| 1. |
- Panigrahi, P., et al.
(author)
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Tuning the selective sensing properties of transition metal dichalcogenides (MoX2 X= Se, Te) toward sulfurrich gases
- 2022
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In: Materials Today Chemistry. - : Elsevier. - 2468-5194. ; 26
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Journal article (peer-reviewed)abstract
- There is an urgent need for an efficient sensor to mitigate the effects of toxic pollutants possessing severe impacts on humans and the environment. Motivated by this, we investigated the selected transition metal dichalcogenides (MoX2: X = Se, Te) monolayers toward the toxic sulfur-containing gases, such as H2S and SO2. We employed density functional theory simulations in combination with nonequilibrium Green's function formalism to study the optimized geometries, binding strength, electronic structures, charge transfer mechanism, and transport (current-voltage) characteristics of MoX2 with and without H2S and SO2. Weak binding energies (<-0.30 eV) of H2S/SO2 on pristine MoX2 were enhanced by selectively substituting the latter with elements like As, Ge, and Sb at lower doping concentrations of around 2%. We find that the doped MoX2 strongly adsorbs H2S/SO2 yielding significant changes in their electronic properties, which were the fundamentals for the efficient sensing mechanism and were studied through the density of states and work function calculations. For the practical sensing applica-tions, we considered the statistical thermodynamic analysis to investigate the sensing properties of pristine and doped MoX2 monolayers under varied conditions of the temperatures and pressures. We are confident that our findings would pave the way for synthesizing sensitive and selective transition metal dichalcogenides-based nanosensor toward H2S/SO2.
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| 2. |
- Raval, Dhara, et al.
(author)
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Strain modulating electronic band gaps and SQ efficiencies of semiconductor 2D PdQ(2) (Q = S, Se) monolayer
- 2022
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In: Scientific Reports. - : Springer Nature. - 2045-2322. ; 12:1
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Journal article (peer-reviewed)abstract
- We studied the physical, electronic transport and optical properties of a unique pentagonal PdQ(2) (Q = S, Se) monolayers. The dynamic stability of 2Dwrinkle like-PdQ(2) is proven by positive phonon frequencies in the phonon dispersion curve. The optimized structural parameters of wrinkled pentagonal PdQ(2) are in good agreement with the available experimental results. The ultimate tensile strength (UTHS) was calculated and found that, penta-PdS2 monolayer can withstand up to 16% (18%) strain along x (y) direction with 3.44 GPa (3.43 GPa). While, penta-PdSe2 monolayer can withstand up to 17% (19%) strain along x (y) dirrection with 3.46 GPa (3.40 GPa). It is found that, the penta-PdQ(2) monolayers has the semiconducting behavior with indirect band gap of 0.94 and 1.26 eV for 2D-PdS2 and 2D-PdSe2, respectively. More interestingly, at room temperacture, the hole mobilty (electron mobility) obtained for 2D-PdS2 and PdSe2 are 67.43 (258.06) cm(2) V-1 s(-1) and 1518.81 (442.49) cm(2) V-1 s(-1), respectively. In addition, I-V characteristics of PdSe2 monolayer show strong negative differential conductance (NDC) region near the 3.57 V. The Shockly-Queisser (SQ) effeciency prameters of PdQ(2) monolayers are also explored and the highest SQ efficeinciy obtained for PdS2 is 33.93% at -5% strain and for PdSe2 is 33.94% at -2% strain. The penta-PdQ(2) exhibits high optical absorption intensity in the UV region, up to 4.04 x 10(5) (for PdS2) and 5.28 x 10(5) (for PdSe2), which is suitable for applications in optoelectronic devices. Thus, the ultrathin PdQ(2) monolayers could be potential material for next-generation solar-cell applications and high performance nanodevices.
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| 3. |
- Shaikh, Gaushiya A., et al.
(author)
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Prominent Electrode Material for Na-, K-, and Mg-ion Batteries : 2D beta-Sb Monolayer
- 2022
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In: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 36:13, s. 7087-7095
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Journal article (peer-reviewed)abstract
- The applicability of a two-dimensional beta-antimonene (beta-Sb) monolayer as a negative electrode material for Na-, K-, and Mg-ion batteries has been conducted through first-principles calculations based on density functional theory (DFT). Our findings propose that the hollow and top sites are the energetically most stable adsorption sites for Na, Mg, and K atoms. The chronological adsorption energy, charge transfer, open-circuit voltage, theoretical storage capacity, and metal-ion diffusion barrier energy are investigated. The semiconducting beta-Sb monolayer can provide inherent benefits for transportation of electrons through it, which can deliver tremendous mobility with lower barrier energies of 0.10 eV for Na, 0.09 eV for K, and 0.15 eV for Mg for the diffusion process. The double layers of beta-Sb can adsorb ions on both sides, which leads, at high concentrations (Na2Sb, K2Sb, and Mg2Sb), to theoretical storage capacities of 440.22, 440.22, and 880.45 mAh/gm for Na, K, and Mg ions, respectively. Besides, the electronic formation of beta-Sb changed the nature from semiconducting to metallic under metal-ion adsorption, which significantly enhanced the performance of metal-ion batteries. With the given advantages, we propose that the beta-Sb monolayer can be viewed as a potential material for negative electrodes in Na-, K-, and Mg-ion batteries.
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