| 1. |
- Anikina, Ekaterina, et al.
(author)
-
High-capacity reversible hydrogen storage properties of metal-decorated nitrogenated holey graphenes
- 2022
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 47:19, s. 10654-10664
-
Journal article (peer-reviewed)abstract
- Motivated by the need for an effective way of storing hydrogen (H-2), a promising energy carrier, we have performed density functional theory (DFT) calculations with different van der Waals corrections coupled with the statistical thermodynamic analysis and ab initio molecular dynamics (AIMD) on the light-metal decorated nitrogenated holey graphene (C2N) monolayers. We have found that the decoration by selected light metals (Na, Mg, Ca) improves the H2 adsorption on the C2N to the desired levels (> 150 meV/H-2). Moreover, the metal dopants strongly bonded with C2N even at higher doping concentrations, which invalidates the metal clusters formation. Among considered metals, Na and Mg resulted in H-2 storage capacities of 5.5 and 6.9 wt%, respectively, which exceed the target set by the U.S. Department of Energy's for 2025. Thermodynamic analysis and the AIMD simulations were employed to investigate the H-2 sorption at varied conditions of temperature and pressure for practical applications.
|
|
| 2. |
- Anikina, Ekaterina, et al.
(author)
-
Tunning Hydrogen Storage Properties of Carbon Ene-Yne Nanosheets through Selected Foreign Metal Functionalization
- 2020
-
In: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 124:31, s. 16827-16837
-
Journal article (peer-reviewed)abstract
- In this study, we have employed density functional theory with a range of van der Waals corrections to study geometries, electronic structures, and hydrogen (H-2) storage properties of carbon ene-yne (CEY) decorated with selected alkali (Na, K) and alkaline-earth metals (Mg, Ca). We found that all metals, except Mg, bind strongly by donating a major portion of their valence electrons to the CEY monolayers. Thermal stabilities of representative systems, Ca-decorated CEY monolayers, have been confirmed through ab initio molecular dynamics simulations (AIMD). We showed that each metal cation adsorbs multiple H-2 with binding energies (E-bind) considerably stronger than on pristine CEY. Among various metal dopants, Ca stands out with the adsorption of five H-2 per each Ca having E-bind values within the desirable range for effective adsorption/desorption process. The resulting gravimetric density for CEY@Ca has been found around 6.0 wt % (DFT-D3) and 8.0 wt % (LDA), surpassing the U.S. Department of Energy's 2025 goal of 5.5 wt %. The estimated H-2 desorption temperature in CEY@Ca exceeds substantially the boiling point of liquid nitrogen, which confirms its potential as a practical H-2 storage medium. We have also employed thermodynamic analysis to explore the H-2 adsorption/desorption mechanism at varied conditions of temperature and pressure for real-world applications.
|
|
| 3. |
- Hussain, Tanveer, et al.
(author)
-
Sensing of volatile organic compounds on two-dimensional nitrogenated holey graphene, graphdiyne, and their heterostructure
- 2020
-
In: Carbon. - : Elsevier. - 0008-6223 .- 1873-3891. ; 163, s. 213-223
-
Journal article (peer-reviewed)abstract
- Gas-sensing properties of nitrogenated holey graphene (C2N), graphdiyne (GDY) and their van der Waals heterostructure (C2N…GDY) have been studied towards particular volatile organic compounds (VOCs) by means of spin-polarized, dispersion-corrected DFT calculations. We find that VOCs such as acetone, ethanol, propanal, and toluene interact weakly with the GDY monolayer; however, the bindings are significantly enhanced with the C2N monolayer and the hybrid C2N…GDY heterostructure in AB stacking. Electron localization function (ELF) analysis shows that all VOCs are van der Waals bound (physical binding) to the 2D materials, which result in significant changes of the charge density of C2N and GDY monolayers and the C2N…GDY heterostructure. These changes alter the electronic properties of C2N and GDY, and the C2N…GDY heterostructure, upon VOC adsorption, which are investigated by density-of-states plots. We further apply thermodynamic analysis to study the sensing characteristics of VOCs under varied conditions of pressure and temperature. Our findings clearly indicate that the C2N…GDY heterostructure is a promising material for sensing of certain VOCs.
|
|
| 4. |
- Ian, Jason J., et al.
(author)
-
Superalkali functionalized two-dimensional haeckelite monolayers : A novel hydrogen storage architecture
- 2022
-
In: International journal of hydrogen energy. - : Elsevier. - 0360-3199 .- 1879-3487. ; 47:78, s. 33391-33402
-
Journal article (peer-reviewed)abstract
- Exploring efficient storage mediums is the key challenge to accomplish a sustainable hydrogen economy. Material-based hydrogen (H-2) storage is safe, economically viable and possesses high gravimetric density. Here, we have designed a novel H-2 storage architecture by decorating graphene-like haeckelite (r57) sheets with the super-alkali (NLi4) clusters, which bonded strongly with the r57. We have performed van der Waals corrected density functional theory (DFT) calculations to study the structural, electronic, energetic, charge transfer, and H-2 storage properties of one-sided (r57-NLi4) and two-sided (r57-2NLi(4)) coverage of r57 sheets. Exceptionally high H-2 storage capacities of 10.74%, and 17.01% have been achieved for r57-NLi4, and r57-2NLi(4) systems, respectively that comfortably surpass the U.S. Department of Energy's (DOE) targets. Under maximum hydrogenation, the average H-2 adsorption energies have been found as -0.32 eV/H-2, which is ideal for reversible H-2 storage applications. We have further studied the effects of mechanical strain to explore the H-2 desorption mechanism. Statistical thermodynamic analysis has been employed to study the H-2 storage mechanism at varied conditions of pressures and temperatures. Our findings validate the potential of r57-xNLi(4) as efficient H-2 storage materials.
|
|
| 5. |
- Panigrahi, Puspamitra, et al.
(author)
-
Capacity enhancement of polylithiated functionalized boron nitride nanotubes : an efficient hydrogen storage medium
- 2020
-
In: Physical Chemistry, Chemical Physics - PCCP. - : ROYAL SOC CHEMISTRY. - 1463-9076 .- 1463-9084. ; 22:27, s. 15675-15682
-
Journal article (peer-reviewed)abstract
- By using first principles density functional theory simulations, we report detailed geometries, electronic structures and hydrogen (H-2) storage properties of boron nitride nanotubes (BNNTs) doped with selective polylithiated molecules (CLi2). We find that unsaturated bonding of Li-1s states with BNNT significantly enhances the system stability and hinders the Li-Li clustering effect, which can be detrimental for reversible H(2)storage. The H(2)adsorption mechanism is explained on the basis of polarization caused by the cationic Li(+)of CLi(2)molecules bonded with BNNT. The incident H(2)molecules are adsorbed with BNNT-nCLi(2)through electrostatic and van der Waals interactions. We find that with a maximum of 5.0% of CLi(2)coverage on BNNT, an H(2)gravimetric density of up to 4.41 wt% can be achieved with adsorption energies in the range of -0.33 eV per H-2, which is suitable for ambient condition H(2)storage applications.
|
|
| 6. |
- Panigrahi, Puspamitra, et al.
(author)
-
Efficient Sensing of Selected Amino Acids as Biomarker by Green Phosphorene Monolayers : Smart Diagnosis of Viruses
- 2022
-
In: Advanced Theory and Simulations. - : John Wiley & Sons. - 2513-0390. ; 5:10
-
Journal article (peer-reviewed)abstract
- Effective techniques for the detection of selected viruses detection of their amino acids (AAs) constituents are highly desired, especially in the present COVID pandemic. Motivated by this, we have used density functional theory (DFT) simulations to explore the potential applications of green phosphorene monolayer (GPM) as efficient nanobio-sensor. We have employed van der Waals induced calculations to study the ground-state geometries, binding strength, electronic structures, and charge transfer mechanism of pristine, vacancy-induced and metal-doped GPM to detect the selected AAs, such as glycine, proline and aspartic, in both aqueous and non-aqueous media. We find that the interactions of studied AAs are comparatively weak on pristine (-0.49 to -0.76 eV) and vacancy-induced GPM as compared to the metal-doped GPM (-0.62 to -1.22 eV). Among the considered dopants, Ag-doping enhances the binding of AAs to the GPM stronger than the others. In addition to appropriate binding energies, significant charge transfers coupled with measurable changes in the electronic properties further authenticate the potential of GPM. Boltzmann thermodynamic analysis have been used to study the sensing mechanism under varied conditions of temperatures and pressure for the practical applications. Our findings signify the potential of G PM based sensors towards efficient detection of the selected AAs.
|
|
| 7. |
- Panigrahi, Puspamitra, et al.
(author)
-
Two-Dimensional Bismuthene Nanosheets for Selective Detection of Toxic Gases
- 2022
-
In: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 5:2, s. 2984-2993
-
Journal article (peer-reviewed)abstract
- An in-depth understanding of the practical sensing mechanism of two-dimensional (2D) materials is critically important for the design of efficient nanosensors toward environmentally toxic gases. Here, we have performed van der Waals-corrected density functional theory (DFT) simulations along with nonequilibrium Green’s function (NEGF) to investigate the structural, electronic, transport, thermodynamic, and gas-sensing properties of pristine and defect-crafted bismuthene (bBi) sheets toward sulfur- (H2S, SO2) and nitrogen-rich (NH3, NO2) toxic gases. It is revealed that the electrical conductivities of pristine and defective bBi sheets are altered upon the adsorption of incident gases, which have been verified through transport calculation coupled with the work function and electronic density of states. Our calculations disclose that bBi sheets show superior and selective gas-sensing performance toward NO2 molecules among the studied gases due to a significant charge redistribution and more potent adsorption energies. We find that the mono- and divacancy-induced bBi sheets have enhanced sensitivity because the adsorption behavior is driven by a considerable change in the electrostatic potential difference between the sheets and the gas molecules. We further performed statistical thermodynamic analysis to quantify the gas adsorption abilities at the practical temperature and pressures for the studied gas samples. This work divulges the higher sensitivity and selectivity of bBi sheets toward hazard toxins such as NO2 under practical sensing conditions of temperature and pressure.
|
|
| 8. |
- Panigrahi, Puspamitra, et al.
(author)
-
Two-dimensional Janus monolayers of MoSSe as promising sensor towards selected adulterants compounds
- 2021
-
In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 542
-
Journal article (peer-reviewed)abstract
- Selective detection of different types of adulterants present in food items is necessary and efficient nano sensors for such applications are of vital importance. In this study, recently synthesized two-dimensional (2D) Janus monolayer of MoSSe has been explored to detect various food adulterants like formalin (CH2O), histamine (C5H9N3) and hydrogen peroxide (H2O2). By using first principles density functional theory calculations, we find that the incident adulterants weakly bind with pristine MoSSe, however the adsorption energies (E-ads) are significantly improved upon vacancy defects and foreign elements substitutions. Furthermore, the sensing mechanism is studied in presence of water for the applications in practical working conditions. Energetic evaluation shows that both H2O2 and histamine result into stronger E(ads )as compared to formalin over defect induced MoSSe; whereas, the presence of water further enhances the adsorption of H2O2. In addition to the adsorption characteristics, charge transfer mechanism and electronic structures of pristine and defect induced MoSSe monolayers upon the exposure of studied adulterants have also been studied. Boltzmann thermochemical statistics further verified the explicabilities of pristine and defected MoSSe monolayers for in vitro test of adulterants in food products. Suitable E-ads values and measurable changes in the electronic properties indicate the potential of MoSSe monolayers as efficient nano sensors towards selected adulterants for their applications in food processing, biotechnology, healthcare and medical laboratories.
|
|
