201
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Jing Y, Zhou Z. Computational Insights into Oxygen Reduction Reaction and Initial Li2O2 Nucleation on Pristine and N-Doped Graphene in Li–O2 Batteries. ACS Catal 2015. [DOI: 10.1021/acscatal.5b00332] [Citation(s) in RCA: 147] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yu Jing
- Tianjin
Key Laboratory of Metal and Molecule Based Material Chemistry, Key
Laboratory of Advanced Energy Materials Chemistry (Ministry of Education),
Computational Centre for Molecular Science, Institute of New Energy
Material Chemistry, School of Materials Science and Engineering, Collaborative Innovation Center of Chemical Science
and Engineering (Tianjin), Nankai University, Tianjin 300071, People’s Republic of China
| | - Zhen Zhou
- Tianjin
Key Laboratory of Metal and Molecule Based Material Chemistry, Key
Laboratory of Advanced Energy Materials Chemistry (Ministry of Education),
Computational Centre for Molecular Science, Institute of New Energy
Material Chemistry, School of Materials Science and Engineering, Collaborative Innovation Center of Chemical Science
and Engineering (Tianjin), Nankai University, Tianjin 300071, People’s Republic of China
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202
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Xiang Z, Wang D, Xue Y, Dai L, Chen JF, Cao D. PAF-derived nitrogen-doped 3D Carbon Materials for Efficient Energy Conversion and Storage. Sci Rep 2015; 5:8307. [PMID: 26045229 PMCID: PMC4456730 DOI: 10.1038/srep08307] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 12/22/2014] [Indexed: 11/25/2022] Open
Abstract
Owing to the shortage of the traditional fossil fuels caused by fast consumption, it is an urgent task to develop the renewable and clean energy sources. Thus, advanced technologies for both energy conversion (e.g., solar cells and fuel cells) and storage (e.g., supercapacitors and batteries) are being studied extensively. In this work, we use porous aromatic framework (PAF) as precursor to produce nitrogen-doped 3D carbon materials, i.e., N-PAF-Carbon, by exposing NH3 media. The “graphitic” and “pyridinic” N species, large surface area, and similar pore size as electrolyte ions endow the nitrogen-doped PAF-Carbon with outstanding electronic performance. Our results suggest the N-doping enhance not only the ORR electronic catalysis but also the supercapacitive performance. Actually, the N-PAF-Carbon obtains ~70 mV half-wave potential enhancement and 80% increase as to the limiting current after N doping. Moreover, the N-PAF-Carbon displays free from the CO and methanol crossover effect and better long-term durability compared with the commercial Pt/C benchmark. Moreover, N-PAF-Carbon also possesses large capacitance (385 F g−1) and excellent performance stability without any loss in capacitance after 9000 charge–discharge cycles. These results clearly suggest that PAF-derived N-doped carbon material is promising metal-free ORR catalyst for fuel cells and capacitor electrode materials.
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Affiliation(s)
- Zhonghua Xiang
- Centre of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (USA)
| | - Dan Wang
- 1] Centre of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (USA) [2] State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (P.R. China)
| | - Yuhua Xue
- Centre of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (USA)
| | - Liming Dai
- Centre of Advanced Science and Engineering for Carbon (Case4Carbon), Department of Macromolecular Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106 (USA)
| | - Jian-Feng Chen
- State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (P.R. China)
| | - Dapeng Cao
- State Key Lab of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (P.R. China)
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203
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Bhattacharjee J. Activation of Graphenic Carbon Due to Substitutional Doping by Nitrogen: Mechanistic Understanding from First Principles. J Phys Chem Lett 2015; 6:1653-1660. [PMID: 26263329 DOI: 10.1021/acs.jpclett.5b00304] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nitrogen-doped graphene and carbon nanotubes are popularly in focus as metal-free electrocatalysts for oxygen reduction reactions (ORR) central to fuel cells. N-doped CNTs have been also reported to chemisorb mutually, promising a route to their robust predetermined assembly into devices and mechanical reinforcements. We propose from first principles a common mechanistic understanding of these two aspects pointing further to a generic chemical activation of carbon atoms due to substitution by nitrogen in experimentally observed configurations. Wannier-function based orbital resolved study of mechanisms suggests increase in C-N bond-orders in attempt to retain π-conjugation among carbon atoms, causing mechanical stress and loss of charge neutrality of nitrogen and carbon atoms, which remedially facilitate chemical activation of N-coordinated C atoms, enhancing sharply with increasing coordination to N and proximity to zigzag edges. Activated C atoms facilitate covalent adsorption of radicals in general, diradicals like O2 relevant to ORR, and also other similarly activated C atoms, leading to self-assembly of graphenic nanostructures while remaining inert to ordinary graphenic C atoms.
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Affiliation(s)
- Joydeep Bhattacharjee
- School of Physical Sciences, National Institute of Science Education and Research, IOP campus, Sachivalay Marg, Bhubaneswar 751005, India
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204
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Dai L, Xue Y, Qu L, Choi HJ, Baek JB. Metal-Free Catalysts for Oxygen Reduction Reaction. Chem Rev 2015; 115:4823-92. [DOI: 10.1021/cr5003563] [Citation(s) in RCA: 1830] [Impact Index Per Article: 203.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Liming Dai
- Center
of Advanced Science and Engineering for Carbon (Case4Carbon), Department
of Macromolecular Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Yuhua Xue
- Center
of Advanced Science and Engineering for Carbon (Case4Carbon), Department
of Macromolecular Science and Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Liangti Qu
- Key
Laboratory of Cluster Science, Ministry of Education of China, Beijing
Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials,
Department of Chemistry, School of Science, Beijing Institute of Technology, Beijing 100081, People’s Republic of China
| | - Hyun-Jung Choi
- School
of Energy and Chemical Engineering/Center for Dimension-Controllable
Covalent Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon, Ulsan, 689-798, South Korea
| | - Jong-Beom Baek
- School
of Energy and Chemical Engineering/Center for Dimension-Controllable
Covalent Organic Frameworks, Ulsan National Institute of Science and Technology (UNIST), 100 Banyeon, Ulsan, 689-798, South Korea
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205
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Hughes ZE, Walsh TR. Computational chemistry for graphene-based energy applications: progress and challenges. NANOSCALE 2015; 7:6883-6908. [PMID: 25833794 DOI: 10.1039/c5nr00690b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Research in graphene-based energy materials is a rapidly growing area. Many graphene-based energy applications involve interfacial processes. To enable advances in the design of these energy materials, such that their operation, economy, efficiency and durability is at least comparable with fossil-fuel based alternatives, connections between the molecular-scale structure and function of these interfaces are needed. While it is experimentally challenging to resolve this interfacial structure, molecular simulation and computational chemistry can help bridge these gaps. In this Review, we summarise recent progress in the application of computational chemistry to graphene-based materials for fuel cells, batteries, photovoltaics and supercapacitors. We also outline both the bright prospects and emerging challenges these techniques face for application to graphene-based energy materials in future.
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Affiliation(s)
- Zak E Hughes
- Institute for Frontier Materials, Deakin University, Geelong, VIC 3216, Australia.
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206
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Vicarelli L, Heerema SJ, Dekker C, Zandbergen HW. Controlling defects in graphene for optimizing the electrical properties of graphene nanodevices. ACS NANO 2015; 9:3428-35. [PMID: 25864552 PMCID: PMC4415450 DOI: 10.1021/acsnano.5b01762] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Structural defects strongly impact the electrical transport properties of graphene nanostructures. In this Perspective, we give a brief overview of different types of defects in graphene and their effect on transport properties. We discuss recent experimental progress on graphene self-repair of defects, with a focus on in situ transmission electron microscopy studies. Finally, we present the outlook for graphene self-repair and in situ experiments.
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207
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Zhang J, Zhang M, Lin L, Wang X. Sol Processing of Conjugated Carbon Nitride Powders for Thin-Film Fabrication. Angew Chem Int Ed Engl 2015; 54:6297-301. [DOI: 10.1002/anie.201501001] [Citation(s) in RCA: 325] [Impact Index Per Article: 36.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/10/2015] [Indexed: 11/09/2022]
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208
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Zhang J, Zhang M, Lin L, Wang X. Sol Processing of Conjugated Carbon Nitride Powders for Thin-Film Fabrication. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501001] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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209
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210
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Li XF, Lian KY, Qiu Q, Luo Y. Half-filled energy bands induced negative differential resistance in nitrogen-doped graphene. NANOSCALE 2015; 7:4156-4162. [PMID: 25665635 DOI: 10.1039/c4nr07472f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nitrogen-doping brings novel properties and promising applications into graphene, but the underlying mechanism is still in debate. To determine the key factor in motivating the negative differential resistance (NDR) behaviour of nitrogen-doped graphene, the electronic structure and transport properties of an 11-dimer wide nitrogen-doped armchair graphene nanoribbon (N-AGNR) were systematically studied by first principles calculations. Both the effect of interaction between N-dopants and the effect of doping-sublattice on the NDR were examined for the first time. Taking into account the two effects, N-AGNR becomes metallic or semiconducting depending on the doping configuration, and its Fermi level varies in a large range. NDR was firmly verified not to be intrinsic for N-AGNRs. However, it is totally determined by whether nitrogen-doping induces half-filled energy bands (HFEBs) because it is HFEBs that cross the Fermi level and determine the transport properties of N-AGNR under low biases. With the bias increasing, the transmission spectrum near the Fermi level showed a flag shape, and therefore, the corresponding transport channel is totally suppressed at a certain bias, resulting in the NDR behaviour with a configuration-dependent peak-to-valley current ratio (PVCR) up to 10(4). Our findings give new insights into the microscopic mechanism of chemical doping induced NDR behaviour and will be useful in building NDR-based nanodevices in the future.
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Affiliation(s)
- Xiao-Fei Li
- School of Optoelectronic Information, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054, P. R. China.
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211
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Rein M, Richter N, Parvez K, Feng X, Sachdev H, Kläui M, Müllen K. Magnetoresistance and charge transport in graphene governed by nitrogen dopants. ACS NANO 2015; 9:1360-1366. [PMID: 25548883 DOI: 10.1021/nn5057063] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We identify the influence of nitrogen-doping on charge- and magnetotransport of single layer graphene by comparing doped and undoped samples. Both sample types are grown by chemical vapor deposition (CVD) and transferred in an identical process onto Si/SiO2 wafers. We characterize the samples by Raman spectroscopy as well as by variable temperature magnetotransport measurements. Over the entire temperature range, the charge transport properties of all undoped samples are in line with literature values. The nitrogen doping instead leads to a 6-fold increase in the charge carrier concentration up to 4 × 10(13) cm(-2) at room temperature, indicating highly effective doping. Additionally it results in the opening of a charge transport gap as revealed by the temperature dependence of the resistance. The magnetotransport exhibits a conspicuous sign change from positive Lorentz magnetoresistance (MR) in undoped to large negative MR that we can attribute to the doping induced disorder. At low magnetic fields, we use quantum transport signals to quantify the transport properties. Analyses based on weak localization models allow us to determine an orders of magnitude decrease in the phase coherence and scattering times for doped samples, since the dopants act as effective scattering centers.
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Affiliation(s)
- Markus Rein
- Institut für Physik, Johannes Gutenberg-Univsersity , 55128 Mainz, Germany
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212
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Iyer GRS, Wang J, Wells G, Bradley MP, Borondics F. Nanoscale imaging of freestanding nitrogen doped single layer graphene. NANOSCALE 2015; 7:2289-2294. [PMID: 25584935 DOI: 10.1039/c4nr05385k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Graphene can be p-type or n-type doped by introduction of specific species. Doping can modulate the electronic properties of graphene, but opening a sizable-well-tuned bandgap is essential for graphene-based tunable electronic devices. N-doped graphene is widely used for device applications and is mostly achieved by introducing ammonia into the synthesis gas during the chemical vapor deposition (CVD) process. Post synthesis treatment studies to fine-tune the electron hole doping in graphene are limited. In this work realization of N-doping in large area freestanding single layer graphene (LFG) is achieved by post treatment in nitrogen plasma. The changes in the chemical and electronic properties of graphene are followed with Raman microscopy and mapped via synchrotron based scanning transmission X-ray microscopy (STXM) at the nanoscale.
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Affiliation(s)
- Ganjigunte R S Iyer
- Canadian Light Source, 44 Innovation Boulevard, Saskatoon, SK S7N 2V3, Canada.
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213
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Rozada R, Paredes JI, López MJ, Villar-Rodil S, Cabria I, Alonso JA, Martínez-Alonso A, Tascón JMD. From graphene oxide to pristine graphene: revealing the inner workings of the full structural restoration. NANOSCALE 2015; 7:2374-90. [PMID: 25563664 DOI: 10.1039/c4nr05816j] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
High temperature annealing is the only method known to date that allows the complete repair of a defective lattice of graphenes derived from graphite oxide, but most of the relevant aspects of such restoration processes are poorly understood. Here, we investigate both experimentally (scanning probe microscopy) and theoretically (molecular dynamics simulations) the thermal evolution of individual graphene oxide sheets, which is rationalized on the basis of the generation and the dynamics of atomic vacancies in the carbon lattice. For unreduced and mildly reduced graphene oxide sheets, the amount of generated vacancies was so large that they disintegrated at 1773-2073 K. By contrast, highly reduced sheets survived annealing and their structure could be completely restored at 2073 K. For the latter, a minor atomic-sized defect with six-fold symmetry was observed and ascribed to a stable cluster of nitrogen dopants. The thermal behavior of the sheets was significantly altered when they were supported on a vacancy-decorated graphite substrate, as well as for the overlapped/stacked sheets. In these cases, a net transfer of carbon atoms between neighboring sheets via atomic vacancies takes place, affording an additional healing process. Direct evidence of sheet coalescence with the step edge of the graphite substrate was also gathered from experiments and theory.
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Affiliation(s)
- Rubén Rozada
- Instituto Nacional del Carbón, INCAR-CSIC, Apartado 73, 33080 Oviedo, Spain.
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214
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Zhao L, He R, Zabet-Khosousi A, Kim KS, Schiros T, Roth M, Kim P, Flynn GW, Pinczuk A, Pasupathy AN. Dopant segregation in polycrystalline monolayer graphene. NANO LETTERS 2015; 15:1428-1436. [PMID: 25625227 DOI: 10.1021/nl504875x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Heterogeneity in dopant concentration has long been important to the electronic properties in chemically doped materials. In this work, we experimentally demonstrate that during the chemical vapor deposition process, in contrast to three-dimensional polycrystals, the substitutional nitrogen atoms avoid crystal grain boundaries and edges over micron length scales while distributing uniformly in the interior of each grain. This phenomenon is universally observed independent of the details of the growth procedure such as temperature, pressure, substrate, and growth precursor.
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Affiliation(s)
- Liuyan Zhao
- Department of Physics, Columbia University , New York, New York 10027, United States
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215
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Wei D, Peng L, Li M, Mao H, Niu T, Han C, Chen W, Wee ATS. Low temperature critical growth of high quality nitrogen doped graphene on dielectrics by plasma-enhanced chemical vapor deposition. ACS NANO 2015; 9:164-171. [PMID: 25581685 DOI: 10.1021/nn505214f] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Nitrogen doping is one of the most promising routes to modulate the electronic characteristic of graphene. Plasma-enhanced chemical vapor deposition (PECVD) enables low-temperature graphene growth. However, PECVD growth of nitrogen doped graphene (NG) usually requires metal-catalysts, and to the best of our knowledge, only amorphous carbon-nitrogen films have been produced on dielectric surfaces by metal-free PECVD. Here, a critical factor for metal-free PECVD growth of NG is reported, which allows high quality NG crystals to be grown directly on dielectrics like SiO2/Si, Al2O3, h-BN, mica at 435 °C without a catalyst. Thus, the processes needed for loading the samples on dielectrics and n-type doping are realized in a simple PECVD, which would be of significance for future graphene electronics due to its compatibility with the current microelectronic processes.
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Affiliation(s)
- Dacheng Wei
- Department of Macromolecular Science, Fudan University , Shanghai 200433, China
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216
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Tison Y, Lagoute J, Repain V, Chacon C, Girard Y, Rousset S, Joucken F, Sharma D, Henrard L, Amara H, Ghedjatti A, Ducastelle F. Electronic interaction between nitrogen atoms in doped graphene. ACS NANO 2015; 9:670-678. [PMID: 25558891 DOI: 10.1021/nn506074u] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Many potential applications of graphene require either the possibility of tuning its electronic structure or the addition of reactive sites on its chemically inert basal plane. Among the various strategies proposed to reach these objectives, nitrogen doping, i.e., the incorporation of nitrogen atoms in the carbon lattice, leads in most cases to a globally n-doped material and to the presence of various types of point defects. In this context, the interactions between chemical dopants in graphene have important consequences on the electronic properties of the systems and cannot be neglected when interpreting spectroscopic data or setting up devices. In this report, the structural and electronic properties of complex doping sites in nitrogen-doped graphene have been investigated by means of scanning tunneling microscopy and spectroscopy, supported by density functional theory and tight-binding calculations. In particular, based on combined experimental and simulation works, we have systematically studied the electronic fingerprints of complex doping configurations made of pairs of substitutional nitrogen atoms. Localized bonding states are observed between the Dirac point and the Fermi level in contrast with the unoccupied state associated with single substitutional N atoms. For pyridinic nitrogen sites (i.e., the combination of N atoms with vacancies), a resonant state is observed close to the Dirac energy. This insight into the modifications of electronic structure induced by nitrogen doping in graphene provides us with a fair understanding of complex doping configurations in graphene, as it appears in real samples.
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Affiliation(s)
- Yann Tison
- Laboratoire Matériaux et Phénoménes Quantiques, CNRS-Université Paris 7 , 10 Rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
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217
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Unni SM, Bhange SN, Illathvalappil R, Mutneja N, Patil KR, Kurungot S. Nitrogen-induced surface area and conductivity modulation of carbon nanohorn and its function as an efficient metal-free oxygen reduction electrocatalyst for anion-exchange membrane fuel cells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:352-360. [PMID: 25155361 DOI: 10.1002/smll.201303892] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Revised: 07/09/2014] [Indexed: 06/03/2023]
Abstract
Nitrogen-doped carbon morphologies have been proven to be better alternatives to Pt in polymer-electrolyte membrane (PEM) fuel cells. However, efficient modulation of the active sites by the simultaneous escalation of the porosity and nitrogen doping, without affecting the intrinsic electrical conductivity, still remains to be solved. Here, a simple strategy is reported to solve this issue by treating single-walled carbon nanohorn (SWCNH) with urea at 800 °C. The resulting nitrogen-doped carbon nanohorn shows a high surface area of 1836 m2 g(-1) along with an increased electron conductivity, which are the pre-requisites of an electrocatalyst. The nitrogen-doped nanohorn annealed at 800 °C (N-800) also shows a high oxygen reduction activity (ORR). Because of the high weight percentage of pyridinic nitrogen coordination in N-800, the present catalyst shows a clear 4-electron reduction pathway at only 50 mV overpotential and 16 mV negative shift in the half-wave potential for ORR compared to Pt/C along with a high fuel selectivity and electrochemical stability. More importantly, a membrane electrode assembly (MEA) based on N-800 provides a maximum power density of 30 mW cm(-2) under anion-exchange membrane fuel cell (AEMFC) testing conditions. Thus, with its remarkable set of physical and electrochemical properties, this material has the potential to perform as an efficient Pt-free electrode for AEMFCs.
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Affiliation(s)
- Sreekuttan M Unni
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune, Maharashtra, 411008, India; Academy of Scientific and Innovative Research (AcSIR), Anusandhan Bhawan, 2 Rafi Marg, New Delhi, 110001, India
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218
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Susi T, Pichler T, Ayala P. X-ray photoelectron spectroscopy of graphitic carbon nanomaterials doped with heteroatoms. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2015; 6:177-92. [PMID: 25671162 PMCID: PMC4311644 DOI: 10.3762/bjnano.6.17] [Citation(s) in RCA: 133] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/08/2014] [Indexed: 05/03/2023]
Abstract
X-ray photoelectron spectroscopy (XPS) is one of the best tools for studying the chemical modification of surfaces, and in particular the distribution and bonding of heteroatom dopants in carbon nanomaterials such as graphene and carbon nanotubes. Although these materials have superb intrinsic properties, these often need to be modified in a controlled way for specific applications. Towards this aim, the most studied dopants are neighbors to carbon in the periodic table, nitrogen and boron, with phosphorus starting to emerge as an interesting new alternative. Hundreds of studies have used XPS for analyzing the concentration and bonding of dopants in various materials. Although the majority of works has concentrated on nitrogen, important work is still ongoing to identify its precise atomic bonding configurations. In general, care should be taken in the preparation of a suitable sample, consideration of the intrinsic photoemission response of the material in question, and the appropriate spectral analysis. If this is not the case, incorrect conclusions can easily be drawn, especially in the assignment of measured binding energies into specific atomic configurations. Starting from the characteristics of pristine materials, this review provides a practical guide for interpreting X-ray photoelectron spectra of doped graphitic carbon nanomaterials, and a reference for their binding energies that are vital for compositional analysis via XPS.
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Affiliation(s)
- Toma Susi
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Thomas Pichler
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Vienna, Austria
| | - Paola Ayala
- University of Vienna, Faculty of Physics, Boltzmanngasse 5, A-1090 Vienna, Austria
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219
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Abstract
Doped, substituted, or alloyed graphene is an attractive candidate for use as a tunable element of future nanomechanical and optoelectronic devices. Here we use the density functional theory, density functional tight binding, cluster expansion, and molecular dynamics to investigate the thermal stability and electronic properties of a binary 2D alloy of graphitic carbon and nitrogen (C(1-x)N(x)). The stability range naturally begins from graphene and must end before x = 1, where pure nitrogen rather forms molecular gas. This poses a compelling question of what highest x < 1 still permits stable 2D hexagonal lattice. Such upper limit on the nitrogen concentration that is achievable in a stable alloy can be found based on the phonon and molecular dynamics calculations. The stability switchover is predicted to between x = 1/3 (33.3%) and x = 3/8 (37.5%), and no stable hexagonal lattice two-dimensional CN alloys can exist at the N concentration of x = 3/8 (37.5%) and higher.
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Affiliation(s)
- Zhiming Shi
- †The State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
- ‡Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States
| | - Alex Kutana
- ‡Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States
| | - Boris I Yakobson
- ‡Department of Materials Science and Nanoengineering, Rice University, Houston, Texas 77005, United States
- §Department of Chemistry, Rice University, Houston, Texas 77005, United States
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220
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Xiang Z, Cao D, Dai L. Well-defined two dimensional covalent organic polymers: rational design, controlled syntheses, and potential applications. Polym Chem 2015. [DOI: 10.1039/c4py01383b] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent developments in the design, synthesis and application of 2D covalent organic polymers are reviewed, along with some perspectives and challenges.
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Affiliation(s)
- Zhonghua Xiang
- Center of Advanced Science and Engineering for Carbon (Case4Carbon)
- Department of Macromolecular Science and Engineering
- Case Western Reserve University
- Cleveland
- USA
| | - Dapeng Cao
- State Key Lab of Organic–Inorganic Composites
- Beijing University of Chemical Technology
- Beijing 100029
- P.R. China
| | - Liming Dai
- Center of Advanced Science and Engineering for Carbon (Case4Carbon)
- Department of Macromolecular Science and Engineering
- Case Western Reserve University
- Cleveland
- USA
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221
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Colherinhas G, Fileti EE, Chaban VV. Can inorganic salts tune electronic properties of graphene quantum dots? Phys Chem Chem Phys 2015; 17:17413-20. [DOI: 10.1039/c5cp02083b] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this work, we apply density functional theory to study the effect of neutral ionic clusters adsorbed on the GQD surface. We conclude that both the HOMO and the LUMO of GQDs are very sensitive to the presence of ions and to their distance from the GQD surface. However, the alteration of the band gap itself is modest, as opposed to the case of free ions (recent reports). Our work fosters progress in modulating electronic properties of nanoscale carbonaceous materials.
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Affiliation(s)
| | - Eudes Eterno Fileti
- Instituto de Ciência e Tecnologia
- Universidade Federal de São Paulo
- São José dos Campos
- Brazil
| | - Vitaly V. Chaban
- Instituto de Ciência e Tecnologia
- Universidade Federal de São Paulo
- São José dos Campos
- Brazil
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222
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Du H, Wang Z, Chen Y, Liu Y, Liu Y, Li B, Wang X, Cao H. Anchoring superparamagnetic core–shells onto reduced graphene oxide: fabrication of Ni–carbon–rGO nanocomposite for effective adsorption and separation. RSC Adv 2015. [DOI: 10.1039/c4ra14651d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The magnetic Ni nanoparticles encapsulated in carbon shells were anchored on to reduced graphene oxide. The excellent removal ability of organic dyes and enhanced separation efficiency make NGC a useful candidate for waste water treatment.
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Affiliation(s)
- Hang Du
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Zhen Wang
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Yinghao Chen
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Yanyan Liu
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Yushan Liu
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Baojun Li
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
- Department of Chemistry
| | - Xiangyu Wang
- College of Chemistry and Molecular Engineering
- Zhengzhou University
- Zhengzhou 450001
- P. R. China
| | - Huaqiang Cao
- Department of Chemistry
- Tsinghua University
- Beijing 100084
- P. R. China
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223
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Ferre-Vilaplana A, Herrero E. Charge transfer, bonding conditioning and solvation effect in the activation of the oxygen reduction reaction on unclustered graphitic-nitrogen-doped graphene. Phys Chem Chem Phys 2015; 17:16238-42. [PMID: 26054255 DOI: 10.1039/c5cp00918a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Under certain conditions and on specific sites the monodentate associative chemisorption of molecular oxygen on graphitic-nitrogen-doped graphene would be favorable.
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Affiliation(s)
- Adolfo Ferre-Vilaplana
- Instituto Tecnológico de Informática
- Ciudad Politécnica de la Innovación
- E-46022 Valencia
- Spain
- Departamento de Sistemas Informáticos y Computación
| | - Enrique Herrero
- Instituto de Electroquímica
- Universidad de Alicante
- E-03080 Alicante
- Spain
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224
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Anand B, Karakaya M, Prakash G, Sankara Sai SS, Philip R, Ayala P, Srivastava A, Sood AK, Rao AM, Podila R. Dopant-configuration controlled carrier scattering in graphene. RSC Adv 2015. [DOI: 10.1039/c5ra05338b] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Our detailed Raman, non-linear optical, and photoemission spectroscopic studies evince that the N-dopant configuration in graphene (blue-pyridinic, orange-graphitic, and red-pyrrolic) can be effectively tuned to mitigate electron-defect scattering.
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Affiliation(s)
- Benoy Anand
- Department of Physics
- Sri Sathya Sai Institute of Higher Learning
- Puttaparthi
- India
| | - Mehmet Karakaya
- Department of Physics and Astronomy, and Clemson Nanomaterials Center
- Clemson University
- Clemson
- USA
| | - Gyan Prakash
- Department of Physics and Center for Ultrafast Laser Applications
- Indian Institute of Science
- Bangalore
- India
| | - S. Siva Sankara Sai
- Department of Physics
- Sri Sathya Sai Institute of Higher Learning
- Puttaparthi
- India
| | - Reji Philip
- Light and Matter Physics Group
- Raman Research Institute
- Bangalore
- India
| | - Paola Ayala
- Faculty of Physics
- University of Vienna
- A-1090 Vienna
- Austria
- School of Physical Sciences and Nanotechnology
| | - Anurag Srivastava
- Advanced Materials Research Group and Computational Nanoscience & Technology Lab
- ABV-Indian Institute of Information Technology
- Gwalior
- India
| | - Ajay K. Sood
- Department of Physics and Center for Ultrafast Laser Applications
- Indian Institute of Science
- Bangalore
- India
| | - Apparao M. Rao
- Department of Physics and Astronomy, and Clemson Nanomaterials Center
- Clemson University
- Clemson
- USA
| | - Ramakrishna Podila
- Department of Physics and Astronomy, and Clemson Nanomaterials Center
- Clemson University
- Clemson
- USA
- Laboratory of Nano-biophysics, and Center for Optical Materials Science and Engineering Technologies
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225
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Kim HS, Kim HS, Kim SS, Kim YH. Atomistic mechanisms of codoping-induced p- to n-type conversion in nitrogen-doped graphene. NANOSCALE 2014; 6:14911-8. [PMID: 25363732 DOI: 10.1039/c4nr05024j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
It was recently shown that nitrogen-doped graphene (NG) can exhibit both p- and n-type characters depending on the C-N bonding nature, which represents a significant bottleneck for the development of graphene-based electronics. Based on first-principles calculations, we herein scrutinize the correlations between the atomic and electronic structures of NG and particularly explore the feasibility of converting p-type NG with pyridinic, pyrrolic, and nitrilic N atoms into n- or bipolar type by introducing an additional dopant atom. Of the nine candidates B, C, O, F, Al, Si, P, S, and Cl, we find that B-, Al-, and P-codoping can anneal even relatively large vacancy defects in p-type NG. It will be also shown that, while the NG with pyridinic N can be converted into the n-type via codoping, only a bipolar type conversion can be achieved for the NG with nitrilic or pyrrolic N. The amount of work function reduction was up to 0.64 eV for the pyridinic N next to a monovacancy. The atomistic origin of such diverse type changes is analyzed based on Mulliken and crystal orbital Hamiltonian populations, which provide us with a framework to connect the local bonding chemistry with the macroscopic electronic structure in doped and/or defective graphene. Moreover, we demonstrate that the proposed codoping scheme can recover the excellent charge transport properties of pristine graphene. Both the electronic type conversion and conductance recovery in codoped NG should have significant implications for the electronic and energy device applications.
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Affiliation(s)
- Hyo Seok Kim
- Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Korea.
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226
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Tang Y, Wu D, Mai Y, Pan H, Cao J, Yang C, Zhang F, Feng X. A two-dimensional hybrid with molybdenum disulfide nanocrystals strongly coupled on nitrogen-enriched graphene via mild temperature pyrolysis for high performance lithium storage. NANOSCALE 2014; 6:14679-14685. [PMID: 25380029 DOI: 10.1039/c4nr05519e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A novel 2D hybrid with MoS(2) nanocrystals strongly coupled on nitrogen-enriched graphene (MoS(2)/NG(g-C(3)N(4))) is realized by mild temperature pyrolysis (550 °C) of a self-assembled precursor (MoS(3)/g-C(3)N(4)-H(+)/GO). With rich active sites, the boosted electronic conductivity and the coupled structure, MoS(2)/NG(g-C(3)N(4)) achieves superior lithium storage performance.
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Affiliation(s)
- Yanping Tang
- School of Chemistry and Chemical Engineering, Shanghai JiaoTong University, 200240, Shanghai, China.
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227
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Margapoti E, Strobel P, Asmar MM, Seifert M, Li J, Sachsenhauser M, Ceylan O, Palma CA, Barth JV, Garrido JA, Cattani-Scholz A, Ulloa SE, Finley JJ. Emergence of photoswitchable states in a graphene-azobenzene-Au platform. NANO LETTERS 2014; 14:6823-6827. [PMID: 25414977 DOI: 10.1021/nl503681z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The perfect transmission of charge carriers through potential barriers in graphene (Klein tunneling) is a direct consequence of the Dirac equation that governs the low-energy carrier dynamics. As a result, localized states do not exist in unpatterned graphene, but quasibound states can occur for potentials with closed integrable dynamics. Here, we report the observation of resonance states in photoswitchable self-assembled molecular(SAM)-graphene hybrid. Conductive AFM measurements performed at room temperature reveal strong current resonances, the strength of which can be reversibly gated on- and off- by optically switching the molecular conformation of the mSAM. Comparisons of the voltage separation between current resonances (∼ 70-120 mV) with solutions of the Dirac equation indicate that the radius of the gating potential is ∼ 7 ± 2 nm with a strength ≥ 0.5 eV. Our results and methods might provide a route toward optically programmable carrier dynamics and transport in graphene nanomaterials.
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Affiliation(s)
- Emanuela Margapoti
- Walter Schottky Institute - ZNN, Physik Department and NIM, Technische Universität München , Am Coulombwall 4, 80333 Garching, Germany
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228
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Lv R, dos Santos MC, Antonelli C, Feng S, Fujisawa K, Berkdemir A, Cruz-Silva R, Elías AL, Perea-Lopez N, López-Urías F, Terrones H, Terrones M. Large-area Si-doped graphene: controllable synthesis and enhanced molecular sensing. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:7593-7599. [PMID: 25355604 DOI: 10.1002/adma.201403537] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 09/22/2014] [Indexed: 06/04/2023]
Abstract
Large-area Si-doped graphene (SiG) is controllably synthesized for the first time. A much-enhanced molecular-sensing performance is achieved when SiG is used as a probing surface. This will open up opportunities for developing high-performance sensors that are able to detect trace amounts of organic and fluorescent molecules. Furthermore, many fascinating properties predicted by theoretical calculations can be tested based on the as-synthesized SiG.
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Affiliation(s)
- Ruitao Lv
- Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
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229
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Favaro M, Ferrighi L, Fazio G, Colazzo L, Di Valentin C, Durante C, Sedona F, Gennaro A, Agnoli S, Granozzi G. Single and Multiple Doping in Graphene Quantum Dots: Unraveling the Origin of Selectivity in the Oxygen Reduction Reaction. ACS Catal 2014. [DOI: 10.1021/cs501211h] [Citation(s) in RCA: 145] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Marco Favaro
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Lara Ferrighi
- Dipartimento
di Scienza dei Materiali, Università di Milano-Bicocca, Via
Cozzi 53, 20125 Milano, Italy
| | - Gianluca Fazio
- Dipartimento
di Scienza dei Materiali, Università di Milano-Bicocca, Via
Cozzi 53, 20125 Milano, Italy
| | - Luciano Colazzo
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Cristiana Di Valentin
- Dipartimento
di Scienza dei Materiali, Università di Milano-Bicocca, Via
Cozzi 53, 20125 Milano, Italy
| | - Christian Durante
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Francesco Sedona
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Armando Gennaro
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Stefano Agnoli
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Gaetano Granozzi
- Department
of Chemical Sciences, Università degli studi di Padova, Via Marzolo 1, 35131 Padova, Italy
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230
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Warner JH, Lin YC, He K, Koshino M, Suenaga K. Stability and spectroscopy of single nitrogen dopants in graphene at elevated temperatures. ACS NANO 2014; 8:11806-11815. [PMID: 25389658 DOI: 10.1021/nn5054798] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Single nitrogen (N) dopants in graphene are investigated using atomic-resolution scanning transmission electron microscopy (STEM) combined with electron energy loss spectroscopy (EELS). Using an in situ heating holder at 500 °C provided us with clean graphene surfaces, and we demonstrate that isolated N substitutional atoms remain localized and stable in the graphene lattice even during local sp(2) bond reconstruction. The high stability of isolated N dopants enabled us to acquire 2D EELS maps with simultaneous ADF-STEM images to map out the local bonding variations. We show that a substitutional N dopant causes changes in the EELS of the carbon (C) atoms it is directly bonded to. An upshift in the π* peak of the C K-edge EELS of ∼0.5 eV is resolved and supported by density functional theory simulations.
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Affiliation(s)
- Jamie H Warner
- Department of Materials, University of Oxford , Parks Road, Oxford, OX1 3PH, U.K
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231
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Botello-Méndez AR, Dubois SMM, Lherbier A, Charlier JC. Achievements of DFT for the investigation of graphene-related nanostructures. Acc Chem Res 2014; 47:3292-300. [PMID: 25350633 DOI: 10.1021/ar500281v] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
CONSPECTUS: Graphene-related nanostructures stand out as exceptional materials due to both their wide range of properties and their expanse of interest in both applied and fundamental research. They are good examples of nanoscale materials for which the properties do not necessarily replicate those of the bulk. For the description and the understanding of their properties, it is clear that a general quantum-mechanical approach is mandatory. The remarkable result of density functional theory (DFT) is that the quantum-mechanical description of materials at the ground state is made amenable to simulations at a relatively low computational cost. The knowledge of materials has undergone a revolution after the introduction of DFT as an unrivaled instrument for the investigation of materials properties through computer experiments. Their deeper understanding comes from a variety of tools developed from concepts intrinsically present in DFT, notably the total energy and the charge density. Such tools allow the prediction of a diverse set of physicochemical properties relevant for material scientists. This Account lays out an example-driven tour through the achievements of ground-state DFT applied to the description of graphene-related nanostructures and to the deep understanding of their outstanding properties. After a brief introduction to DFT, the survey starts with the determination of the most basic properties that can be obtained from DFT, that is, band structures, lattice parameters, and spin ground state. Next follows an exploration of how total energies of different systems can give information about relative stability, formation energies, and reaction paths. Exploiting the derivatives of the energy with respect to displacements leads the way toward the extraction of vibrational and mechanical properties. In addition, a close examination of the charge density gives information about charge transfer mechanisms, which can be linked to chemical reactivity. The ground state density and Hamiltonian finally connect to the concepts behind transport phenomena, which drive much of the application-oriented research on graphene and graphene-related nanostructures. In each section, a selection of cases that are of current importance are used to illustrate the use and relevance of DFT-based techniques. In summary, this Account presents an introductory landscape of the possibilities of ground-state DFT for the study of graphene-related nanostructures. The prospect is rich, and the use of DFT for the study of graphene-related nanostructures will continue to be fruitful for the advancement of these and other materials.
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Affiliation(s)
- Andrés R. Botello-Méndez
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
| | - Simon M.-M. Dubois
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
| | - Aurélien Lherbier
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
| | - Jean-Christophe Charlier
- Institute of Condensed
Matter
and Nanosciences, Université catholique de Louvain, Chemin des
étoiles 8, 1348 Louvain-la-neuve, Belgium
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232
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Ma D, Liu M, Gao T, Li C, Sun J, Nie Y, Ji Q, Zhang Y, Song X, Zhang Y, Liu Z. High-quality monolayer graphene synthesis on Pd foils via the suppression of multilayer growth at grain boundaries. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:4003-4011. [PMID: 24913919 DOI: 10.1002/smll.201400421] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/06/2014] [Indexed: 06/03/2023]
Abstract
The segregation of carbon from metals in which carbon is highly soluble, such as Ni (≈1.1 atom% at 1000 °C), is a typical method for graphene growth; this method differs from the surface-catalyzed growth of graphene that occurs on other metals such as Cu (<0.04 atom%). It has not been established whether strictly monolayer graphene could be synthesized through the traditional chemical vapor deposition route on metals where carbon is highly soluble, such as Pd (≈3.5 atom%). In this work, this issue is investigated by suppressing the grain boundary segregation using a pretreatment comprising the annealing of the Pd foils; this method was motivated by the fact that the typical thick growths at the grain boundaries revealed that the grain boundary functions as the main segregation channel in polycrystalline metals. To evaluate the high crystallinity of the as-grown graphene, detailed atomic-scale characterization with scanning tunneling microscopy is performed.
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Affiliation(s)
- Donglin Ma
- Center for Nanochemistry (CNC), Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, People's Republic of China
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233
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Arenal R, March K, Ewels CP, Rocquefelte X, Kociak M, Loiseau A, Stéphan O. Atomic configuration of nitrogen-doped single-walled carbon nanotubes. NANO LETTERS 2014; 14:5509-16. [PMID: 25157857 DOI: 10.1021/nl501645g] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Having access to the chemical environment at the atomic level of a dopant in a nanostructure is crucial for the understanding of its properties. We have performed atomically resolved electron energy-loss spectroscopy to detect individual nitrogen dopants in single-walled carbon nanotubes and compared with first-principles calculations. We demonstrate that nitrogen doping occurs as single atoms in different bonding configurations: graphitic-like and pyrrolic-like substitutional nitrogen neighboring local lattice distortion such as Stone-Thrower-Wales defects. We also show that the largest fraction of nitrogen amount is found in poly aromatic species that are adsorbed on the surface of the nanotube walls. The stability under the electron beam of these nanotubes has been studied in two different cases of nitrogen incorporation content and configuration. These findings provide key information for the applications of these nanostructures.
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Affiliation(s)
- Raul Arenal
- Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Universidad de Zaragoza , Calle Mariano Esquillor, 50018 Zaragoza, Spain
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234
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Pham VD, Lagoute J, Mouhoub O, Joucken F, Repain V, Chacon C, Bellec A, Girard Y, Rousset S. Electronic interaction between nitrogen-doped graphene and porphyrin molecules. ACS NANO 2014; 8:9403-9409. [PMID: 25187965 DOI: 10.1021/nn503753e] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The chemical doping of graphene is a promising route to improve the performances of graphene-based devices through enhanced chemical reactivity, catalytic activity, or transport characteristics. Understanding the interaction of molecules with doped graphene at the atomic scale is therefore a leading challenge to be overcome for the development of graphene-based electronics and sensors. Here, we use scanning tunneling microscopy and spectroscopy to study the electronic interaction of pristine and nitrogen-doped graphene with self-assembled tetraphenylporphyrin molecules. We provide an extensive measurement of the electronic structure of single porphyrins on Au(111), thus revealing an electronic decoupling effect of the porphyrins adsorbed on graphene. A tip-induced switching of the inner hydrogen atoms of porphyrins, first identified on Au(111), is observed on graphene, allowing the identification of the molecular conformation of porphyrins in the self-assembled molecular layer. On nitrogen-doped graphene, a local modification of the charge transfer around the nitrogen sites is evidenced via a downshift of the energies of the molecular elecronic states. These data show how the presence of nitrogen atoms in the graphene network modifies the electronic interaction of organic molecules with graphene. These results provide a basic understanding for the exploitation of doped graphene in molecular sensors or nanoelectronics.
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Affiliation(s)
- Van Dong Pham
- Laboratoire Matériaux et Phénomènes Quantiques, CNRS-Université Paris 7 , 10 Rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
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235
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Usachov D, Fedorov A, Vilkov O, Senkovskiy B, Adamchuk VK, Yashina LV, Volykhov AA, Farjam M, Verbitskiy NI, Grüneis A, Laubschat C, Vyalikh DV. The chemistry of imperfections in N-graphene. NANO LETTERS 2014; 14:4982-4988. [PMID: 25136909 DOI: 10.1021/nl501389h] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Many propositions have been already put forth for the practical use of N-graphene in various devices, such as batteries, sensors, ultracapacitors, and next generation electronics. However, the chemistry of nitrogen imperfections in this material still remains an enigma. Here we demonstrate a method to handle N-impurities in graphene, which allows efficient conversion of pyridinic N to graphitic N and therefore precise tuning of the charge carrier concentration. By applying photoemission spectroscopy and density functional calculations, we show that the electron doping effect of graphitic N is strongly suppressed by pyridinic N. As the latter is converted into the graphitic configuration, the efficiency of doping rises up to half of electron charge per N atom.
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Affiliation(s)
- Dmitry Usachov
- St. Petersburg State University , 198504 St. Petersburg, Russia
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236
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Choi I, Jeong HY, Jung DY, Byun M, Choi CG, Hong BH, Choi SY, Lee KJ. Laser-induced solid-phase doped graphene. ACS NANO 2014; 8:7671-7. [PMID: 25006987 DOI: 10.1021/nn5032214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
There have been numerous efforts to improve the performance of graphene-based electronic devices by chemical doping. Most studies have focused on gas-phase doping with chemical vapor deposition. However, that requires a complicated transfer process that causes undesired doping and defects by residual polymers. Here, we report a solid-phase synthesis of doped graphene by means of silicon carbide (SiC) substrate including a dopant source driven by pulsed laser irradiation. This method provides in situ direct growth of doped graphene on an insulating SiC substrate without a transfer step. A numerical simulation on the temperature history of the SiC surface during laser irradiation reveals that the surface temperature of SiC can be accurately controlled to grow nitrogen-doped graphene from the thermal decomposition of nitrogen-doped SiC. Laser-induced solid-phase doped graphene is highly promising for the realization of graphene-based nanoelectronics with desired functionalities.
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Affiliation(s)
- Insung Choi
- Department of Materials Science and Engineering and ‡Department of Electrical Engineering and Graphene Research Center, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 305-701, Republic of Korea
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237
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Bai KK, Zhou Y, Zheng H, Meng L, Peng H, Liu Z, Nie JC, He L. Creating one-dimensional nanoscale periodic ripples in a continuous mosaic graphene monolayer. PHYSICAL REVIEW LETTERS 2014; 113:086102. [PMID: 25192109 DOI: 10.1103/physrevlett.113.086102] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Indexed: 06/03/2023]
Abstract
In previous studies, it has proved difficult to realize periodic graphene ripples with wavelengths of a few nanometers. Here we show that one-dimensional (1D) periodic graphene ripples with wavelengths from 2 nm to tens of nanometers can be implemented in the intrinsic areas of a continuous mosaic (locally N-doped) graphene monolayer by simultaneously using both the thermal strain engineering and the anisotropic surface stress of the Cu substrate. Our result indicates that the constraint imposed at the boundaries between the intrinsic and the N-doped regions play a vital role in creating these 1D ripples. We also demonstrate that the observed rippling modes are beyond the descriptions of continuum mechanics due to the decoupling of graphene's bending and tensional deformations. Scanning tunneling spectroscopy measurements indicate that the nanorippling generates a periodic electronic superlattice and opens a zero-energy gap of about 130 meV in graphene. This result may pave a facile way for tailoring the structures and electronic properties of graphene.
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Affiliation(s)
- Ke-Ke Bai
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Yu Zhou
- Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Hong Zheng
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Lan Meng
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Hailin Peng
- Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Zhongfan Liu
- Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China
| | - Jia-Cai Nie
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Lin He
- Department of Physics, Beijing Normal University, Beijing 100875, People's Republic of China
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238
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Xue Y, Wu B, Bao Q, Liu Y. Controllable synthesis of doped graphene and its applications. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:2975-2991. [PMID: 24715648 DOI: 10.1002/smll.201400706] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Indexed: 06/03/2023]
Abstract
Graphene is a wonder material with the ultimate smallest thickness that is readily accessible to various approaches for engineering its excellent properties. Graphene doping is an efficient way to tailor its electric properties and expand its applications. This topic covers wide research fields and has been developing rapidly. This article presents a broad and comprehensive overview of the developments in the preparation and applications of doped graphene including doping methods, doping levels, doping effect and types of heteroatoms. Very recent advances are also presented. In addition, existing problems in terms of achieving greater control over and further developments of doped graphene are also discussed.
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Affiliation(s)
- Yunzhou Xue
- Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China; Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
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239
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Sutter P, Huang Y, Sutter E. Nanoscale integration of two-dimensional materials by lateral heteroepitaxy. NANO LETTERS 2014; 14:4846-4851. [PMID: 25054434 DOI: 10.1021/nl502110q] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Materials integration in heterostructures with novel properties different from those of the constituents has become one of the most powerful concepts of modern materials science. Two-dimensional (2D) crystals represent a new class of materials from which such engineered structures can be envisioned. Calculations have predicted emergent properties in 2D heterostructures with nanoscale feature sizes, but methods for their controlled fabrication have been lacking. Here, we use sequential graphene and boron nitride growth on Ru(0001) to show that lateral heteroepitaxy, the joining of 2D materials by preferential incorporation of different atomic species into exposed 1D edges during chemical vapor deposition on a metal substrate, can be used for the bottom-up synthesis of 2D heterostructures with characteristic dimensions on the nanoscale. Our results suggest that on a proper substrate, this method lends itself to building nanoheterostructures from a wide range of 2D materials.
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Affiliation(s)
- Peter Sutter
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States
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240
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Single adatom dynamics at monatomic steps of free-standing few-layer reduced graphene. Sci Rep 2014; 4:6037. [PMID: 25113125 PMCID: PMC4129415 DOI: 10.1038/srep06037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 07/25/2014] [Indexed: 11/09/2022] Open
Abstract
Steps and their associated adatoms extensively exist and play prominent roles in affecting surface properties of materials. Such impacts should be especially pronounced in two-dimensional, atomically-thin membranes like graphene. However, how single adatom behaves at monatomic steps of few-layer graphene is still illusive. Here, we report dynamics of individual adatom at monatomic steps of free-standing few-layer reduced graphene under the electron beam radiations, and demonstrate the prevalent existence of monatomic steps even down to unexpectedly ultrasmall lateral size of a circular diameter of ~5 Å. Single adatom prefers to stay at the edges of the atomic steps of few-layer reduced graphene and evolve with the steps. Moreover, we also find that how the single adatom behaves at atomic step edges can be remarkably influenced by the type of adatoms and step edges. Such single adatoms at monatomic steps and ultrasmall atomic steps open up a new window for surface physics and chemistry for graphene-based as well as other two-dimensional materials.
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241
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Kwak D, Khetan A, Noh S, Pitsch H, Han B. First Principles Study of Morphology, Doping Level, and Water Solvation Effects on the Catalytic Mechanism of Nitrogen-Doped Graphene in the Oxygen Reduction Reaction. ChemCatChem 2014. [DOI: 10.1002/cctc.201402248] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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242
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Bong JH, Sul O, Yoon A, Choi SY, Cho BJ. Facile graphene n-doping by wet chemical treatment for electronic applications. NANOSCALE 2014; 6:8503-8508. [PMID: 24946832 DOI: 10.1039/c4nr01160k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We report a post-synthetic n-doping method for chemical-vapor-deposition (CVD) grown graphene using wet chemical processing. An ammonium fluoride solution was found effective in converting pristine hole doping into electron doping in addition to the mobility improvement of charge carriers. We verified the doping by electrical measurements, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) analyses and suggest that the mechanism of n-doping is electrostatic doping by ionic physisorption of ammonium ions on the graphene surface. This simple chemical doping method provides a facile and robust route to n-doping of large area graphene for the realization of high performance graphene-based electronic devices.
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Affiliation(s)
- Jae Hoon Bong
- Department of Electrical Engineering, KAIST, Daejeon 305-701, Republic of Korea.
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243
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Lawlor JA, Ferreira MS. Sublattice asymmetry of impurity doping in graphene: A review. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2014; 5:1210-7. [PMID: 25161855 PMCID: PMC4142872 DOI: 10.3762/bjnano.5.133] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 07/08/2014] [Indexed: 05/28/2023]
Abstract
In this review we highlight recent theoretical and experimental work on sublattice asymmetric doping of impurities in graphene, with a focus on substitutional nitrogen dopants. It is well known that one current limitation of graphene in regards to its use in electronics is that in its ordinary state it exhibits no band gap. By doping one of its two sublattices preferentially it is possible to not only open such a gap, which can furthermore be tuned through control of the dopant concentration, but in theory produce quasi-ballistic transport of electrons in the undoped sublattice, both important qualities for any graphene device to be used competetively in future technology. We outline current experimental techniques for synthesis of such graphene monolayers and detail theoretical efforts to explain the mechanisms responsible for the effect, before suggesting future research directions in this nascent field.
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Affiliation(s)
- James A Lawlor
- School of Physics, Trinity College Dublin, Dublin 2, Ireland
| | - Mauro S Ferreira
- School of Physics, Trinity College Dublin, Dublin 2, Ireland
- CRANN, Trinity College Dublin, Dublin 2, Ireland
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244
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Goran JM, Favela CA, Stevenson KJ. Investigating the Electrocatalytic Oxidation of Dihydronicotinamide Adenine Dinucleotide at Nitrogen-Doped Carbon Nanotube Electrodes: Implications to Electrochemically Measuring Dehydrogenase Enzyme Kinetics. ACS Catal 2014. [DOI: 10.1021/cs5006794] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Jacob M. Goran
- Department of Chemistry,
Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
| | - Carlos A. Favela
- Department of Chemistry,
Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
| | - Keith J. Stevenson
- Department of Chemistry,
Center for Nano- and Molecular Science and Technology, The University of Texas at Austin, 105 East 24th Street, Stop A5300, Austin, Texas 78712-1224, United States
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245
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Koós AA, Murdock AT, Nemes-Incze P, Nicholls RJ, Pollard AJ, Spencer SJ, Shard AG, Roy D, Biró LP, Grobert N. Effects of temperature and ammonia flow rate on the chemical vapour deposition growth of nitrogen-doped graphene. Phys Chem Chem Phys 2014; 16:19446-52. [DOI: 10.1039/c4cp02132k] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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246
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Telychko M, Mutombo P, Ondráček M, Hapala P, Bocquet FC, Kolorenč J, Vondráček M, Jelínek P, Švec M. Achieving high-quality single-atom nitrogen doping of graphene/SiC(0001) by ion implantation and subsequent thermal stabilization. ACS NANO 2014; 8:7318-24. [PMID: 24884035 DOI: 10.1021/nn502438k] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
We report a straightforward method to produce high-quality nitrogen-doped graphene on SiC(0001) using direct nitrogen ion implantation and subsequent stabilization at temperatures above 1300 K. We demonstrate that double defects, which comprise two nitrogen defects in a second-nearest-neighbor (meta) configuration, can be formed in a controlled way by adjusting the duration of bombardment. Two types of atomic contrast of single N defects are identified in scanning tunneling microscopy. We attribute the origin of these two contrasts to different tip structures by means of STM simulations. The characteristic dip observed over N defects is explained in terms of the destructive quantum interference.
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247
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Liu YL, Yu CC, Lin KT, Wang EY, Yang TC, Chen HL, Chen CW, Chang CK, Chen LC, Chen KH. Nondestructive Characterization of the Structural Quality and Thickness of Large-Area Graphene on Various Substrates. Anal Chem 2014; 86:7192-9. [DOI: 10.1021/ac501557c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yu-Lun Liu
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Chen-Chieh Yu
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Keng-Te Lin
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - En-Yun Wang
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Tai-Chi Yang
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Hsuen-Li Chen
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Chun-Wei Chen
- Department
of Materials Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Cheng-Kai Chang
- Institute
of Polymer Science and Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Li-Chyong Chen
- Center
for Condensed Matter Science, National Taiwan University, Taipei, 10617, Taiwan
| | - Kuei-Hsien Chen
- Center
for Condensed Matter Science, National Taiwan University, Taipei, 10617, Taiwan
- Institute
of Atomic and Molecular Sciences, Academia Sinica, Taipei, 10617, Taiwan
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248
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Prezzi D, Eom D, Rim KT, Zhou H, Xiao S, Nuckolls C, Heinz TF, Flynn GW, Hybertsen MS. Edge structures for nanoscale graphene islands on Co(0001) surfaces. ACS NANO 2014; 8:5765-5773. [PMID: 24830340 DOI: 10.1021/nn500583a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Low-temperature scanning tunneling microscopy measurements and first-principles calculations are employed to characterize edge structures observed for graphene nanoislands grown on the Co(0001) surface. Images of these nanostructures reveal straight well-ordered edges with zigzag orientation, which are characterized by a distinct peak at low bias in tunneling spectra. Density functional theory based calculations are used to discriminate between candidate edge structures. Several zigzag-oriented edge structures have lower formation energy than armchair-oriented edges. Of these, the lowest formation energy configurations are a zigzag and a Klein edge structure, each with the final carbon atom over the hollow site in the Co(0001) surface. In the absence of hydrogen, the interaction with the Co(0001) substrate plays a key role in stabilizing these edge structures and determines their local conformation and electronic properties. The calculated electronic properties for the low-energy edge structures are consistent with the measured scanning tunneling images.
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Affiliation(s)
- Deborah Prezzi
- Nanoscience Institute, CNR , S3 Center, I-41125 Modena, Italy
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249
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Brito WH, Chacham H, Kagimura R, Miwa RH. Electronic confinement in graphene ruled by N doped extended defects. NANOTECHNOLOGY 2014; 25:245706. [PMID: 24870126 DOI: 10.1088/0957-4484/25/24/245706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We investigate by means of ab-initio simulations the formation energy and the electronic properties of substitutional N doping in graphene with distinct grain boundary defects as a function of the N concentration. Our results show that the presence of substitutional N atoms along the defective regions is quite likely for several N concentrations. Also, we find either semiconducting or metallic structures, depending on the N concentration. Confinement effects were also investigated for the semiconducting structures. We find that the distance between the defect lines can modulate the band structure of those semiconducting N doped lines. This opens an interesting possibility to produce two-dimensional heterojunctions composed by N doped grain boundaries with different distances between the defect lines.
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Affiliation(s)
- W H Brito
- Departamento de Física, Universidade Federal de Minas Gerais, CP 702, 31270-901, Belo Horizonte, MG, Brazil
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250
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Huang Y, Wu D, Wang J, Han S, Lv L, Zhang F, Feng X. Amphiphilic polymer promoted assembly of macroporous graphene/SnO2 frameworks with tunable porosity for high-performance lithium storage. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:2226-2232. [PMID: 24515284 DOI: 10.1002/smll.201303423] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 12/26/2013] [Indexed: 06/03/2023]
Abstract
3D macroporous graphene/SnO2 frameworks (MGTFs) are fabricated by amphiphilic polymer-promoted assembly method, which exhibit controllable macroporous structure and outstanding lithium storage performance.
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Affiliation(s)
- Yanshan Huang
- School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, 200240, P. R. China
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