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Singh H, Kumar N, Mishra BK. Understanding the by-product formation potential during phenol oxidation from in-situ electro-generated radicals by microalgae harvesting. ENVIRONMENTAL TECHNOLOGY 2021; 42:3533-3545. [PMID: 32085687 DOI: 10.1080/09593330.2020.1733675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/17/2020] [Indexed: 06/10/2023]
Abstract
Advanced oxidation processes have gained colossal attention owing to the prospect of accessible mineralization, but by-product formation and its toxicity evaluation are still inconclusive. The present study demonstrated the performance of electrochemical oxidation process supported with graphite electrodes for the oxidation of phenol from modulated coke oven wastewater. The results suggested that the hydrogen peroxide along with the in-situ synthesized oxidizing agents has the ability to increase the phenol mineralization 1.5 times and by-product toxicity potential on microalgae, Scenedesmus sp. CBIIT(ISM) also revealed that chlorophyll-a synthesis has increased after the electro-oxidation process in coke oven wastewater. The experimental results for phenol mineralization and by-product formation were validated using a mass spectrophotometer.
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Affiliation(s)
- Hariraj Singh
- Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad, India
| | - Niwas Kumar
- Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad, India
| | - Brijesh Kumar Mishra
- Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines) Dhanbad, Dhanbad, India
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Ong SW, Wu J, Thong AZH, Tok ES, Kang HC. Interaction of magnetic transition metal dimers with spin-polarized hydrogenated graphene. J Chem Phys 2013; 138:124709. [PMID: 23556744 DOI: 10.1063/1.4795500] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The coadsorption of hydrogen and transition metal dimers Fe2, Co2, Ni2, and FeCo on graphene is investigated using density functional theory calculations. Our work is motivated by observations that the magnetic moments of these transition metal dimers are large and that hydrogen adsorption partitions the graphene lattice into magnetic subdomains. Thus, we expect the magnetic dimers to interact strongly with the lattice. Our results show that the majority-spin direction of the lattice electronic states depends upon the dimer identity, the lattice spin polarization being in the same direction as the dimer spin polarization for Fe2 and FeCo, but opposite for Co2 and Ni2. We can understand this by examining the electronic density of states of the dimer and the lattice. We also show that coadsorption significantly increases the adsorption energies of both dimer and hydrogen leading to a more strongly-adsorbed dimer, while the bond length and magnetic moment of the upper dimer atom, the latter important for potential magnetic storage applications, are negligibly changed. Our work shows that the coadsorbed hydrogen and metal dimer interact over a long-range, this interaction being mediated by the hydrogen-induced spin-polarization of the graphene lattice. We obtain general insight into how the elemental identity of these magnetic dimers determines the spin-polarized states on the hydrogenated graphene lattice. These results could be important for potential applications of magnetic properties of decorated graphene lattices.
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Affiliation(s)
- S W Ong
- Department of Chemistry, National University of Singapore, Singapore 117543
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Krstic PS, Allain JP, Allouche A, Jakowski J, Dadras J, Taylor CN, Yang Z, Morokuma K, Maeda S. Dynamics of deuterium retention and sputtering of Li–C–O surfaces. FUSION ENGINEERING AND DESIGN 2012. [DOI: 10.1016/j.fusengdes.2011.07.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Bonfanti M, Casolo S, Tantardini GF, Ponti A, Martinazzo R. A few simple rules governing hydrogenation of graphene dots. J Chem Phys 2012; 135:164701. [PMID: 22047257 DOI: 10.1063/1.3650693] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We investigated binding of hydrogen atoms to small polycyclic aromatic hydrocarbons (PAHs)--i.e., graphene dots with hydrogen-terminated edges--using density functional theory and correlated wavefunction techniques. We considered a number of PAHs with three to seven hexagonal rings and computed binding energies for most of the symmetry unique sites, along with the minimum energy paths for significant cases. The chosen PAHs are small enough to not present radical character at their edges, yet show a clear preference for adsorption at the edge sites which can be attributed to electronic effects. We show how the results, as obtained at different levels of theory, can be rationalized in detail with the help of a few simple concepts derivable from a tight-binding model of the π electrons.
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Affiliation(s)
- M Bonfanti
- Dipartimento di Chimica Fisica ed Elettrochimica, Università degli Studi di Milano, v. Golgi 19, 20133 Milan, Italy
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The stretching vibration of hydrogen adsorbed on epitaxial graphene studied by sum-frequency generation spectroscopy. Chem Phys Lett 2011. [DOI: 10.1016/j.cplett.2011.04.025] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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McAfee JL, Poirier B. Quantum dynamics of hydrogen interacting with single-walled carbon nanotubes: multiple H-atom adsorbates. J Chem Phys 2011; 134:074308. [PMID: 21341845 DOI: 10.1063/1.3537793] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
In a previous paper [J. L. McAfee and B. Poirier, J. Chem. Phys. 130, 064701 (2009)], using spin-polarized density functional theory (DFT), the authors reported a binding energy of 0.755 eV, for a single hydrogen atom adsorbed on a pristine (unrelaxed) (5,5) single-walled carbon nanotube (SWNT) substrate. A full three-dimensional (3D) potential energy surface (PES) for the SWNT-H system was also developed, and used in a quantum dynamics calculation to compute all rovibrational bound states, and associated equatorial and longitudinal adsorbate migration rates. A highly pronounced preference for the latter migration pathway at ambient temperatures was observed. In this work, we extend the aforementioned study to include multiple H-atom adsorbates. Extensive DFT calculations are performed, in order to ascertain the most relevant dynamical pathways. For two adsorbates, the SWNT-H-H system is found to exhibit highly site-specific binding, as well as long-range correlation and pronounced binding energy enhancement. The latter effect is even more pronounced in the full-hydrogenation limit, increasing the per-adsorbate binding energy to 2.6 eV. To study migration dynamics, a single-hole model is developed, for which the binding energy drops to 2.11 eV. A global 3D PES is developed for the hole migration model, using 40 radial × 18 cylindrical ab initio geometries, fit to a Fourier basis with radially dependent expansion coefficients (rms error 4.9 meV). As compared with the single-adsorbate case, the hole migration PES does not exhibit separate chemisorption and physisorption wells. The barrier to longitudinal migration is also found to be much lower. Quantum dynamics calculations for all rovibrational states are then performed (using a mixed spectral basis/phase-space optimized discrete variable representation), and used to compute longitudinal migration rates. Ramifications for the use of SWNTs as potential hydrogen storage materials are discussed.
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Affiliation(s)
- Jason L McAfee
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, USA
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Aréou E, Cartry G, Layet JM, Angot T. Hydrogen-graphite interaction: Experimental evidences of an adsorption barrier. J Chem Phys 2011; 134:014701. [DOI: 10.1063/1.3518981] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Senftle F, Grant J, Senftle F. Low-voltage DC/AC electrolysis of water using porous graphite electrodes. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2010.04.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Boukhvalov DW, Katsnelson MI. Chemical functionalization of graphene. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:344205. [PMID: 21715780 DOI: 10.1088/0953-8984/21/34/344205] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Experimental and theoretical results on chemical functionalization of graphene are reviewed. Using hydrogenated graphene as a model system, general principles of the chemical functionalization are formulated and discussed. It is shown that, as a rule, 100% coverage of graphene by complex functional groups (in contrast with hydrogen and fluorine) is unreachable. A possible destruction of graphene nanoribbons by fluorine is considered. The functionalization of infinite graphene and graphene nanoribbons by oxygen and by hydrofluoric acid is simulated step by step.
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Affiliation(s)
- D W Boukhvalov
- Institute for Molecules and Materials, Radboud University Nijmegen, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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Casolo S, Løvvik OM, Martinazzo R, Tantardini GF. Understanding adsorption of hydrogen atoms on graphene. J Chem Phys 2009; 130:054704. [DOI: 10.1063/1.3072333] [Citation(s) in RCA: 281] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Morisset S, Allouche A. Quantum dynamic of sticking of a H atom on a graphite surface. J Chem Phys 2008; 129:024509. [DOI: 10.1063/1.2952685] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kerwin J, Jackson B. The sticking of H and D atoms on a graphite (0001) surface: The effects of coverage and energy dissipation. J Chem Phys 2008; 128:084702. [DOI: 10.1063/1.2868771] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Long range orientation of meta-stable atomic hydrogen adsorbate clusters on the graphite(0 0 0 1) surface. Chem Phys Lett 2007. [DOI: 10.1016/j.cplett.2007.08.064] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Lanzani G, Martinazzo R, Materzanini G, Pino I, Tantardini GF. Chemistry at surfaces: from ab initio structures to quantum dynamics. Theor Chem Acc 2007. [DOI: 10.1007/s00214-006-0201-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Kerwin J, Sha X, Jackson B. Classical Studies of H Atom Trapping on a Graphite Surface†. J Phys Chem B 2006; 110:18811-7. [PMID: 16986871 DOI: 10.1021/jp057136+] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The trapping and sticking of H and D atoms on the graphite (0001) surface is examined over the energy range 0.1-0.9 eV. Total electronic energy calculations based on density functional theory are used to develop a potential energy surface that allows for the full three-dimensional motion of the incident atom and the reconstruction of the bonding carbon atom, which must pucker out of the surface to form a stable bond. Classical methods are used to compute trapping cross sections as a function of incident energy. The C-H bond, once formed, rapidly dissociates without a mechanism to dissipate its excess energy. However, a number of long-lived trapping resonances exist, and for impact parameters below 1 A or so, several percent of the incident H atoms can remain trapped for 1 ps or more. This long-time trapping probability increases significantly when additional lattice degrees of freedom are added to carry energy away from the C-H stretch. Trapping can also increase with an increasing collision impact parameter, as H vibrations parallel to the surface become excited, leaving less energy in the C-H stretch. The trapping cross section at 1 ps reaches a maximum of 0.2 A2 for an H atom energy of 0.3 eV. Assuming that any atoms remaining trapped after 1 ps fully relax and stick, we estimate a lower bound for the sticking probability of H and D to be 0.024 and 0.050, respectively, about an order of magnitude below the experimental values.
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Affiliation(s)
- Jay Kerwin
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Baouche S, Gamborg G, Petrunin VV, Luntz AC, Baurichter A, Hornekaer L. High translational energy release in H2 (D2) associative desorption from H (D) chemisorbed on C(0001). J Chem Phys 2006; 125:084712. [PMID: 16965044 DOI: 10.1063/1.2220565] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Highly energetic translational energy distributions are reported for hydrogen and deuterium molecules desorbing associatively from the atomic chemisorption states on highly oriented pyrolytic graphite (HOPG). Laser assisted associative desorption is used to measure the time of flight of molecules desorbing from a hydrogen (deuterium) saturated HOPG surface produced by atomic exposure from a thermal atom source at around 2100 K. The translational energy distributions normal to the surface are very broad, from approximately 0.5 to approximately 3 eV, with a peak at approximately 1.3 eV. The highest translational energy measured is close to the theoretically predicted barrier height. The angular distribution of the desorbing molecules is sharply peaked along the surface normal and is consistent with thermal broadening contributing to energy release parallel to the surface. All results are in qualitative agreement with recent density functional theory calculations suggesting a lowest energy para-type dimer recombination path.
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Affiliation(s)
- S Baouche
- Physics Department, University of Southern Denmark, DK-5230 Odense, Denmark.
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Andree A, Lay ML, Zecho T, Küpper J. Pair formation and clustering of D on the basal plane of graphite. Chem Phys Lett 2006. [DOI: 10.1016/j.cplett.2006.05.015] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Martinazzo R, Tantardini GF. Quantum study of Eley-Rideal reaction and collision induced desorption of hydrogen atoms on a graphite surface. II. H-physisorbed case. J Chem Phys 2006; 124:124703. [PMID: 16599714 DOI: 10.1063/1.2177655] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Following previous investigation of collision induced (CI) processes involving hydrogen atoms chemisorbed on graphite [R. Martinazzo and G. F. Tantardini, J. Chem. Phys. 124, 124702 (2006)], the case in which the target hydrogen atom is initially physisorbed on the surface is considered here. Several adsorbate-substrate initial states of the target H atom in the physisorption well are considered, and CI processes are studied for projectile energies up to 1 eV. Results show that (i) Eley-Rideal cross sections at low collision energies may be larger than those found in the H-chemisorbed case but they rapidly decrease as the collision energy increases; (ii) product hydrogen molecules are vibrationally very excited; (iii) collision induced desorption cross sections rapidly increase, reaching saturation values greater than 10 A2; (iv) trapping of the incident atoms is found to be as efficient as the Eley-Rideal reaction at low energies and remains sizable (3-4 A2) at high energies. The latter adsorbate-induced trapping results mainly in formation of metastable hot hydrogen atoms, i.e., atoms with an excess energy channeled in the motion parallel to the surface. These atoms might contribute in explaining hydrogen formation on graphite.
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Affiliation(s)
- Rocco Martinazzo
- Department of Physical Chemistry and Electrochemistry and CIMAINA, University of Milan, Via Golgi 19, 20133 Milan, Italy
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Martinazzo R, Tantardini GF. Quantum study of Eley-Rideal reaction and collision induced desorption of hydrogen atoms on a graphite surface. I. H-chemisorbed case. J Chem Phys 2006; 124:124702. [PMID: 16599713 DOI: 10.1063/1.2177654] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Collision induced (CI) processes involving hydrogen atoms on a graphite surface are studied quantum mechanically within the rigid, flat surface approximation, using a time-dependent wave packet method. The Eley-Rideal (ER) reaction and collision induced desorption (CID) cross sections are obtained with the help of two propagations which use different sets of coordinates, a "product" and a "reagent" set. Several adsorbate-substrate initial states of the target H atom in the chemisorption well are considered, and CI processes are studied over a wide range of projectile energy. Results show that (i) the Eley-Rideal reaction is the major reactive outcome and (ii) CID cross sections do not exceed 4 A2 and present dynamic thresholds for low values of the target vibrational quantum number. ER cross sections show oscillations at high energies which cannot be reproduced by classical and quasiclassical trajectory calculations. They are related to the vibrational excitation of the reaction products, which is a rather steep decreasing function of the collision energy. This behavior causes a selective population of the low-lying vibrational states and allows the quantization of the product molecular states to manifest itself in a collisional observable. A peak structure in the CID cross section is also observed and is assigned to the selective population of metastable states of the transient molecular hydrogen.
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Affiliation(s)
- Rocco Martinazzo
- Department of Physical Chemistry and Electrochemistry, and CIMAINA, University of Milan, Via Golgi 19, 20133 Milan, Italy.
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