Nnepitaxial graphene on ruthenium pdf

Interfacial reactivity of ruthenium nanoparticles protected by ferrocenecarboxylates limei chen,a yang song, apeiguang hu, christopher p. Nitrogendoped graphene is an efficient catalyst for fuel. Introduction the unique properties of graphene have triggered numerous fundamental and technological studies. Study of graphene oxide structural features for catalytic. Jul 14, 20 the epitaxial growth of largearea singledomain graphene on hexagonal boron nitride by plasmaassisted deposition is now reported. Electronic properties of boron and nitrogendoped graphene. Epitaxial graphene is a graphene film that is directly grown on various crystalline surfaces. Electronic structure of epitaxial graphene layers on sic.

Synthesis of largearea, fewlayer graphene on iron foil. While as to bilayer and triple layer steps, graphene grains would nucleate at the edges, and given enough growth time graphene film at up step would connect together with that at down step. Nanocrystalline cubic ruthenium carbide formation in the. Ajayan b,e a department of materials science, lanzhou university, lanzhou 730000, pr china b department. Epitaxial graphene on silicon carbide has played a pivotal role in this development.

Catalysts that drive the oxygen reduction reaction that lets fuel cells turn chemical energy into electricity are. It can be wrapped up into 0d buckyballs, rolled into 1d nanotubes or stacked into 3d graphite. Nitrogendoped graphene is an efficient catalyst for fuel cells. The second uhv system is dedicated to graphene production, containing a graphite strip heater and pumped by a 150 ls turbomolecular pump and a hydrogengetter pump. In graphene field effect transistors gfet, graphene provides the active layer. However, the description graphene is not only used for single layers, but also for bilayer and few. Factors influencing graphene growth on metal surfaces arxiv. Epitaxial growth of ruthenium dioxides on ru0001 surface. The carbon atoms in a graphene layer are sp2hybridized.

Epitaxial graphene on ruthenium brookhaven national laboratory. To illustrate the activation of graphene via substrate engineering, zhang and coworkers turned to graphene on ru 0001 as the study system 11, as ru is one of the best substrates for graphene. F of a cluster of n atoms or molecules referred to generically as monomers calculated with respect to that of a single monomer, and specific to the prevailing conditions of temperature and monomer chemical potential in the environment. The emitting layer was composed of an organic metal complex of tris2, 2.

Supplementary information for epitaxial growth of singledomain graphene on hexagonal boron nitride wei yang1, guorui chen2, zhiwen shi1, chengcheng liu1,3, lianchang zhang1,4, guibai xie1, meng cheng1, duoming wang1, rong yang1, dongxia shi1, kenji watanabe5, takashi taniguchi 5, yugui yao 3, yuanbo zhang 2, and guangyu zhang1 1 beijing national laboratory. Scanning tunneling microscopy on epitaxial bilayer graphene on ruthenium 0001 article pdf available in applied physics letters 94. Ruthenium trisbipyridine functionalized gold nanoparticles 48 2. It is well known that graphene is a semimetal where the charge carriers behave as dirac fermions zero effective mass,1 which gives rise to. Stable ruthenium nanoparticles were synthesized in a biphasic system with a protecting monolayer of dithiocarbamate derivatives. However, the description graphene is not only used for single layers, but also for bilayer and fewlayer graphene up to about ten layers which all can be viewed as di. Herein, we report a facile, low cost, and environmentally friendly approach to prepare reduced graphene oxideruthenium oxide hybrid rgoruo2 materials. Deming, nan wang, jia en lu, and shaowei chen, department of chemistry and biochemistry, university of california, santa cruz, 1156 high street, santa cruz, california. Epitaxial rowth of ruthenium dioxides on ru0001 surface nien and zei.

Electronic transport properties of ruthenium and ruthenium. Thickness monitoring of graphene on sic using lowenergy. In this work, ruthenium oxide modified borondoped hierarchically porous reduced graphene aerogels ruo2bhrg are prepared by a solgel and. Epitaxial growth of singledomain graphene on hexagonal. Graphene, one of the allotropic forms of elemental carbon, is a planar monolayer of carbon atoms arranged on twodimensional hexagonal lattice with a carboncarbon bond length of 0. Deming,a yan guoab and shaowei chena stable ruthenium nanoparticles protected by ferrocenecarboxylates rufca were synthesized by thermolytic reduction of rucl 3 in 1,2propanediol. Introduction to structured graphene ming ruan1, yike hu1, zelei guo1, rui dong1, james palmer1, john hankinson1, claire berger1, 2, walt a. A layer of ruthenium just a few atoms thick can be used to finetune the sensitivity and enhance the reliability of magnetic sensors, tests at the national institute of standards and technology show. Simple lightemitting electrochemical cell using reduced graphene. Here, a graphene hybrid photodetector functionalized with a photoactive ruthenium complex that shows an ultrahigh responsivity of. Interfacial reactivity of ruthenium nanoparticles protected.

The carbon atoms of the graphene layer are orientationally registered and nearly commensurate with the atomic lattice of the substrate surface. Formation of hexagonal boron nitride on graphenecovered copper surfaces devashish p. Here, we report a simple and scalable way of preparing a threedimensional 3d sub5 nm hydrous ruthenium oxide ruo 2 anchored graphene and cnt hybrid foam rgm architecture for high. Liangbing gan, hongjun gao, and li gao, department of physics and astronomy, california state university, northridge, california 930, united states institute of physics, chinese academy of sciences, beijing. Although atomic force microscopy afm measurement is the most direct way to identify the number of layers of. Graphene grown on ruthenium doesnt typically yield a sample. Synthesis and characterization synthesis of ruthenium thiols, ruc3sh and rucrsh, were carried out as per scheme 2. Kaloni abstract effect of doping of graphene either by boron b, nitrogen n, or codoped by b and n is studied by density functional theory. The core size of the resulting ru particles was found to vary with the initial ligandmetal feed ratio. The formation of monolayer graphene was shown by raman spectroscopy, optical transmission, grazing incidence xray diffraction.

Subsequently, the epitaxy method was also used to produce graphene on ruthenium 42 thereupon, shortly followed by the cvd method of gaseous hydrocarbons to produce graphene 43,44. Aug 03, 2007 a layer of ruthenium just a few atoms thick can be used to finetune the sensitivity and enhance the reliability of magnetic sensors, tests at the national institute of standards and technology show. Ruthenium nitrosyl complexes with sulfur dominated coordination spheres. While at 910 c multilayer graphitic films are obtained, single layer defective graphene is formed at c. Controlled synthesis of nitrogendoped graphene on ruthenium from azafullerene xiangmin fei, joshua neilson, yanbang li, vanessa lopez, simon j. The synthesis process and doping properties have been investigated on the atomic scale by combining scanning tunneling microscopy and xray photoelectron spectroscopy measurements. Interaction, growth, and ordering of epitaxial graphene on sic0001 surfaces.

Controlled synthesis of nitrogendoped graphene on ruthenium. Our extensive band structure and density of states calculations. Graphene, a single sheet of sp2 bonded carbon atoms possessing unique and unusual electrical, mechanical, physical, and chemical properties, has the scientific community searching for samples viable in new technological applications, such as postcmos digital electronics and high frequency 100 ghz analog electronics. Epitaxial graphene on ru 0001 graphene ru 0001 is grown by catalytic decomposition of ethylene in uhv conditions. Facile synthesis of ultrasmall ruthenium oxide nanoparticles. For all the considered growth temperatures, few layers of graphene flg conformally covering the 100 to 200nm. Articles 12 s 30 s 60 s 90 s g ru 10 m a b figure 2 in situ microscopy of graphene epitaxy on ru 0001. Intervalence charge transfer of ruthenium nitrogen. Graphene on ni is considered to be one of the strong binding systems, like grapheneru0001, while graphenept111 is a weakly binding system in which the graphene binding is about the same as it is for pure graphite. Graphene is also the conceptual building block for some of these allotropes, including graphite, which is layered graphene, as well as nanotubes, which are graphene sheets that are.

Uvvis spectroscopic measurements showed a mie scattering pro. Lad an abstract of the thesis presented in partial fulfillment of the requirements for the degree of doctor of philosophy in physics may 2011 resistivities. An appropriate temperature and cooling process were. New sets of dirac points are produced as a result of a trigonal. These first two upper layers are considered monolayer, fig. Epitaxial graphene on cu111 nano letters acs publications. The monobromoalkyl bipyridine derivatives 2a and 2b were prepared through a nucleophilic reaction of 4,4dimethyl. Interaction, growth, and ordering of epitaxial graphene on. Feenstra1,a 1department of physics, carnegie mellon university. A simple method to synthesize continuous large area nitrogen. Epitaxial graphene growth on sic wafers semilab lei. Nanoscale structural characterization of epitaxial.

Graphene grown on ruthenium doesnt typically yield a. Sep 01, 2014 the maximum responsivity of a pure monolayer graphene. Direct observation of electron confinement in epitaxial. Raman spectroscopy and imaging of graphene and layer thickness determination a quick and precise method for determining the number of layers of graphene sheets is essential for speeding up the research and exploration of graphene.

This represents a difference in thermodynamic potential. Synthesis and photophysical properties of ruthenium. Ruthenium oxide modified hierarchically porous borondoped. Graphene is a 2d building material for carbon materials of all other dimensionalities. Despite these advantages, the performance of fuel cells depends largely on the oxygen reduction reaction orr the. Graphene ru 0001 shows a strong interaction between graphene and its substrate that results in a topographic and electronic modulation emerging as a moire pattern due to the lattice mismatch between both materials. Sutter center for functional nanomaterials, brookhaven. Structural and electronic properties of epitaxial graphene on. Epitaxial graphene films examined were formed on the siface of semiinsulating 4hsic substrates by a high temperature sublimation process. A simple method to synthesize continuous large area. Epitaxial growth of singledomain graphene on hexagonal boron. Compared with flat printed graphene, a substantial enhancement in the electrochemical performance was clearly observed for the case of 3d printed graphene pyramids with 5.

Ley lehrstuhl fur technische physik, universitat erlangennurnberg, erwinrommelstrasse 1, 91058 erlangen, germany. Epitaxial graphene on silicon carbide, on the other hand, is considered to be an ideal material for highend electronics that might be able to surpass silicon in terms of key parameters such as speed, feature size, and power consumption. Pdf scanning tunneling microscopy on epitaxial bilayer. Hydrous ruthenium oxide nanoparticles anchored to graphene. Substrate steps, visible as faint dark lines, are aligned from lower. Sep 15, 2011 we demonstrate a simple and controllable way to synthesize largearea, fewlayer graphene on iron substrates by an optimized chemical vapor deposition cvd method using a mixture of methane and hydrogen. Ruthenium atoms on graphene to match platinum standard for fuel cells nanowerk news rice university scientists have fabricated a durable catalyst for highperformance fuel cells by attaching single ruthenium atoms to graphene. Substrate steps, visible as faint dark lines, are aligned from.

The classic diagram of nucleation theory is the socalled free energy barrier sketched in fig. Nitrogen moieties embedded within nitrogendoped graphene quantum dots limei chen, peiguang hu, christopher p. A highk gate stack on the epitaxial graphene was realized by inserting a fully oxidized nanometer thin aluminum film as a seeding layer, followed by an atomiclayer deposition process. A simple method to synthesize continuous large area nitrogendoped graphene hui gao a,b, li song c,f, wenhua guo d, liang huang a, dezheng yang a, fangcong wang a, yalu zuo a, xiaolong fan a, zheng liu b, wei gao e, robert vajtai b, ken hackenberg b, pulickel m. Graphene grown on ruthenium doesnt typically yield a sample with a uniform from electronic 001 at international electronics and technical institute inc. The approximate electronic structure of a carbon nanotube with radius r is understood starting from the graphene dispersion relation, i.

Graphene is grown by chemical vapour deposition on ruthenium ultrathin films down to a nominal thickness of 5 nm. First principles study of the grapheneru0001 interface deen jiang1, maohua du2, and sheng dai 1 1chemical sciences division and 2materials science and technology division, oak ridge national laboratory, oak ridge, tennessee 37831 annealing the ru metal that typically contains residual carbon impurities offers a facile way to. Dec 12, 2012 nitrogendoped graphene is an efficient catalyst for fuel cells nanowerk spotlight fuel cells are able to convert chemical energy to electrical energy with little pollutant emission and high energy conversion efficiency. The supporting information is available free of charge on the acs publications website at doi.

Mar 25, 2014 here, we report a simple and scalable way of preparing a threedimensional 3d sub5 nm hydrous ruthenium oxide ruo 2 anchored graphene and cnt hybrid foam rgm architecture for high. The interfacial structure of epitaxial graphene on siface sic0001 has been controversial since its first observation in the 1970s. Grapheneruthenium complex hybrid photodetectors with. Scanning tunneling spectroscopy was used to measure differential conductance didv patterns of nanometersize. Strictly, the notion graphene represents a single layer of graphite. Electroresponsive supramolecular graphene oxide hydrogels for. In this work, we show that this interface is a warped graphene layer with periodic inclusions of pentagonhexagonheptagon h 5,6,7 topological defects within the honeycomb lattice. Based on an analysis of the fec phase diagram, a suitable procedure for the successful synthesis of graphene on fe surfaces was designed. Ruthenium atoms on graphene to match platinum standard for. The growth of graphene on single crystal cu111 has been achieved by thermal decomposition of ethylene in an ultrahigh vacuum chamber for the first time. Graphene materials and their use in dyesensitized solar cells joseph d. Carbon nanotubes are prototypical of quasi1d graphene nanostructures. For many applications, dielectrics layers such as sio 2 play a crucial role in device operation. Synthesis of largearea, fewlayer graphene on iron foil by.

Numbers indicate elapsed time in seconds after the nucleation of the graphene island. The controlled synthesis of highquality nitrogen n doped single layer graphene on the ru0001 surface has been achieved using the ncontaining sole precursor azafullerence c59nh. Atomistic description of oxide formation on metal surfaces. First principles study of the grapheneru0001 interface. The maximum responsivity of a pure monolayer graphene. Formation of hexagonal boron nitride on graphenecovered. The subsequent layers above layer 0 constitute the electrically active graphene, and give rise to its unique properties. The ability to nucleate and grow further graphene layers in a controlled way enables determination.

The extremely thin ru films allow the formation of a novel nanocrystalline rutheniu. The degree of chemical bonding of the graphene to the substrate varies from extremely weak to relatively. Atomistic simulation study of brittle failure in nanocrystalline graphene under uniaxial tension ajing cao1,a and jianmin qu1,2,b 1department of civil and environmental engineering, northwestern university, evanston, illinois 60208, usa 2department of mechanical engineering, northwestern university, evanston, illinois 60208, usa received 30 october 2012. A simple method to synthesize continuous large area nitrogendoped graphene hui gao a,b, li song c,f, wenhua guo d, liang huang a, dezheng yang a, fangcong wang a, yalu zuo a, xiaolong fan a, zheng liu b, wei gao e.

We demonstrate a simple and controllable way to synthesize largearea, fewlayer graphene on iron substrates by an optimized chemical vapor deposition cvd method using a mixture of methane and hydrogen. In contrast, here we find graphene grows both up and down the ir staircase, consistent. These h 5,6,7 regions deviate locally from the honeycomb lattice of. Graphene grows almost exclusively down the staircase of ru steps 26. Scanning tunneling microscopy images of monolayer graphene on the surfaces of 4hand 6hsic0001 siface show large flat regions with a characteristic hexagonal corrugation of. Synthesis and reactivity of ruthenium complexes with. The synthesis process and doping properties have been investigated on the atomic scale by combining scanning tunneling microscopy stm and xray photoelectron spectroscopy xps. The nucleation of monolayer islands and two predominant domain orientations. The structural and electronic properties of graphene on cu111 have been investigated by scanning tunneling microscopy and spectroscopy. Project disperses single atoms on graphene to match platinum standard.

Structural and electronic properties of epitaxial graphene. The epitaxial growth of largearea singledomain graphene on hexagonal boron nitride by plasmaassisted deposition is now reported. The synthesis process and doping properties have been investigated on the atomic scale by combining scanning tunneling microscopy stm and xray photoelectron. Intervalence charge transfer of ruthenium nitrogen moieties. The effects of ch4 partial pressure, growth temperature, and h2ch4 ratio were investigated and growth conditions optimized. Approach to multifunctional device platform with epitaxial. Graphene gr is a very attractive material for diverse optoelectronic and electronic device applications due to its extraordinary transport properties, broad spectralbandwidth, and fast response time 1,2,3,4. Electronic transport properties of ruthenium and ruthenium dioxide thin films by michael m.