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Author Yayak, Y.O.; Sozen, Y.; Tan, F.; Gungen, D.; Gao, Q.; Kang, J.; Yagmurcukardes, M.; Sahin, H.
Title First-principles investigation of structural, Raman and electronic characteristics of single layer Ge3N4 Type (up) A1 Journal article
Year 2022 Publication Applied surface science Abbreviated Journal Appl Surf Sci
Volume 572 Issue Pages 151361
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By means of density functional theory-based first-principle calculations, the structural, vibrational and electronic properties of single-layer Ge3N4 are investigated. Structural optimizations and phonon band dispersions reveal that single-layer ultrathin form of Ge3N4 possesses a dynamically stable buckled structure with large hexagonal holes. Predicted Raman spectrum of single-layer Ge3N4 indicates that the buckled holey structure of the material exhibits distinctive vibrational features. Electronic band dispersion calculations indicate the indirect band gap semiconducting nature of single-layer Ge3N4. It is also proposed that single-layer Ge3N4 forms type-II vertical heterostructures with various planar and puckered 2D materials except for single-layer GeSe which gives rise to a type-I band alignment. Moreover, the electronic properties of single-layer Ge3N4 are investigated under applied external in-plane strain. It is shown that while the indirect gap behavior of Ge3N4 is unchanged by the applied strain, the energy band gap increases (decreases) with tensile (compressive) strain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000723664000006 Publication Date 2021-10-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 6.7
Call Number UA @ admin @ c:irua:184752 Serial 6993
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Author Bafekry, A.; Faraji, M.; Fadlallah, M.M.; Khatibani, A.B.; Ziabari, A. abdolahzadeh; Ghergherehchi, M.; Nedaei, S.; Shayesteh, S.F.; Gogova, D.
Title Tunable electronic and magnetic properties of MoSi₂N₄ monolayer via vacancy defects, atomic adsorption and atomic doping Type (up) A1 Journal article
Year 2021 Publication Applied Surface Science Abbreviated Journal Appl Surf Sci
Volume 559 Issue Pages 149862
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The two dimensional MoSi2N4 (MSN) monolayer exhibiting rich physical and chemical properties was synthesized for the first time last year. We have used the spin-polarized density functional theory to study the effect of different types of point defects on the structural, electronic, and magnetic properties of the MSN monolayer. Adsorbed, substitutionally doped (at different lattice sites), and some kind of vacancies have been considered as point defects. The computational results show all defects studied decrease the MSN monolayer band gap. We found out the H-, O-, and P-doped MSN are n-type conductors. The arsenic-doped MSN, and MSN with vacancy defects have a magnetic moment. The MSN with a Si vacancy defect is a half-metallic which is favorable for spintronic applications, while the MSN with a single N vacancy or double vacancy (N + S) defects are metallic, i. e., beneficial as spin filters and chemical sensors.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000655645300001 Publication Date 2021-05-01
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.387 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 3.387
Call Number UA @ admin @ c:irua:179098 Serial 7038
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Author Nematollahi, P.
Title Selectivity of Mo-NC sites for electrocatalytic N₂ reduction : a function of the single atom position on the surface and local carbon topologies Type (up) A1 Journal article
Year 2023 Publication Applied surface science Abbreviated Journal
Volume 612 Issue Pages 155908-155909
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Abstract Transition metal (TM) doped two-dimensional single-atom catalysts are known as a promising class of catalysts for electrocatalytic gas conversion. However, the detailed mechanisms that occur at the surface of these catalysts are still unknown. In the present work, we simulate three Mo-doped nitrogenated graphene structures. In each catalyst, the position of the Mo active site and the corresponding local carbon topologies are different, i.e. MoN4C10 with in-plane Mo atom, MoN4C8 in which Mo atom bridges two adjacent armchair-like graphitic edges, and MoN2C3 in which Mo is doped at the edge of the graphene sheet. Using Density Functional Theory (DFT) calculations we discuss the electrocatalytic activity of Mosingle bondNsingle bondC structures for nitrogen reduction reaction (NRR) with a focus on unraveling the corresponding mechanisms concerning different Mo site positions and C topologies. Our results indicate that the position of the active site centers has a great effect on its electrocatalytic behavior. The gas phase N2 efficiently reduces to ammonia on MoN4C8 via the distal mechanism with an onset potential of −0.51 V. We confirm that the proposed pyridinic structure, MoN4C8, can catalyze NRR effectively with a low overpotential of 0.35 V.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000901469900003 Publication Date 2022-11-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.7; 2023 IF: 3.387
Call Number UA @ admin @ c:irua:192430 Serial 7275
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Author Li, C.-F.; Chen, L.-D.; Wu, L.; Liu, Y.; Hu, Z.-Y.; Cui, W.-J.; Dong, W.-D.; Liu, X.; Yu, W.-B.; Li, Y.; Van Tendeloo, G.; Su, B.-L.
Title Directly revealing the structure-property correlation in Na+-doped cathode materials Type (up) A1 Journal article
Year 2023 Publication Applied surface science Abbreviated Journal
Volume 612 Issue Pages 155810-10
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The introduction of Na+ is considered as an effective way to improve the performance of Ni-rich cathode materials. However, the direct structure-property correlation for Na+ doped NCM-based cathode materials remain unclear, due to the difficulty of local and accurate structural characterization for light elements such as Li and Na. Moreover, there is the complexity of the modeling for the whole Li ion battery (LIB) system. To tackle the above-mentioned issues, we prepared Na+-doped LiNi0.6Co0.2Mn0.2O2 (Na-NCM622) material. The crystal structure change and the lattice distortion with picometers precision of the Na+-doped material is revealed by Cs-corrected scanning transmission electron microscopy (STEM). Density functional theory (DFT) and the recently proposed electrochemical model, i.e., modified Planck-Nernst-Poisson coupled Frumkin-Butler-Volmer (MPNP-FBV), has been applied to reveal correlations between the activation energy and the charge transfer resistance at multiscale. It is shown that Na+ doping can reduce the activation energy barrier from. G = 1.10 eV to 1.05 eV, resulting in a reduction of the interfacial resistance from 297 O to 134 Omega. Consequently, the Na-NCM622 cathode delivers a superior capacity retention of 90.8 % (159 mAh.g(-1)) after 100 cycles compared to the pristine NCM622 (67.5 %, 108 mAh.g(-1)). Our results demonstrate that the kinetics of Li+ diffusion and the electrochemical reaction can be enhanced by Na+ doping the cathode material.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000892940300001 Publication Date 2022-11-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited Open Access OpenAccess
Notes Approved Most recent IF: 6.7; 2023 IF: 3.387
Call Number UA @ admin @ c:irua:192758 Serial 7296
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Author Benedet, M.; Andrea Rizzi, G.; Gasparotto, A.; Gauquelin, N.; Orekhov, A.; Verbeeck, J.; Maccato, C.; Barreca, D.
Title Functionalization of graphitic carbon nitride systems by cobalt and cobalt-iron oxides boosts solar water oxidation performances Type (up) A1 Journal article
Year 2023 Publication Applied surface science Abbreviated Journal
Volume 618 Issue Pages 156652
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract The ever-increasing energy demand from the world population has made the intensive use of fossil fuels an overarching threat to global environment and human health. An appealing alternative is offered by sunlight-assisted photoelectrochemical water splitting to yield carbon-free hydrogen fuel, but kinetic limitations associated to the oxygen evolution reaction (OER) render the development of cost-effective, eco-friendly and stable electrocatalysts an imperative issue. In the present work, OER catalysts based on graphitic carbon nitride (g-C3N4) were deposited on conducting glass substrates by a simple decantation procedure, followed by functionalization with low amounts of nanostructured CoO and CoFe2O4 by radio frequency (RF)-sputtering, and final annealing under inert atmosphere. A combination of advanced characterization tools was used to investigate the interplay between material features and electrochemical performances. The obtained results highlighted the formation of a p-n junction for the g-C3N4-CoO system, whereas a Z-scheme junction accounted for the remarkable performance enhancement yielded by g-C3N4-CoFe2O4. The intimate contact between the system components also afforded an improved electrocatalyst stability in comparison to various bare and functionalized g-C3N4-based systems. These findings emphasize the importance of tailoring g-C3N4 chemico-physical properties through the dispersion of complementary catalysts to fully exploit its applicative potential.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000950654300001 Publication Date 2023-02-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.7 Times cited 11 Open Access OpenAccess
Notes The authors gratefully acknowledge financial support from CNR (Progetti di Ricerca @CNR – avviso 2020 – ASSIST), Padova University (P-DiSC#04BIRD2020-UNIPD EUREKA, DOR 2020–2022), AMGA Foundation (NYMPHEA project), INSTM Consortium (INSTM21PDGASPAROTTO – NANOMAT, INSTM21PDBARMAC – ATENA) and the European Union's Horizon 2020 research and innovation program under grant agreement No 823717 – ESTEEM3. The FWO-Hercules fund G0H4316N 'Direct electron detector for soft matter TEM' is also acknowledged. Many thanks are due to Prof. Luca Gavioli (Università Cattolica del Sacro Cuore, Brescia, Italy) and Dr. Riccardo Lorenzin (Department of Chemical Sciences, Padova University, Italy) for their invaluable technical support.; esteem3reported; esteem3TA Approved Most recent IF: 6.7; 2023 IF: 3.387
Call Number EMAT @ emat @c:irua:196150 Serial 7376
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Author Siriwardane, E.M.D.; Karki, P.; Sevik, C.; Cakir, D.
Title Electronic and mechanical properties of stiff rhenium carbide monolayers: A first-principles investigation Type (up) A1 Journal article
Year 2018 Publication Applied surface science Abbreviated Journal
Volume 458 Issue Pages 762-768
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this study, we predicted two new stable metallic Re-C based monolayer structures with a rectangular (r-ReC2) and a hexagonal (h-Re2C) crystal symmetry using first-principle calculations based on density functional theory. Our results obtained from mechanical and phonon calculations and high-temperature molecular dynamic simulations clearly proved the stability of these two-dimensional (2D) crystals. Interestingly, Re-C monolayers in common transition metal carbide structures (i.e. MXenes) were found to be unstable, contrary to expectations. We found that the stable structures, i.e. r-ReC2 and h-Re2C, display superior mechanical properties over the well-known 2D materials. The Young's modulus for r-ReC2 and h-Re2C are extremely high and were calculated as 351 (1310) and 617 (804) N/m (GPa), respectively. Both materials have larger Young's modulus values than the most of the well-known 2D materials. We showed that the combination of the short strong directional p-d bonds, the high coordination number of atoms in the unit-cell and high valence electron density result in strong mechanical properties. Due to its crystal structure, the r-ReC2 monolayer has anisotropic mechanical properties and the crystallographic direction parallel to the C-2 dimers is stiffer compared to perpendicular direction due to strong covalent bonding within C-2 dimers. h-Re2C was derived from the corresponding bulk structure for which we determined the critical thickness for the dynamically stable bulk-derived monolayer structures. In addition, we also investigated the electronic of these two stable structures. Both exhibit metallic behavior and Re-5d orbitals dominate the states around the Fermi level. Due to their ultra high mechanical stability and stiffness, these novel Re-C monolayers can be exploited in various engineering applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000441400000088 Publication Date 2018-07-11
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0169-4332 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:193776 Serial 7875
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