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Pillared Graphites – A New 3D Network Nanostructure for enhanced Hydrogen Storage Dimitrakakis K. Georgios 1 , Tylianakis Emmanuel 2 and Froudakis George E. 1* 1 Department of Chemistry, University of Crete, P.O. Box 2208, Heraklion, Crete, 71003, Greece 2 Materials Science and Technology Department, University of Crete, P.O. Box 2208, Heraklion, Crete, 71003, Greece * frudakis@chemistry.uoc.gr Hydrogen is considered to be one of the most promising energy fuels. It can be stored in fuel cells in order to make easier and safer its transportation and usage in mobile applications. After the synthesis of Carbon Nanotubes (CNTs) [1] the scientific research has been focused on them, as they are believed to be a good candidate material for reversible hydrogen storage [2-4]. So far, the results have shown [5-7] that in ambient conditions, the hydrogen storage capacity of pristine CNTs is far below the gravimetric and volumetric targets that have been set by the U.S. Department of Energy (D.O.E.) [8]. Doping CNTs with alkali metals like Lithium has as a result higher storage capacity [9-13] but even that remains far away from the D.O.E. targets. All these have lead to the proposal of new candidate structures based on carbon [14-16]. In the present work a novel three dimensional (3D) carbon based architecture is proposed as a new enhanced hydrogen storage material. The proposed structure consists of parallel graphite sheets build in such a way that they use CNTs as pillars for the connection. The resulted 3D networked nanostructure can be seen in Figure 1. Ab-initio calculations were performed to show the possibility of forming such a structure. They were done using the Density Functional Theory (DFT) level and the PBE functional. Our calculations showed that something like this is theoretically feasible and thus we continued to see how such a structure interacts with hydrogen atoms. In addition, more calculations were carried out when this structure was doped with a lithium atom. Furthermore, Monte – Carlo calculations were conducted to measure the ability of this structure to adsorb hydrogen. The uptake depends on both intertube and intersheet distance and also on the tube’s curvature. The results were encouraging compared with previous studies. A 50% enhancement is observed related to graphene sheets and nanotubes. Finally, when this novel material is doped with Li ions the volumetric uptake reaches 49 gr H 2 /Lit, fulfilling the DOE’s target i.e. 45 gr H 2 /Lit [8]. Figure 1 191
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XXIII ΠΑΝΕΛΛΗΝΙΟ ΣΥΝΕ
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Κοιτώντας τα πρακτ
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ΕΠΙΤΡΟΠΕΣ Οργανωτι
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ΠΡΟΓΡΑΜΜΑ ΣΥΝΕΔΡΙΟ
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21. Οργανικά τρανζίσ
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15:30 15:45 16:00 16:15 16:30 16:45
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41. Modeling and quantitative phase
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Ανοιχτή Συνεδρία «
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«NανοΥλικά και Νανο
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New materials and MOS device concep
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Reliability Characteristics of Rare
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Ο λόγος των ταχυτήτ
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Thus the mean R In-In is expected t
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FIG 1. Schematic representation of
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με 0.80 eV στη διεπιφά
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Εντοπισµός Φορέων
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Παρασκευή και Xαρακ
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Electrical Spin Injection from Fe i
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Electrical Spin Injection of Spin-P
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References [1] CH Lee, J. Meteer, V
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Σχήμα 1: Φωτογραφία
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SEM Image Layout Simulation Εικ
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Μελέτη Ατελειών Σε
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Facet-Stress-Driven Ordering in SiG
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νανοκρυσταλλίτης (a
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Σχήµα 1. Εικόνες περ
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Σχήµα 1. Εικόνες περ
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Οι δομές που αναπτύ
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Raman Intensity (10 -50 cm 3 ) 1,2
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Μελέτη της Επίδρασ
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Annealing Induced Dissociation of N
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`Εναπόθεση με Παλμι
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Μελέτη της Χημείας
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Ανάπτυξη Νέων Μεσο
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Application of Thermal Quadrupoles
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Στοχαστική προσομο
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Νανοτραχύτητα κατά
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Ευαισθησία και Δια
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Optical Properties of CuIn 1-x Ga x
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ανοπτημένο με λέιζ
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Στο σχήμα 3 φαίνοντ
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Id (mA) -0,3 -0,2 -0,1 Vg=0 Vg=-1 V
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Strained-Si Si 1-x Ge x graded Si 1
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Fig. 1. Laser mask movement during
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forwarded to the back interface dur
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Σχήμα 2: Εκθετική εξ
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V th (V) G m,max /G m,max0 (%) I d
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C/ C ox 1,0 0,8 0,6 0,4 0,2 0,0 -4
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και Ta 2 O 5 , των οποίω
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κατασκευή της. Η πα
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ΔP (mW) 12 10 8 6 4 2 0 0 500 1000
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υπολογίσουμε θεωρη
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Σχήμα 2 Σύστημα ηλε
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Μελέτη των Μηχανισ
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Ανάπτυξη και Μελέτ
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Structure and Magnetic Properties o
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Δομή και Μαγνητικέ
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Μετρήσεις Ειδικής
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Further, almost all of the observed
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g-factor 2.019 2.016 2.013 2.010 2.
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ρυθμό 4 C.min -1 , έπειτ
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ΜΕΛΕΤΗ ΤΟΥ ΦΑΙΝΟΜΕ
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Νέοι Εξαφερίτες Ba µ
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Crystal Structure of a new Supramol
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Magnetic Phase Transition in Synthe
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Συσχέτιση πλαστική
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Μετασχηματισμοί φά
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Μελέτη της Επίδρασ
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Resonant Spin Transfer Torque in Do
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3 η Προφορική Συνεδ
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technology, and e-beam lithography.
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ecause it reduces the calculation o
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Υπολογισμός Υψηλής
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The thermodynamic average is obtain
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ΑΠΟΤΕΛΕΣΜΑΤΑ Στην
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προερχόµενη είτε α
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Combining Magnetism and Ferroelectr
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υµένια LCMO/STO (100) πολ
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Our scheme is illustrated in Fig. 1
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[6] . Η μελέτη του υλι
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τα πειραµατικά µας
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Page 169 and 170: Αυτο-οργάνωση και Μ
Page 171 and 172: Viscoelastic Response of Micelles w
Page 173 and 174: Διηλεκτρική απόκρι
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Page 187 and 188: ∆οµή και ∆υναµική
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Page 191 and 192: (α) (β) Σχήμα 2: (α) Απε
Page 193 and 194: Figure 3. Generation 4 PAMAM-H 2 O
Page 195 and 196: Από όλα τα παραπάνω
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Page 209 and 210: Σύνθεση και Χαρακτ
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Page 217 and 218: Figure 3: GCMC calculations for und
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Page 227 and 228: Συναπόθεση Cr - Ni σε
Page 229 and 230: Investigation of the Structural, Mo
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Page 233 and 234: Templated Sol-Gel Synthesis Of TiO
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Page 237 and 238: Preparation of YSZ Solid Electrolyt
Page 239 and 240: Σύνθεση, Ανισοτροπ
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Page 243 and 244: Local Coordination of Zn and Fe in
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Page 249 and 250: Μηχανικές Iδιότητε
Page 251 and 252: The Influence of Thermal Aging on t
Page 253 and 254: Modeling and quantitative phase ana
Page 255 and 256: Συμβολή στη Συντήρ
Page 257 and 258: Κρυσταλλική Συµπερ
Page 259 and 260: Σύνθεση Στερεών ∆ι
Page 261 and 262: Fabrication and Characterization of
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Συγκριτική αξιολόγ
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6 η Προφορική Συνεδ
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Ηλεκτρομαγνητική Α
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Φασματοσκοπική Μελ
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Thermal and Electrical Properties o
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Structure, Mechanical, and Optoelec
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Designing Nanoporous Materials for
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This program was developed to serve
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Νέα Αυτό-οργανούμε
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A Physical Model to Interpret the E
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FIR study of Ag x (As 33 S 33 Se 33
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Mελέτη Μεικτών Γυαλ
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The Structural Role of Fe and Zn in
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ΕΥΡΕΤΗΡΙΟ ΣΥΓΓΡΑΦΕ
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Κομπίτσας Μ…………
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ΕΥΡΕΤΗΡΙΟ ΣΥΓΓΡΑΦΕ
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W Watson I.M………………4 Weg
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xxiii ÏÎ±Î½ÎµÎ»Î»Î·Î½Î¹Î¿ ÏÏÎ½ÎµÎ´ÏÎ¹Î¿ ÏÏÏÎ¹ÎºÎ·Ï ÏÏÎµÏÎµÎ±Ï ÎºÎ±ÏÎ±ÏÏÎ±ÏÎ·Ï & ÎµÏÎ¹ÏÏÎ·Î¼Î·Ï ...