajar
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - R P Aloysius
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| | - Sangeeta Sahoo
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-201002, India
| |
Collapse
|
2
|
Parajuli D. MXenes-polymer nanocomposites for biomedical applications: fundamentals and future perspectives. Front Chem 2024; 12:1400375. [PMID: 38863676 PMCID: PMC11165207 DOI: 10.3389/fchem.2024.1400375] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 04/04/2024] [Indexed: 06/13/2024] Open
Abstract
The article discusses the promising synergy between MXenes and polymers in developing advanced nanocomposites with diverse applications in biomedicine domains. MXenes, possessing exceptional properties, are integrated into polymer matrices through various synthesis and fabrication methods. These nanocomposites find applications in drug delivery, imaging, diagnostics, and environmental remediation. They offer improved therapeutic efficacy and reduced side effects in drug delivery, enhanced sensitivity and specificity in imaging and diagnostics, and effectiveness in water purification and pollutant removal. The perspective also addresses challenges like biocompatibility and toxicity, while suggesting future research directions. In totality, it highlights the transformative potential of MXenes-polymer nanocomposites in addressing critical issues across various fields.
Collapse
Affiliation(s)
- D. Parajuli
- Research Center for Applied Science and Technology, Tribhuvan University, Kathmandu, Nepal
| |
Collapse
|
3
|
Yadav S, Aloysius RP, Gupta G, Sahoo S. Granularity mediated multiple reentrances with negative magnetoresistance in disordered TiN thin films. Sci Rep 2023; 13:22701. [PMID: 38123674 PMCID: PMC10733403 DOI: 10.1038/s41598-023-50091-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023] Open
Abstract
Granular superconductors are the common examples of experimentally accessible model systems which can be used to explore various fascinating quantum phenomena that are fundamentally important and technologically relevant. One such phenomenon is the occurrence of reentrant resistive states in granular superconductors. Here, we report the observation of multiple reentrant resistive states for a disordered TiN thin film in its temperature and magnetic field dependent resistance measurements, R(T) and R(B), respectively. At each of the peak-temperatures corresponding to the zero-field R(T), a resistance peak appears in the R(B) around zero field which leads to a negative magnetoresistance (MR) region in its surrounding. These low-field negative MR regions appear for both perpendicular and parallel field directions with relatively higher amplitude and larger width for the parallel field. By adopting a granularity-based model, we show that the superconducting fluctuations in granular superconductors may lead to the observed reentrant states and the corresponding negative MR. Here, we propose that the reduction in the density of states in the fermionic channel due to the formation of Cooper pairs leads to the reentrant resistive state and the competition between the conduction processes in the single particle and Cooper channels result into the multiple resistive reentrances.
Collapse
Affiliation(s)
- Sachin Yadav
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi, 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - R P Aloysius
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi, 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Govind Gupta
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi, 110012, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Sangeeta Sahoo
- CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi, 110012, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
| |
Collapse
|
4
|
Chinnasamy C, Perumal N, Choubey A, Rajendran S. Recent advancements in MXene-based nanocomposites as photocatalysts for hazardous pollutant degradation - A review. ENVIRONMENTAL RESEARCH 2023; 233:116459. [PMID: 37356535 DOI: 10.1016/j.envres.2023.116459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 06/12/2023] [Accepted: 06/17/2023] [Indexed: 06/27/2023]
Abstract
The recent expeditious industrialization and urbanization showcase the increasing need for renewable and non-renewable energy and the severe environmental crisis. In this regard, numerous 2-dimensional (2D) nanomaterials have been developed as a facile approach to meet the futuristic energy essentials and to resolve the crisis. In contrast, the newly explored 2D MXenes (transition metal carbide/nitrides/carbonitride) have been employed as an intriguing material for various environmental applications. This development is accredited to their unique properties, which include a vast surface area, strong electrical conductivity, fascinating photophysical properties, high mechanical properties, stability in an aqueous medium, high hydrophilicity, biocompatibility, ease of functionalization, and excellent thermal properties. MXenes act as a potential candidate in water desalination, energy storage devices such as electrodes of Li-ion batteries and pseudo capacitors, hydrogen production, sensors, and wastewater treatment. This review article deliberates the synthesis of MXene and nanocomposites of MXene and their photo-catalytic actions against various toxic pollutants such as organic dyes and heavy metals in wastewater. This review also precises the various preparation methods of MXene-based photocatalyst and the enhanced photocatalytic activity of MXene and MXene-based nanocomposites in wastewater treatment. Also, it details the attempts made to improve the photocatalytic activity of MXene-based nanocomposites in terms of their structural compositions. In addition, the merits and demerits of the MXene-based photocatalysts are deliberated, which may pave the way for future research in this arena.
Collapse
Affiliation(s)
- Chandraleka Chinnasamy
- Department of Physics, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603 110, India
| | - Nagapandiselvi Perumal
- Department of Physics, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603 110, India.
| | - Akanksha Choubey
- Department of Physics, Sri Sivasubramaniya Nadar College of Engineering, Chennai, 603 110, India
| | - Saravanan Rajendran
- Instituto de Alta Investigación, Universidad de Tarapacá, Arica, 1000000, Chile.
| |
Collapse
|
5
|
Sumaiya SA, Demiroglu I, Caylan OR, Buke GC, Sevik C, Baykara MZ. Atomically Resolved Defects on Thin Molybdenum Carbide (α-Mo 2C) Crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023. [PMID: 37494546 DOI: 10.1021/acs.langmuir.3c00674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Thin transition metal carbides (TMCs) garnered significant attention in recent years due to their attractive combination of mechanical and electrical properties with chemical and thermal stability. On the other hand, a complete picture of how defects affect the physical properties and application potential of this emerging class of materials is lacking. Here, we present an atomic-resolution study of defects on thin crystals of molybdenum carbide (α-Mo2C) grown via chemical vapor deposition (CVD) by way of conductive atomic force microscopy (C-AFM) measurements under ambient conditions. Defects are characterized based on the type (enhancement/attenuation) and spatial extent (compact/extended) of the effect they have on the conductivity landscape of the crystal surfaces. Ab initio calculations performed by way of density functional theory (DFT) are employed to gather clues about the identity of the defects.
Collapse
Affiliation(s)
- Saima A Sumaiya
- Department of Mechanical Engineering, University of California Merced, Merced, California 95343, United States
| | - Ilker Demiroglu
- Department of Mechanical Engineering, Eskisehir Technical University, Eskisehir 26555, Turkey
| | - Omer R Caylan
- Department of Materials Science and Nanotechnology Engineering, Micro and Nanotechnology Graduate Program, TOBB University of Economics and Technology, Ankara 06560, Turkey
| | - Goknur Cambaz Buke
- Department of Materials Science and Nanotechnology Engineering, Micro and Nanotechnology Graduate Program, TOBB University of Economics and Technology, Ankara 06560, Turkey
| | - Cem Sevik
- Department of Mechanical Engineering, Eskisehir Technical University, Eskisehir 26555, Turkey
| | - Mehmet Z Baykara
- Department of Mechanical Engineering, University of California Merced, Merced, California 95343, United States
| |
Collapse
|
6
|
Khosla A, Sonu, Awan HTA, Singh K, Gaurav, Walvekar R, Zhao Z, Kaushik A, Khalid M, Chaudhary V. Emergence of MXene and MXene-Polymer Hybrid Membranes as Future- Environmental Remediation Strategies. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203527. [PMID: 36316226 PMCID: PMC9798995 DOI: 10.1002/advs.202203527] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 09/20/2022] [Indexed: 07/26/2023]
Abstract
The continuous deterioration of the environment due to extensive industrialization and urbanization has raised the requirement to devise high-performance environmental remediation technologies. Membrane technologies, primarily based on conventional polymers, are the most commercialized air, water, solid, and radiation-based environmental remediation strategies. Low stability at high temperatures, swelling in organic contaminants, and poor selectivity are the fundamental issues associated with polymeric membranes restricting their scalable viability. Polymer-metal-carbides and nitrides (MXenes) hybrid membranes possess remarkable physicochemical attributes, including strong mechanical endurance, high mechanical flexibility, superior adsorptive behavior, and selective permeability, due to multi-interactions between polymers and MXene's surface functionalities. This review articulates the state-of-the-art MXene-polymer hybrid membranes, emphasizing its fabrication routes, enhanced physicochemical properties, and improved adsorptive behavior. It comprehensively summarizes the utilization of MXene-polymer hybrid membranes for environmental remediation applications, including water purification, desalination, ion-separation, gas separation and detection, containment adsorption, and electromagnetic and nuclear radiation shielding. Furthermore, the review highlights the associated bottlenecks of MXene-Polymer hybrid-membranes and its possible alternate solutions to meet industrial requirements. Discussed are opportunities and prospects related to MXene-polymer membrane to devise intelligent and next-generation environmental remediation strategies with the integration of modern age technologies of internet-of-things, artificial intelligence, machine-learning, 5G-communication and cloud-computing are elucidated.
Collapse
Affiliation(s)
- Ajit Khosla
- Department of Applied ChemistrySchool of Advanced Materials and NanotechnologyXidian UniversityXi'an710126P. R. China
| | - Sonu
- School Advanced of Chemical SciencesShoolini University of Biotechnology and Management SciencesBajholSolanHP173212India
| | - Hafiz Taimoor Ahmed Awan
- Graphene and Advanced 2D Materials Research Group (GAMRG)School of Engineering and TechnologySunway UniversityNo. 5Jalan UniversityBandar SunwayPetaling JayaSelangor47500Malaysia
| | - Karambir Singh
- School of Physics and Material scienceShoolini University of Biotechnology and Management SciencesBajholSolanHP173212India
| | - Gaurav
- Department of BotanyRamjas CollegeUniversity of DelhiDelhi110007India
- SUMAN Laboratory (SUstainable Materials and Advanced Nanotechnology Lab)University of DelhiNew Delhi110072India
| | - Rashmi Walvekar
- Department of Chemical EngineeringSchool of New Energy and Chemical EngineeringXiamen University MalaysiaJalan Sunsuria, Bandar SunsuriaSepangSelangor43900Malaysia
| | - Zhenhuan Zhao
- Department of Applied ChemistrySchool of Advanced Materials and NanotechnologyXidian UniversityXi'an710126P. R. China
| | - Ajeet Kaushik
- NanoBioTech LaboratoryHealth System EngineeringDepartment of Environmental EngineeringFlorida Polytechnic UniversityLakelandFL33805USA
- School of EngineeringUniversity of Petroleum and Energy Studies (UPES)DehradunUttarakhand248007India
| | - Mohammad Khalid
- Graphene and Advanced 2D Materials Research Group (GAMRG)School of Engineering and TechnologySunway UniversityNo. 5Jalan UniversityBandar SunwayPetaling JayaSelangor47500Malaysia
- Sunway Materials Smart Science and Engineering (SMS2E) Research ClusterSunway UniversityNo. 5Jalan UniversitiBandar SunwayPetaling JayaSelangor47500Malaysia
| | - Vishal Chaudhary
- Research Cell and Department of PhysicsBhagini Nivedita CollegeUniversity of DelhiNew DelhiIndia
- SUMAN Laboratory (SUstainable Materials and Advanced Nanotechnology Lab)University of DelhiNew Delhi110072India
| |
Collapse
|
7
|
Zhang Y, Wang Y, Guo C, Wang Y. Molybdenum Carbide-Based Photocatalysts: Synthesis, Functionalization, and Applications. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:12739-12756. [PMID: 36245364 DOI: 10.1021/acs.langmuir.2c01887] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
As an effective non-noble, molybdenum carbide (MoxC: MoC or Mo2C) has attracted extensive attention and is regarded as a promising research area in the near future owing to its good biocompatibility, high stability, band gap adjustability, rich valence states, and excellent catalytic activity. This Perspective summarizes the recent progress and achievements for the molybdenum carbide-based catalysts. First, the crystal and band structures of molybdenum carbides are generally presented. Second, various modifying strategies for molybdenum carbides are outlined to enhance the photocatalytic performance, including doping engineering, vacancy engineering, morphology and structure engineering, and the establishment of molybdenum carbide-based composite catalysts. Finally, potential applications in the photocatalysis area of molybdenum carbide-based photocatalyst are generalized. Future development trends and perspective for this promising material are also discussed.
Collapse
Affiliation(s)
- Yifan Zhang
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, P. R. China
| | - Yan Wang
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, P. R. China
| | - Chaofei Guo
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, P. R. China
| | - Yong Wang
- School of Environmental and Chemical Engineering, Shanghai University, 99 Shangda Road, Shanghai 200444, P. R. China
| |
Collapse
|
8
|
Xiao S, Zheng Y, Wu X, Zhou M, Rong X, Wang L, Tang Y, Liu X, Qiu L, Cheng C. Tunable Structured MXenes With Modulated Atomic Environments: A Powerful New Platform for Electrocatalytic Energy Conversion. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2203281. [PMID: 35989101 DOI: 10.1002/smll.202203281] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Owing to their rich surface chemistry, high conductivity, tunable bandgap, and thermal stability, structured 2D transition-metal carbides, nitrides, and carbonitrides (MXenes) with modulated atomic environments have emerged as efficient electrochemical energy conversion systems in the past decade. Herein, the most recent advances in the engineering of tunable structured MXenes as a powerful new platform for electrocatalytic energy conversion are comprehensively summarized. First, the state-of-the-art synthetic and processing methods, tunable nanostructures, electronic properties, and modulation principles of engineering MXene-derived nanoarchitectures are focused on. The current breakthroughs in the design of catalytic centers, atomic environments, and the corresponding structure-performance correlations, including termination engineering, heteroatom doping, defect engineering, heterojunctions, and alloying, are discussed. Furthermore, representative electrocatalytic applications of structured MXenes in energy conversion systems are also summarized. Finally, the challenges in and prospects for constructing MXene-based electrocatalytic materials are also discussed. This review provides a leading-edge understanding of the engineering of various MXene-based electrocatalysts and offers theoretical and experimental guidance for prospective studies, thereby promoting the practical applications of tunable structured MXenes in electrocatalytic energy conversion systems.
Collapse
Affiliation(s)
- Sutong Xiao
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
| | - Yijuan Zheng
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
- State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Xizheng Wu
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
- State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Mi Zhou
- College of Biomass Science and Engineering, Sichuan University, Chengdu, 610065, China
| | - Xiao Rong
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
| | - Liyun Wang
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
| | - Yuanjiao Tang
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
| | - Xikui Liu
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
- State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
| | - Li Qiu
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
| | - Chong Cheng
- College of Polymer Science and Engineering, Department of Ultrasound, West China Hospital, Sichuan University, Chengdu, 610065, China
- State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China
- Med-X Center for Materials, Sichuan University, Chengdu, 610041, China
| |
Collapse
|
9
|
Wang B, Zhao C, Wang C, Li R, Zhang G, Mu R, Fu Q. Low-temperature growth of ultrathin and epitaxial Mo 2C nanosheets via a vapor-liquid-solid process. NANOSCALE 2022; 14:9142-9149. [PMID: 35723539 DOI: 10.1039/d2nr02389j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Due to the unique physical and chemical properties, transition metal carbides (TMCs) have many potential applications in the fields of energy conversion and catalysis. Chemical vapor deposition (CVD) is a promising method to synthesize TMCs. However, spatially inhomogeneous supply of transition metal precursor vapor in the normal CVD process generally leads to poor control of the morphology and uniformity of the products. Here, we report a vapor-liquid-solid (VLS) growth process where non-volatile Na2MoO4 is used to act as a liquid precursor for the growth of uniform ultrathin Mo2C nanosheets on Al2O3(0001). The morphology of the nanosheets can be controlled by tuning the precursor concentration, annealing time and growth temperature. The roles of Na and the liquid-solid interface in consolidating Mo atoms and promoting the epitaxial growth of Mo2C nanosheets are demonstrated. Furthermore, we show that the liquid-solid interface can cause the crystalline phase transition of Mo2C nanosheets through verification experiments.
Collapse
Affiliation(s)
- Bin Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
- College of Chemistry and Materials Engineering, Bohai University, Jinzhou, 121013, China
| | - Changbao Zhao
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Chao Wang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Rongtan Li
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Guohui Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Rentao Mu
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| | - Qiang Fu
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
| |
Collapse
|
10
|
Review on MXenes-based nanomaterials for sustainable opportunities in energy storage, sensing and electrocatalytic reactions. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
|
11
|
Zhou H, Chen Z, Kountoupi E, Tsoukalou A, Abdala PM, Florian P, Fedorov A, Müller CR. Two-dimensional molybdenum carbide 2D-Mo 2C as a superior catalyst for CO 2 hydrogenation. Nat Commun 2021; 12:5510. [PMID: 34535647 PMCID: PMC8448824 DOI: 10.1038/s41467-021-25784-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/26/2021] [Indexed: 11/16/2022] Open
Abstract
Early transitional metal carbides are promising catalysts for hydrogenation of CO2. Here, a two-dimensional (2D) multilayered 2D-Mo2C material is prepared from Mo2CTx of the MXene family. Surface termination groups Tx (O, OH, and F) are reductively de-functionalized in Mo2CTx (500 °C, pure H2) avoiding the formation of a 3D carbide structure. CO2 hydrogenation studies show that the activity and product selectivity (CO, CH4, C2–C5 alkanes, methanol, and dimethyl ether) of Mo2CTx and 2D-Mo2C are controlled by the surface coverage of Tx groups that are tunable by the H2 pretreatment conditions. 2D-Mo2C contains no Tx groups and outperforms Mo2CTx, β-Mo2C, or the industrial Cu-ZnO-Al2O3 catalyst in CO2 hydrogenation (evaluated by CO weight time yield at 430 °C and 1 bar). We show that the lack of surface termination groups drives the selectivity and activity of Mo-terminated carbidic surfaces in CO2 hydrogenation. The development of robust and efficient catalysts for CO2 hydrogenation to value-added chemicals is an urgent task. Here the authors report two-dimensional carbide catalyst based on earth-abundant molybdenum that hydrogenates CO2 with high activity, stable performance and tunable selectivity.
Collapse
Affiliation(s)
- Hui Zhou
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland.,Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China
| | - Zixuan Chen
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland
| | - Evgenia Kountoupi
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland
| | - Athanasia Tsoukalou
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland
| | - Paula M Abdala
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland
| | - Pierre Florian
- CNRS, CEMHTI UPR3079, Université d'Orléans, F-45071, Orléans, France
| | - Alexey Fedorov
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland.
| | - Christoph R Müller
- Department of Mechanical and Process Engineering, ETH Zürich, CH 8092, Zürich, Switzerland.
| |
Collapse
|
12
|
Liu S, Shang S, Lv R, Wang Y, Wang J, Ren W, Wang Y. Molybdenum Carbide Buried in D-Shaped Fibers as a Novel Saturable Absorber Device for Ultrafast Photonics Applications. ACS APPLIED MATERIALS & INTERFACES 2021; 13:19128-19137. [PMID: 33847490 DOI: 10.1021/acsami.1c01345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Study of nonlinear laser-matter interactions in 2D materials has promoted development of photonics applications. As a typical MXene material, molybdenum carbide (Mo2C) has attracted much attention because of its graphene-like structure. Here, a type of D-shaped fiber (DF)-buried Mo2C saturable absorber (SA) fabricated by magnetron-sputtering deposition (MSD) and sol-gel technique is reported. The Mo2C material was buried between the bottom DF and the upper amorphous silica fabricated by sol-gel technology. Therefore, the DF-based SA effectively solves the problem of material shedding and aging, thus improving the stability and damage threshold of the fiber laser. Application of the SA in erbium-doped fiber laser and stable passive Q-switched operation with a maximum pulse energy of 430.47 nJ is realized. By adjusting the polarization state and pump power, high-power mode-locked pulses are generated with a pulse duration and output power of 199 fs and 54.13 mW, respectively. Further, bound-state soliton pulses are obtained with a pulse width of 312 fs and soliton interval of 1.26 ps for the first time based on MXene materials. Moreover, by application of the SA in ytterbium-doped fiber lasers, a stable dissipative soliton mode-locked pulse is obtained with a pulse width of 23 ps. These results indicate that the DF-based buried Mo2C as a novel SA provides a reliable method for all-fiber and multifunctional high-power ultrafast laser.
Collapse
Affiliation(s)
- Sicong Liu
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Shiguang Shang
- School of Science, Xi'an Institute of Posts and Telecommunications, Xi'an 710121, China
| | - Ruidong Lv
- School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yonggang Wang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China
| | - Jiang Wang
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Wei Ren
- School of Science, Xi'an Institute of Posts and Telecommunications, Xi'an 710121, China
| | - Yishan Wang
- State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119, China
| |
Collapse
|
13
|
Zhang J, Cao Z, He X, Liu W, Wen Y, Cavallo L, Ren W, Cheng H, Zhang X. Superconductivity and High-Pressure Performance of 2D Mo 2C Crystals. J Phys Chem Lett 2021; 12:2219-2225. [PMID: 33635673 DOI: 10.1021/acs.jpclett.1c00071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Two-dimensional (2D) materials have attracted significant attention for their ability to support novel magneto-electrical transport and their optical and magnetic properties, of which their superconductivity is particularly of interest. Here we report on the behavior of superconductivity in 2D Mo2C crystals when hydrostatic pressure is applied, which has not yet been described in the literature. We found that the localization of boundary atoms disorder-induced Cooper pairs can suppress the superconducting transition temperature (Tc) as effectively as a magnetic field and current. We observed that the Tc initially decreased as the pressure increased to 1.75 GPa but then began to increase as the pressure increased further to 2.5 GPa. Our density functional theory calculations revealed that this behavior was linked to the modulation of the strength of the electron-phonon coupling and the electron property, which was triggered by compression of the lattice under high pressure. We attributed the inflection point in the hydrostatic pressure-dependent Tc curve to the structural phase transition of Mo2C from a hexagonal to an orthorhombic structure. This work presents a new avenue for the study of the superconductivity of Mo2C, which can be extended to apply to other 2D superconductors to modulate their electronic states.
Collapse
Affiliation(s)
- Junli Zhang
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
- Key Laboratory of Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
| | - Zhen Cao
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Xin He
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Wenhao Liu
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Yan Wen
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Luigi Cavallo
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Huiming Cheng
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
| | - Xixiang Zhang
- Division of Physical Science and Engineering (PSE), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
14
|
Xu C, Liu Z, Zhang Z, Liu Z, Li J, Pan M, Kang N, Cheng HM, Ren W. Superhigh Uniform Magnetic Cr Substitution in a 2D Mo 2 C Superconductor for a Macroscopic-Scale Kondo Effect. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2002825. [PMID: 32776372 DOI: 10.1002/adma.202002825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 06/27/2020] [Indexed: 06/11/2023]
Abstract
Substitutional doping provides an effective strategy to tailor the properties of 2D materials, but it remains an open challenge to achieve tunable uniform doping, especially at high doping level. Here, uniform lattice substitution of a 2D Mo2 C superconductor by magnetic Cr atoms with controlled concentration up to ≈46.9 at% by chemical vapor deposition and a specifically designed Cu/Cr/Mo trilayer growth substrate is reported. The concentration of Cr atoms can be easily tuned by simply changing the thickness of the Cr layer, and the samples retain the original structure of 2D Mo2 C even at a very high Cr concentration. The controlled uniform Cr doping enables the tuning of the competition of the 2D superconductor and the Kondo effect across the whole sample. Transport measurements show that with increasing Cr concentration, the superconductivity of the 2D Cr-doped Mo2 C crystals disappears along with the emergence of the Kondo effect, and the Kondo temperature increases monotonously. Using scanning tunneling microscopy/spectroscopy, the mechanism of the doping level effect on the interplay and evolution between superconductivity and the Kondo effect is revealed. This work paves a new way for the synthesis of 2D materials with widely tunable doping levels, and provides new understandings on the interplay between superconductivity and magnetism in the 2D limit.
Collapse
Affiliation(s)
- Chuan Xu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
| | - Zhen Liu
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing, 100871, P. R. China
| | - Zongyuan Zhang
- School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
- Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education Institutes of Physical Science and Information Technology, Anhui University, Hefei, 230601, China
| | - Zhibo Liu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
| | - Jingyin Li
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing, 100871, P. R. China
| | - Minghu Pan
- School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, P. R. China
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119, China
| | - Ning Kang
- Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics, Peking University, Beijing, 100871, P. R. China
| | - Hui-Ming Cheng
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
- School of Materials Science and Engineering, University of Science and Technology of China, Shenyang, 110016, P. R. China
- Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, P. R. China
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, P. R. China
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an, 710119, China
| |
Collapse
|
15
|
Bekaert J, Sevik C, Milošević MV. First-principles exploration of superconductivity in MXenes. NANOSCALE 2020; 12:17354-17361. [PMID: 32789416 DOI: 10.1039/d0nr03875j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
MXenes are an emerging class of two-dimensional materials, which in their thinnest limit consist of a monolayer of carbon or nitrogen (X) sandwiched between two transition metal (M) layers. We have systematically searched for superconductivity among MXenes for a range of transition metal elements, based on a full first-principles characterization in combination with the Eliashberg formalism. Thus, we identified six superconducting MXenes: three carbides (Mo2C, W2C and Sc2C) and three nitrides (Mo2N, W2N and Ta2N). The highest critical temperature of ∼16 K is found in Mo2N, for which a successful synthesis method has been established [Urbankowski et al., Nanoscale, 2017, 9, 17722-17730]. Moreover, W2N presents a novel case of competing superconducting and charge density wave phases.
Collapse
Affiliation(s)
- Jonas Bekaert
- Department of Physics & NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
| | - Cem Sevik
- Department of Mechanical Engineering, Faculty of Engineering, Eskisehir Technical University, 26555 Eskisehir, Turkey
| | - Milorad V Milošević
- Department of Physics & NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium.
| |
Collapse
|
16
|
Yang L, Chen W, Yang R, Chen A, Zhang H, Sun Y, Jia Y, Li X, Tang Z, Gui X. Fabrication of MoO x/Mo 2C-Layered Hybrid Structures by Direct Thermal Oxidation of Mo 2C. ACS APPLIED MATERIALS & INTERFACES 2020; 12:10755-10762. [PMID: 32031373 DOI: 10.1021/acsami.9b18650] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two-dimensional (2D) Mo2C, as a new member of transition metal carbides, has many intriguing properties and potential applications in superconductors and electronic devices. The thermal stability of 2D materials is essential for the performance of the related devices, especially the ones with a vertical heterostructure. However, rare reports have demonstrated the thermal stability of Mo2C and the effects of thermal stability on its performance. Here, we propose a facile and controllable method to directly oxidize Mo2C to MoOx, forming a MoOx/Mo2C heterostructure. During the oxidization process, an in situ technique is employed to uncover the transformation and thermal stability of the Mo2C. The chemical vapor deposition Mo2C shows high structural stability below 550 °C in Ar or below 350 °C in O2, which demonstrates the high thermal stability and antioxidation of the Mo2C film. The metallic Mo2C is gradually oxidized to semiconducting MoOx as the temperature increases above 350 °C. The oxidization rate can be easily controlled by adjusting the oxidation temperature and time. Further, the obtained MoOx/Mo2C vertical hybrid structure shows obvious Schottky junction behaviors, strongly indicating the perfect interfacial contact between the component layers. This work offers a new strategy for the controllable fabrication of high-quality 2D heterostructures.
Collapse
Affiliation(s)
- Leilei Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenjun Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Rongliang Yang
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Anqi Chen
- College of Innovation and Entrepreneurship, Southern University of Science and Technology, Shenzhen 518055, China
| | - Hao Zhang
- Instrumental Analysis and Research Center (IARC), Sun Yat-sen University, Guangzhou 510275, China
| | - Yibo Sun
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Yufei Jia
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Xinming Li
- Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices, School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006 China
| | - Zikang Tang
- Institute of Applied Physics and Materials Engineering, University of Macau, Avenida da Universidade, Taipa 999078, Macau, China
| | - Xuchun Gui
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| |
Collapse
|
17
|
Zha XH, Xu P, Huang Q, Du S, Zhang RQ. Mo 2B, an MBene member with high electrical and thermal conductivities, and satisfactory performances in lithium ion batteries. NANOSCALE ADVANCES 2020; 2:347-355. [PMID: 36133999 PMCID: PMC9417839 DOI: 10.1039/c9na00610a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 11/12/2019] [Indexed: 06/13/2023]
Abstract
Owing to their high specific area, good flexibility and many other unique properties, two-dimensional (2D) materials have attracted extensive attention in the recent two decades. As an analogy to the well-studied MXenes, MBenes also emerged. In this work, Mo2B, an MBene member, is predicted both in H- and T-type configurations from first-principles calculations. Structural, mechanical, electronic, and thermal properties, and performances in lithium ion batteries (LIBs) for both configurations are investigated. The H-type Mo2B is found to be the stable structure, which can be transformed into the T-type by applying strains. The elastic constants c 11 in the H- and T-type Mo2B are respectively calculated to be 187.5 and 157.6 N m-1, which are higher than that in the previously reported Mo2C. The electronic thermal conductivity and electrical conductivity are investigated based on the semiclassical Boltzmann transport theory. The electrical conductivities for both structures are of the order of 106 Ω-1 m-1. Because of the large phonon contributions, the thermal conductivities in the H- and T-type Mo2B are much higher than that of the synthesized Mo2C. Based on a 5 μm flake length, the phonon thermal conductivities at room temperature are calculated to be 146 and 141 W m-1 K-1 respectively for the H- and T-type configurations. The T-type Mo2B shows promising performances in LIBs. The theoretical volumetric capacity is as high as 2424 mA h cm-3, and the migration energy barrier is as low as 0.0372 eV. These data imply that Mo2B has widespread applications, such as in conductive films and anode materials.
Collapse
Affiliation(s)
- Xian-Hu Zha
- Center for Quantum Computing, Peng Cheng Laboratory Shenzhen 518055 China
| | - Pengxiang Xu
- Center for Quantum Computing, Peng Cheng Laboratory Shenzhen 518055 China
| | - Qing Huang
- Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang 315201 China
| | - Shiyu Du
- Engineering Laboratory of Advanced Energy Materials, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences Ningbo Zhejiang 315201 China
| | - Rui-Qin Zhang
- Department of Physics, City University of Hong Kong Hong Kong SAR China
| |
Collapse
|
18
|
Li L, Gao M, Baltrusaitis J, Shi D. The shape-dependent surface oxidation of 2D ultrathin Mo 2C crystals. NANOSCALE ADVANCES 2019; 1:4692-4696. [PMID: 36133110 PMCID: PMC9419211 DOI: 10.1039/c9na00504h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 11/08/2019] [Indexed: 06/16/2023]
Abstract
2D atomic crystals have been widely explored, usually owing to their numerous shapes, of which the typical hexagon has drawn the most interest. However, the relationship between shape and properties has not been fully probed, owing to the lack of a proper system. Here, we demonstrate for the first time the shape-dependent surface oxidation of 2D Mo2C crystals, where the elongated flakes are preferentially oxidized under ambient conditions when compared with regular ones, showing higher chemical activity. The gradual surface oxidation of elongated Mo2C crystals as a function of time is clearly observable. Structural determinations reveal that a discrepancy in the arrangement of Mo and C atoms between elongated and regular crystals accounts for the selective oxidation behavior. The identification of the shape-dependent surface oxidization of Mo2C crystals provides significant possibilities for tuning the properties of 2D materials via shape-control.
Collapse
Affiliation(s)
- Lin Li
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China Chengdu 610054 P. R. China
| | - Min Gao
- School of Electronic Science and Engineering, University of Electronic Science and Technology of China Chengdu 610054 China
| | - Jonas Baltrusaitis
- Department of Chemical and Biomolecular Engineering, Lehigh University 111 Research drive Bethlehem PA 18015 USA
| | - Dong Shi
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China Chengdu 610054 P. R. China
| |
Collapse
|
19
|
Sun W, Wang X, Feng J, Li T, Huan Y, Qiao J, He L, Ma D. Controlled synthesis of 2D Mo 2C/graphene heterostructure on liquid Au substrates as enhanced electrocatalytic electrodes. NANOTECHNOLOGY 2019; 30:385601. [PMID: 31234161 DOI: 10.1088/1361-6528/ab2c0d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
2D Mo2C has drawn considerable interest recently for its excellent properties in 2D superconductivity and enhanced hydrogen evolution reaction (HER). Liquid metals have been demonstrated to be an ideal substrate for large-area 2D Mo2C growth. However, the growth mechanism of 2D Mo2C on liquid metals has rarely been explored. Here we report the synthesis of high-quality 2D Mo2C crystals and Mo2C/graphene heterostructures on liquid Au by chemical vapor deposition method. A sunk growth mode of 2D Mo2C on liquid Au substrates has revealed, by atomic force microscope characterizations, that some Mo2C crystals grow below the level of Au terraces around tens of nanometers. Furthermore, graphene/Mo2C heterostructure is controllably synthesized by tuning the hydrogen/carbon ratio, which is proven to be an enhanced electrocatalyst for HER against pure Mo2C crystal grown on liquid Au substrates.
Collapse
Affiliation(s)
- Wenyu Sun
- Department of Physics, Capital Normal University, Beijing, 100048, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Zhang Z, Gedeon H, Cheng Z, Xu C, Shao Z, Sun H, Li S, Cao Y, Zhang X, Bian Q, Liu L, Liu Z, Cheng HM, Ren W, Pan M. Layer-Stacking, Defects, and Robust Superconductivity on the Mo-Terminated Surface of Ultrathin Mo 2C Flakes Grown by CVD. NANO LETTERS 2019; 19:3327-3335. [PMID: 30995413 DOI: 10.1021/acs.nanolett.9b00972] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Materials can exhibit exotic properties when they approach the two-dimensional (2D) limit. Because of promising applications in catalysis and energy storage, 2D transition-metal carbides (TMCs) have attracted considerable attention in recent years. Among these TMCs, ultrathin crystalline α-Mo2C flakes have been fabricated by chemical vapor deposition on Cu/Mo bilayer foils, and their 2D superconducting property was revealed by transport measurements. Herein, we studied the ultrathin α-Mo2C flakes by atomic-resolved scanning tunneling microscopy/spectroscopy (STM/S). Strain-related structural modulation and the coexistence of different layer-stacking modes are observed on the Mo-terminated surface of α-Mo2C flakes as well as various lattice defects. Furthermore, an enhanced superconductivity with shorter correlation length was observed by STS technique, and such superconductivity is very robust despite the appearance of the defects. A mechanism of superconducting enhancement is proposed based on the strain-induced strong coupling and the increased disordering originated from lattice defects. Our results provide a comprehensive understanding of the correlations between atomic structure, defects, and enhanced superconductivity of this emerging 2D material.
Collapse
Affiliation(s)
- Zongyuan Zhang
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Habakubaho Gedeon
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Zhengwang Cheng
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Chuan Xu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110016 , P.R. China
| | - Zhibin Shao
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Haigen Sun
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Shaojian Li
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Yan Cao
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Xin Zhang
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Qi Bian
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Lijun Liu
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| | - Zhibo Liu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110016 , P.R. China
| | - Hui-Ming Cheng
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110016 , P.R. China
- School of Material Science and Engineering , University of Science and Technology of China , Shenyang 110016 , P.R. China
- Tsinghua-Berkeley Shenzhen Institute (TBSI) , Tsinghua University , 1001 Xueyuan Road , Shenzhen 518055 , P.R. China
| | - Wencai Ren
- Shenyang National Laboratory for Materials Science, Institute of Metal Research , Chinese Academy of Sciences , Shenyang 110016 , P.R. China
- School of Material Science and Engineering , University of Science and Technology of China , Shenyang 110016 , P.R. China
| | - Minghu Pan
- School of Physics , Huazhong University of Science and Technology , Wuhan 430074 , P.R. China
| |
Collapse
|
21
|
Chaitoglou S, Giannakopoulou T, Speliotis T, Vavouliotis A, Trapalis C, Dimoulas A. Mo 2C/graphene heterostructures: low temperature chemical vapor deposition on liquid bimetallic Sn-Cu and hydrogen evolution reaction electrocatalytic properties. NANOTECHNOLOGY 2019; 30:125401. [PMID: 30566921 DOI: 10.1088/1361-6528/aaf9e8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thin 2D Mo2C/graphene vertical heterostructures have attracted significant attention due to their potential application as electrodes in the hydrogen evolution reaction (HER) and energy storage. A common drawback in the chemical vapor deposition synthesis of these structures is the demand for high temperature growth, which should be higher than the melting temperature of the metal catalyst. The most common metallic catalyst is Cu, which has a melting temperature of 1084 °C. Here, we report the growth of thin, ∼200 nm in thickness, semitransparent micrometer-sized Mo2C domains and Mo2C/graphene heterostructures at lower temperatures using liquid Sn-Cu alloys. No Sn-associated defects are observed, making the alloy an appealing growth substrate. Raman spectroscopy reveals the vertical interaction between graphene and Mo2C, as shown by the variation in the strain of the graphene film. The results demonstrate the capability to grow continuous nanometer-thin Mo2C films at temperatures as low as 880 °C, without sacrificing the growth rate. Mo2C films are proven to be efficient electrocatalysts for the HER. Moreover, we demonstrate the beneficial role of graphene overgrown on Mo2C in reducing the HER overpotential values, which is attributed to more efficient charge transfer kinetics, compared to pure Mo2C films.
Collapse
Affiliation(s)
- Stefanos Chaitoglou
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research 'DEMOKRITOS', 15310, Athens, Greece
| | | | | | | | | | | |
Collapse
|
22
|
Chen W, Gui X, Yang L, Zhu H, Tang Z. Wrinkling of two-dimensional materials: methods, properties and applications. NANOSCALE HORIZONS 2019; 4:291-320. [PMID: 32254086 DOI: 10.1039/c8nh00112j] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Recently, two-dimensional (2D) materials, including graphene, its derivatives, metal films, MXenes and transition metal dichalcogenides (TMDs), have been widely studied because of their tunable electronic structures and special electrical and optical properties. However, during the fabrication of these 2D materials with atomic thickness, formation of wrinkles or folds is unavoidable to enable their stable existence. Meaningfully, it is found that wrinkled structures simultaneously impose positive changes on the 2D materials. Specifically, the architecture of wrinkled structures in 2D materials additionally induces excellent properties, which are of great importance for their practical applications. In this review, we provide an overview of categories of 2D materials, which contains formation and fabrication methods of wrinkled patterns and relevant mechanisms, as well as the induced mechanical, electrical, thermal and optical properties. Furthermore, these properties are modifiable by controlling the surface topography or even by dynamically stretching the 2D materials. Wrinkling offers a platform for 2D materials to be applied in some promising fields such as field emitters, energy containers and suppliers, field effect transistors, hydrophobic surfaces, sensors for flexible electronics and artificial intelligence. Finally, the opportunities and challenges of wrinkled 2D materials in the near future are discussed.
Collapse
Affiliation(s)
- Wenjun Chen
- State Key Laboratory of Optoelectronic Materials and Technologies, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou, 510275, P. R. China.
| | | | | | | | | |
Collapse
|
23
|
Pang J, Mendes RG, Bachmatiuk A, Zhao L, Ta HQ, Gemming T, Liu H, Liu Z, Rummeli MH. Applications of 2D MXenes in energy conversion and storage systems. Chem Soc Rev 2019; 48:72-133. [DOI: 10.1039/c8cs00324f] [Citation(s) in RCA: 978] [Impact Index Per Article: 195.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This article provides a comprehensive review of MXene materials and their energy-related applications.
Collapse
Affiliation(s)
- Jinbo Pang
- The Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden)
- Dresden
- Germany
- Institute for Advanced Interdisciplinary Research (iAIR)
- University of Jinan
| | - Rafael G. Mendes
- The Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden)
- Dresden
- Germany
- Soochow Institute for Energy and Materials InnovationS (SIEMIS)
- Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province
| | - Alicja Bachmatiuk
- The Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden)
- Dresden
- Germany
- Soochow Institute for Energy and Materials InnovationS (SIEMIS)
- Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province
| | - Liang Zhao
- Soochow Institute for Energy and Materials InnovationS (SIEMIS)
- Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province
- School of Energy
- Soochow University
- Suzhou
| | - Huy Q. Ta
- Soochow Institute for Energy and Materials InnovationS (SIEMIS)
- Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province
- School of Energy
- Soochow University
- Suzhou
| | - Thomas Gemming
- The Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden)
- Dresden
- Germany
| | - Hong Liu
- Institute for Advanced Interdisciplinary Research (iAIR)
- University of Jinan
- Jinan 250022
- China
- State Key Laboratory of Crystal Materials
| | - Zhongfan Liu
- Soochow Institute for Energy and Materials InnovationS (SIEMIS)
- Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province
- School of Energy
- Soochow University
- Suzhou
| | - Mark H. Rummeli
- The Leibniz Institute for Solid State and Materials Research Dresden (IFW Dresden)
- Dresden
- Germany
- Soochow Institute for Energy and Materials InnovationS (SIEMIS)
- Optoelectronics and Energy & Collaborative Innovation Center of Suzhou Nano Science and Technology, and Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province
| |
Collapse
|
24
|
Geng D, Yang HY. Recent Advances in Growth of Novel 2D Materials: Beyond Graphene and Transition Metal Dichalcogenides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1800865. [PMID: 30063268 DOI: 10.1002/adma.201800865] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/22/2018] [Indexed: 05/23/2023]
Abstract
Since the discovery of graphene just over a decade ago, 2D materials have been a central focus of materials research and engineering because of their unique properties and potential of revealing intriguing new phenomena. In the past few years, transition metal dichalcogenides (TMDs) have also attracted considerable attention because of the intrinsically opened bandgap. The exceptional properties and potential applications of graphene and TMDs have inspired explosive efforts to discover novel 2D materials. Here, emerging novel 2D materials are summarized and recent progress in the preparation, characterization, and application of 2D materials is highlighted. The experimental realization methods for these materials are emphasized, while the large-area growth and controlled patterning for industrial productions are discussed. Finally, the remaining challenges and potential applications of 2D materials are outlined.
Collapse
Affiliation(s)
- Dechao Geng
- Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| | - Hui Ying Yang
- Pillar of Engineering Product Development, Singapore University of Technology and Design, 8 Somapah Road, Singapore, 487372, Singapore
| |
Collapse
|
25
|
Preliminary study of the surface reactivity of 2D α-Mo 2
C crystallites. CAN J CHEM ENG 2018. [DOI: 10.1002/cjce.23286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
26
|
Jalil A, Sun Z, Wang D, Wu X. Magnetic and electronic properties of single-walled Mo 2C nanotube: a first-principles study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:155305. [PMID: 29498354 DOI: 10.1088/1361-648x/aab397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The structural, electronic, and magnetic properties of single-walled Mo2C nanotubes are investigated by using first-principles calculations. We establish that single-walled Mo2C nanotubes can be rolled up from a graphene-like Mo2C monolayer with H- or T-type phase, i.e. H-Mo2C and T-Mo2C nanotubes. The armchair-type T-Mo2C nanotubes are more energetically stable than H-Mo2C nanotubes with the same diameter, while zigzag-type H-Mo2C nanotubes are more energetically stable than T-Mo2C nanotubes. In particular, (8, 0) H-Mo2C nanotube are more stable than Mo2C monolayer due to structural deformation. All Mo2C nanotubes are magnetic metals, independent of their chirality, and the magnetic moments of Mo atoms in the outer layer are larger than the inner. The ionic and metallic bonds in Mo2C nanotubes and delocalized electrons around Mo atoms lead to the versatile electronic and magnetic properties in them, endowing them potential applications in catalysts and electronics.
Collapse
Affiliation(s)
- Abdul Jalil
- CAS Key Laboratory of Materials for Energy Conversion, School of Chemistry and Materials Sciences, and Hefei National Laboratory of Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China
| | | | | | | |
Collapse
|
27
|
Oh SM, Patil SB, Jin X, Hwang SJ. Recent Applications of 2D Inorganic Nanosheets for Emerging Energy Storage System. Chemistry 2018; 24:4757-4773. [DOI: 10.1002/chem.201704284] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Indexed: 01/14/2023]
Affiliation(s)
- Seung Mi Oh
- Center for Hybrid Interfacial Chemical Structure; Department of Chemistry and Nanoscience; College of Natural Sciences; Ewha Womans University; Seoul 03760 Korea
| | - Sharad B. Patil
- Center for Hybrid Interfacial Chemical Structure; Department of Chemistry and Nanoscience; College of Natural Sciences; Ewha Womans University; Seoul 03760 Korea
| | - Xiaoyan Jin
- Center for Hybrid Interfacial Chemical Structure; Department of Chemistry and Nanoscience; College of Natural Sciences; Ewha Womans University; Seoul 03760 Korea
| | - Seong-Ju Hwang
- Center for Hybrid Interfacial Chemical Structure; Department of Chemistry and Nanoscience; College of Natural Sciences; Ewha Womans University; Seoul 03760 Korea
| |
Collapse
|
28
|
Zhu Z, Zhan L, Wan W, Zhao Z, Shih TM, Cai W. Capabilities of transition metals in retarding the bonding of carbon atoms to minimize dendritic graphene. NANOSCALE 2017; 9:14804-14808. [PMID: 28956047 DOI: 10.1039/c7nr05253g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The avoidance of growing dendritic graphene on the copper substrate during the chemical vapor deposition process is greatly desired. Here we have identified a mechanism, in which (1) transition metal plates placed inside the copper pockets reduce the majority of active carbon atoms to eventually suppress the graphene growth rate, and (2) transition metals etch graphene C-C bonds along defective edges to grow into zigzag-edge ending domains with higher priorities. Via isotopic labeling of the methane method, we have observed bright-dark-alternating hexagonal-shaped rings, which are shown in Raman mapping images. Under a hydrogen atmosphere, we are capable of acquiring hexagonal openings within graphene domains by means of transition-metal-driven catalytic etching. This methodology may work as a simple and convenient way to determine graphene size and crystal orientation, and may enable the etching of graphene into smooth and ordered zigzag edge nanoribbons without compromising the quality of graphene.
Collapse
Affiliation(s)
- Zhenwei Zhu
- Department of Physics, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, 361005, China.
| | | | | | | | | | | |
Collapse
|
29
|
Lin Z, Cai L, Lu W, Chai Y. Phase and Facet Control of Molybdenum Carbide Nanosheet Observed by In Situ TEM. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:1700051. [PMID: 28481475 DOI: 10.1002/smll.201700051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 03/21/2017] [Indexed: 06/07/2023]
Abstract
Transition metal carbides are of great potential for electrochemical applications. The phase and facet of molybdenum carbides greatly affect the electrochemical performance. Carburization of MoO3 inside a transmission electron microscope to monitor the growth process of molybdenum carbides is performed. Carbon sources with different activities are used and the controllable growth of molybdenum carbides is investigated. The results show that the relatively inert amorphous carbon film produces Mo2 C, where the interstitial sites formed by hexagonal closed packing molybdenum atoms are partially occupied by carbon atoms. In contrast, the carbon decomposed from the sucrose has a high portion of sp3 hybridized and crosslinked carbon atoms with high reactivity, leading to the formation of MoC with full occupation of interstitial sites by carbon atoms. In addition, the MoC growth experiences a (111) to (100) facets change with the increase of temperature. The (111) facet formed at low temperature has Mo-terminated or C-terminated surface with higher surface energy and higher reactivity, while the (100) facet with 1:1 C/Mo ratio on the surface exhibits enhanced stability. The phase and facet control by carbon source and temperature allow us to tune the crystal structures and surface atoms as well as their electrochemical properties.
Collapse
Affiliation(s)
- Ziyuan Lin
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, P. R. China
| | - Lejuan Cai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, P. R. China
| | - Wei Lu
- University Research Facility in Materials Characterization and Device Fabrication, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, P. R. China
| | - Yang Chai
- Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, 999077, P. R. China
| |
Collapse
|
30
|
Geng D, Zhao X, Chen Z, Sun W, Fu W, Chen J, Liu W, Zhou W, Loh KP. Direct Synthesis of Large-Area 2D Mo 2 C on In Situ Grown Graphene. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29. [PMID: 28722179 DOI: 10.1002/adma.201700072] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/10/2017] [Indexed: 05/17/2023]
Abstract
As a new member of the MXene group, 2D Mo2 C has attracted considerable interest due to its potential application as electrodes for energy storage and catalysis. The large-area synthesis of Mo2 C film is needed for such applications. Here, the one-step direct synthesis of 2D Mo2 C-on-graphene film by molten copper-catalyzed chemical vapor deposition (CVD) is reported. High-quality and uniform Mo2 C film in the centimeter range can be grown on graphene using a Mo-Cu alloy catalyst. Within the vertical heterostructure, graphene acts as a diffusion barrier to the phase-segregated Mo and allows nanometer-thin Mo2 C to be grown. Graphene-templated growth of Mo2 C produces well-faceted, large-sized single crystals with low defect density, as confirmed by scanning transmission electron microscopy (STEM) measurements. Due to its more efficient graphene-mediated charge-transfer kinetics, the as-grown Mo2 C-on-graphene heterostructure shows a much lower onset voltage for hydrogen evolution reactions as compared to Mo2 C-only electrodes.
Collapse
Affiliation(s)
- Dechao Geng
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| | - Xiaoxu Zhao
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| | - Zhongxin Chen
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| | - Weiwei Sun
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN, 37235, USA
- Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
| | - Wei Fu
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| | - Jianyi Chen
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| | - Wei Liu
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| | - Wu Zhou
- Materials Science and Technology Division, Oak Ridge National Lab, Oak Ridge, TN, 37831, USA
- School of Physical Sciences, CAS Key Laboratory of Vacuum Physics, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kian Ping Loh
- Department of Chemistry and Centre for Advanced 2D Materials, National University of Singapore, 3 Science Drive 3, 17543, Singapore
| |
Collapse
|
31
|
Liu Z, Fei Z, Xu C, Jiang Y, Ma XL, Cheng HM, Ren W. Phase transition and in situ construction of lateral heterostructure of 2D superconducting α/β Mo 2C with sharp interface by electron beam irradiation. NANOSCALE 2017; 9:7501-7507. [PMID: 28530724 DOI: 10.1039/c7nr01609c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Lateral heterostructures of 2D materials have several interesting properties and potential applications, and they are usually fabricated by chemical vapor deposition. However, it still remains a great challenge to fabricate 2D lateral heterostructures with well-controlled patterns and sharp interfaces. Herein, we found that the 2D α-Mo2C crystal, a recently emerging 2D superconductor, experiences a phase transition from the α phase to β phase on electron beam irradiation in a transmission electron microscope because of the migration of carbon atoms among the molybdenum octahedrons. Combined with first-principles calculations, the carbon atom migration paths and the corresponding energy barriers were discussed. Utilizing this unique phase transition property of 2D α-Mo2C crystal, we demonstrated the precise in situ construction of the lateral heterostructure of 2D superconducting α/β Mo2C with a well-controlled pattern and sharp interface using advanced aberration-corrected scanning transmission electron microscopy.
Collapse
Affiliation(s)
- Zhibo Liu
- Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, P. R. China.
| | | | | | | | | | | | | |
Collapse
|