| 1. |
- Hussain, T., et al.
(författare)
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Efficient and selective sensing of nitrogen-containing gases by Si2BN nanosheets under pristine and pre-oxidized conditions
- 2019
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Ingår i: Applied Surface Science. - : ELSEVIER SCIENCE BV. - 0169-4332 .- 1873-5584. ; 469, s. 775-780
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Tidskriftsartikel (refereegranskat)abstract
- Motivated by the promise of two-dimensional nanostructures in the field of gas sensing, we have employed van der Waals corrected density functional theory calculations to study the structural, electronic and gas sensing propensities of the recently designed Si2BN monolayer. Our rigorous simulations reveal that the representative members of nitrogen-containing gases (NCGs) such as NO, NO2 and NH3 binds extremely strongly on pristine Si2BN monolayer. However, a strong dissociative adsorption in case of NO and NO2 would poison the Si2BN and ultimately reversibility of the monolayer would be compromised. Exploring the sensing mechanism in more realistic pre-oxidized conditions, the binding characteristics of O-2@Si2BN changed dramatically, resulting into much lower adsorption in associative manner for all NO, NO2 and NH3. A visible change in work function indicates the variation in conductivity of O-2@Si2BN upon the exposure of incident gases. Sustainable values of binding energies would also ensure a quick recovery time that makes O-2@Si2BN an efficient nano sensor for pollutants like NCGs.
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| 2. |
- Hussain, T., et al.
(författare)
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Superior sensing affinities of acetone towards vacancy induced and metallized ZnO monolayers
- 2018
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Ingår i: Applied Surface Science. - : ELSEVIER SCIENCE BV. - 0169-4332 .- 1873-5584. ; 456, s. 711-716
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Tidskriftsartikel (refereegranskat)abstract
- The sensing propensities of acetone molecule towards zinc oxide monolayers (ZnO-ML) have been studied by means of density functional theory (DFT) calculations. Our van der Waals induced first principles calculations revealed that pristine ZnO-ML barely binds acetone, which limits its application as acetone sensing materials. However the formation of vacancies and foreign element doping improves acetone binding drastically. Among several defects, divacancy, and metal doping Li, Sc and Ti functionalization on ZnO-ML has been found the most promising ones. Presence of dangling electrons and partial positive charges in case of vacancy-induced and metallized ZnO-ML respectively, is believed to enhance the binding of acetone on the monolayers. The acetone-ZnO binding behavior has been further explained through studying the electronic properties by density of states and charge transfer mechanism though Bader analysis. Thus defected and metallized ZnO-ML could be a promising nano sensor for efficient sensing/capture of acetone.
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| 3. |
- Panigrahi, P., et al.
(författare)
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Enriching the hydrogen storage capacity of carbon nanotube doped with polylithiated molecules
- 2018
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 444, s. 467-473
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Tidskriftsartikel (refereegranskat)abstract
- In a quest to find optimum materials for efficient storage of clean energy, we have performed first principles calculations to study the structural and energy storage properties of one-dimensional carbon nanotubes (CNTs) functionalized with polylithiated molecules (PLMs). Van der Waals corrected calculations disclosed that various PLMs like CLi, CLi2, CLi3, OLi, OLi2, OLi3, bind strongly to CNTs even at high doping concentrations ensuring a uniform distribution of dopants without forming clusters. Bader charge analysis reveals that each Li in all the PLMs attains a partial positive charge and transform into Li+ cations. This situation allows multiple H2 molecules adsorbed with each Li+ through the polarization of incident H2 molecules via electrostatic and van der Waals type of interaction. With a maximum doping concentration, that is 3CLi2/3CLi3 and 3OLi2/3OLi3 a maximum of 36 H2 molecules could be adsorbed that corresponds to a reasonably high H2 storage capacity with the adsorption energies in the range of −0.33 to −0.15 eV/H2. This suits the ambient condition applications.
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