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- Haman, Zakaryae, et al.
(author)
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Computational identification of efficient 2D Aluminium chalcogenides monolayers for optoelectronics and photocatalysts applications
- 2021
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In: Applied Surface Science. - : Elsevier BV. - 0169-4332 .- 1873-5584. ; 556
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Journal article (peer-reviewed)abstract
- The massive consumption of traditional fossil fuel like oil, coal and natural gas has led to serious environmental issues, which drove the search for cleaner renewable energy sources. One such option is photocatalytic water splitting that has attracted much attention as a viable process for the large scale production of hydrogen as a renewable fuel. Within this perspective, we methodically studied the structural, optoelectronic, and photocatalytic properties of two-dimensional aluminum monochalcogenide monolayers with the chemical formula AlX (X = O, S, Se, and Te) based on the framework of Density Functional Theory (DFT). All considered structures are full relaxed and their thermodynamic stabilities are confirmed by computing the phonon spectrum and Ab Initio Molecular Dynamics (AIMD) simulations. The electronic characteristics are also performed on the basis of both exchange correlation functional GGA-PBE and HSE06 in order to obtain the accurate electronic band gap. According to our calculations, all the four monolayers posses indirect band gaps ranging between 1.937 and 2.46 eV. Furthermore, based on desirable electronic band gaps, the optical performance features were further explored including complex refractive index, absorption coefficient and energy loss function by means of the complex dielectric function. It is found that all the four materials present a high absorption coefficient in the visible and Ultra-Violet regions. Finally, the band edge positions of our monolayers straddle the reduction potential of H2 and the oxidation potential H2O. Also, it was found that the Gibbs free energy of 2D AlO monolayer is 0.02 eV at certain applied external electric field and very close to ideal catalysts which suggest that the AlO monolayer is better candidate for hydrogen production. Our findings demonstrate that AlX monolayers are suitable materials for optoelectronics and hydrogen production via photocatalytic water splitting.
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| 2. |
- Khossossi, Nabil, et al.
(author)
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High-Specific-Capacity and High-Performing Post-Lithium-Ion Battery Anode over 2D Black Arsenic Phosphorus
- 2021
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In: ACS Applied Energy Materials. - : American Chemical Society (ACS). - 2574-0962. ; 4:8, s. 7900-7910
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Journal article (peer-reviewed)abstract
- Nowadays, secondary batteries based on sodium (Na), potassium (K), and magnesium (Mg) stimulate curiosity as eventually high-availability, nontoxic, and eco-friendly alternatives of lithium-ion batteries (LIBs). Against this background, a spate of studies has been carried out over the past few years on anode materials suitable for post-lithium-ion battery (PLIBs), in particular sodium-, potassium- and magnesium-ion batteries. Here, we have consistently studied the efficiency of a 2D alpha-phase arsenic phosphorus (alpha-AsP) as anodes through density functional theory (DFT) basin-hopping Monte Carlo algorithm (BHMC) and ab initio molecular dynamics (AIMD) calculations. Our findings show that alpha-AsP is an optimal anode material with very high stabilities, high binding strength, intrinsic metallic characteristic after (Na/K/Mg) adsorption, theoretical specific capacity, and ultralow ion diffusion barriers. The ultralow energy barriers are found to be 0.066 eV (Na), 0.043 eV (K), and 0.058 eV (Mg), inferior to that of the widely investigated MXene materials. During the charging process, a wide (Na+/K+/Mg2+) concentration storage from which a high specific capacity of 759.24/506.16/253.08 mAh/g for Na/K/Mg ions was achieved with average operating voltages of 0.84, 0.93, and 0.52 V, respectively. The above results provide valuable insights for the experimental setup of outstanding anode material for post-Li-ion battery.
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